If You’re Out Collecting Sweets, It Pays to Look Scary

Only fools mess around with bees, wasps, and hornets as they collect nectar and go about their business while visiting flowering plants.  Relentlessly curious predators and other trouble makers quickly learn that patterns of white, yellow, or orange contrasting with black are a warning that the pain and anguish of being zapped with a venomous sting awaits those who throw caution to the wind.  Through the process of natural selection, many venomous and poisonous animals have developed conspicuously bright or contrasting color schemes to deter would-be predators and molesters from making such a big mistake.

"Red Eft"
The brilliant colors of the “Red Eft”, the terrestrial sub-adult stage of the aquatic Eastern Newt (Notophthalmus viridescens), provide protection not as a form of camouflage, but as a warning to potential predators that “I am inedible” due to the presence of tetrodotoxin, a strong neurotoxin.  Over the generations, natural selection has better enabled the brightest of the individual “Red Efts” to survive to adulthood and reproduce.  Meanwhile, those efts that provided a less obvious visual clue to their toxicity frequently allowed their pursuer to learn of their defense mechanism by the taste-test method.  As one might expect, far fewer of these latter individuals survived to breed and pass along their more cryptic color variation.

Visual warnings enhance the effectiveness of the defensive measures possessed by venomous, poisonous, and distasteful creatures.  Aggressors learn to associate the presence of these color patterns with the experience of pain and discomfort.  Thereafter, they keep their distance to avoid any trouble.  In return, the potential victims of this unsolicited aggression escape injury and retain their defenses for use against yet-to-be-enlightened pursuers.  Thanks to their threatening appearance, the chances of survival are increased for these would-be victims without the need to risk death or injury while deploying their venomous stingers, poisonous compounds, or other defensive measures.

European Paper Wasp
Armed and Dangerous  The yellow-and-black color pattern on this European Paper Wasp signals a potential aggressor that they have come upon a social insect and could be struck with a venomous sting.  The warning colors alone may be all the defenses necessary for this wasp to survive an otherwise fatal encounter.

One shouldn’t be surprised to learn that over time, as these aforementioned venomous, poisonous, and foul-tasting critters developed their patterns of warning colors, there were numerous harmless animals living within close association with these species that, through the process of natural selection, acquired nearly identical color patterns for their own protection from predators.  This form of defensive impersonation is known as Batesian mimicry.

Let’s take a look at some examples of Batesian mimicry right here in the Lower Susquehanna River Watershed.

Suppose for a moment that you were a fly.  As you might expect, you would have plenty to fear while you spend your day visiting flowers in search of energy-rich nectar—hundreds of hungry birds and other animals want to eat you.

Greenbottle Fly
You might not hurt a fly, but plenty of other creatures will.  This Greenbottle Fly relies upon speed and maneuverability to quickly flee predators.
Common Flesh Fly (Sarcophaga species)
Like the Greenbottle Fly, the Common Flesh Fly (Sarcophaga species) needs to be constantly vigilant and survives by being quick to the wing.

If you were a fly and you were headed out and about to call upon numerous nectar-producing flowers so you could round up some sweet treats, wouldn’t you feel a whole lot safer if you looked like those venomous bees, wasps, and hornets in your neighborhood?  Wouldn’t it be a whole lot more fun to look scary—so scary that would-be aggressors fear that you might sting them if they gave you any trouble?

Suppose Mother Nature and Father Time dressed you up to look like a bee or a wasp instead of a helpless fly?  Then maybe you could go out and collect sweets without always worrying about the bullies and the brutes, just like these flies of the lower Susquehanna  do…

FLOWER FLIES/HOVER FLIES

The Common Drone Fly (Eristalis Tenax) is a Honey Bee mimic
The Common Drone Fly (Eristalis tenax) is an unarmed Honey Bee mimic.  This one is gathering nectar on goldenrod flowers.
Transverse Flower Fly (Eristalis transversa)
The Transverse Flower Fly (Eristalis transversa) is another bee mimic.  Members of the genus Eristalis scavenge carcasses in aquatic habitats.  Their larvae are known as rat-tailed maggots, a name that references their long siphons used for breathing surface air while submerged in ponds, streams, and wetlands.
Spilomyia species Flower Fly
Flower flies of the genus Spilomyia are convincing mimics of temperamental yellowjacket wasps.
Yellowjacket Hover Fly
The Yellowjacket Hover Fly (Milesia virginiensis) is usually heard long before it is seen.  It will often approach people and persist with a loud buzzing, sounding more like a bee than a bee does.  Scary, isn’t it?
 Maize Calligrapher
The Maize Calligrapher (Toxomerus politus) is a hover fly mimic of wasps.  Seen here on Indiangrass, it is believed to associate primarily with Corn (Zea mays).
The Narrow-headed Marsh Fly (Helophilus fasciatus) is a wasp mimic.
The Narrow-headed Marsh Fly (Helophilus fasciatus) is a wasp mimic.  Like other mimics of hymenopterans, they are important pollinators of flowering plants.
Syrphus species Hoverfly
This hover fly of the genus Syrphus is another wasp mimic.

TACHINID FLIES

The Feather-legged Fly (Trichopoda species) is a wasp mimic.
The Feather-legged Fly (Trichopoda species) is a wasp mimic.   Its larvae are parasitoids of stink bugs and leaf-footed bugs.

BEE FLIES

Bee Fly (Exoprosopa species)
Bee flies of the genus Exoprosopa convincingly resemble bumble bees.
Bee Fly (Exoprosopa species)
The larvae of Exoprosopa bee flies are believed to be parasitic on the larvae of the parasites of bee and wasp larvae that mature in the soil.  Confused yet?

So let’s review.  If you’re a poor defenseless fly and you want to get your fair share of sweets without being gobbled up by the beasts, then you’ve got to masquerade like a strongly armed member of a social colony—like a bee, wasp, or hornet.  Now look scary and go get your treats.  HAPPY HALLOWEEN!

Hymanoptera: A Look at Some Bees, Wasps, Hornets, and Ants

What’s all this buzz about bees?  And what’s a hymanopteran?  Well, let’s see.

Hymanoptera—our bees, wasps, hornets and ants—are generally considered to be our most evolved insects.  Some form complex social colonies.  Others lead solitary lives.  Many are essential pollinators of flowering plants, including cultivars that provide food for people around the world.  There are those with stingers for disabling prey and defending themselves and their nests.  And then there are those without stingers.  The predatory species are frequently regarded to be the most significant biological controls of the insects that might otherwise become destructive pests.  The vast majority of the Hymanoptera show no aggression toward humans, a demeanor that is seldom reciprocated.

Late summer and early autumn is a critical time for the Hymanoptera.  Most species are at their peak of abundance during this time of year, but many of the adult insects face certain death with the coming of freezing weather.  Those that will perish are busy, either individually or as members of a colony, creating shelter and gathering food to nourish the larvae that will repopulate the environs with a new generation of adults next year.  Without abundant sources of protein and carbohydrates, these efforts can quickly fail.  Protein is stored for use by the larval insects upon hatching from their eggs.  Because the eggs are typically deposited in a cell directly upon the cache of protein, the larvae can begin feeding and growing immediately.  To provide energy for collecting protein and nesting materials, and in some cases excavating nest chambers, Hymanoptera seek out sources of carbohydrates.  Species that remain active during cold weather must store up enough of a carbohydrate reserve to make it through the winter.  Honey Bees make honey for this purpose.  As you are about to see, members of this suborder rely predominately upon pollen or insect prey for protein, and upon nectar and/or honeydew for carbohydrates.

We’ve assembled here a collection of images and some short commentary describing nearly two dozen kinds of Hymanoptera found in the Lower Susquehanna River Watershed, the majority photographed as they busily collected provisions during recent weeks.  Let’s see what some of these fascinating hymanopterans are up to…

SOLITARY WASPS

Great Black Wasp on goldenrod (Solidago species)
A Great Black Wasp on goldenrod (Solidago species).  Like other solitary wasps, a female  Great Black Wasp will sting and paralyze a host insect upon which she’ll deposit her eggs.  After hatching, the larvae will begin consuming the host’s body as a source of protein.  The parasitized insects are often katydids or grasshoppers.
A Great Black Wasp.
A Great Black Wasp feeding on nectar, a source of carbohydrates.  Unlike social bees and wasps, solitary wasps are equipped with a stinger solely used for immobilizing prey, not defending a nest.  They are therefore quite docile and pose little threat to humans.
A Great Black Wasp powdered with pollen.
A Great Black Wasp powdered with pollen.  Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.
Thread-waisted Wasp
A female Thread-waisted wasp (Ammophilia species, probably A. nigricans) drags a paralyzed caterpillar to her excavated nest where she’ll deposit an egg on the body.  After hatching, the larval wasp will feed on the disabled caterpillar.  The protein will enable the larvae to grow, pupate, and later emerge as an adult wasp.
The female Eastern Cicada Killer (Sphecius speciosus) excavates an underground nest with branch tunnels connecting a dozen chambers or more.  As the common name suggests, the female wasp paralyzes a cicada, then makes a strenuous effort to fly and drag it back to the nest for placement in a cell.  Each male wasp egg is deposited upon just one immobilized cicada, but a female egg is provided with a cache of several cicadas to provide adequate protein for growth to a larger size.  Nest cells are sealed with soil, then the larvae hatch in just a couple of days.  Within about two weeks, they have consumed the cicada protein and are fully grown.  Wrapped in a cocoon, they spend the winter in the nest, then pupate in the spring before emerging as a new generation of adults.
The Black-and-yellow Mud Dauber
The Black-and-yellow Mud Dauber (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.
Black-and-yellow Mud Dauber at nest.
A Black-and-yellow Mud Dauber at nest.
Pipe Organ Mud Dauber Nest
The Pipe Organ Mud Dauber builds this elaborate nest in which their eggs and paralyzed spiders are deposited in cells sealed with mud partitions.  After consuming the spiders, the larvae pupate, overwinter, then emerge from their cells as adults during the following spring.  To escape the protection of the nest, the new generation of adults bore through the mud walls.  Adult Pipe Organ Mud Daubers resemble the Great Black Wasp, but have a white or yellow distal segment on their rear legs resembling a pair of light-colored socks.
A closeup of the previous image with the lengths of the nest tubes compressed to show four scavenger flies (Miltogramminae), possibly two species, that have invaded this Pipe Organ Mud Dauber nest.  Scavenger flies are kleptoparasites that victimize various solitary bees and wasps, depositing larvae directly into the host species’ nest cells to consume the protein cache stored therein.

CUCKOO WASPS

Cuckoo Wasp
Cuckoo Wasps (Chrysididae), also known as Emerald Wasps, parasitize the nests of other species of wasps.  Females lay their eggs inside the host’s nest, then flee the scene.  Upon hatching, larval Cuckoo Wasps feed on stockpiles of prey intended for the host species’ offspring.  Like the adult mud daubers that have already matured and departed this nest by digging a hole through the wall of the cell within which they were hatched, the metallic green Cuckoo Wasp in the upper left has just emerged in much the same way.

SWEAT BEES

A Sweat Bee (Lasioglossum species).
A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).
A Sweat Bee (Lasioglossum species).
Sweat Bees (Lasioglossum species) visit human skin to lick up the electrolytes left behind by evaporating perspiration.
A Sweat Bee (Lasioglossum species).
Sweat Bees  in the genus Lasioglossum demonstrate various social behaviors ranging from species that are solitary nesters to those that create colonies with work forces ranging in size from as few as four to as many as hundreds of bees.  Some Lasioglossum practice kleptoparasitism, while others are quite accomplished foragers.
An Augochlorine Green Sweat Bee (Augochlorini).
A female Augochlorine Green Sweat Bee (Augochlorini) collecting nectar on White Snakeroot.  Notice the pollen “baskets” on the rear leg.
An Augochlorine Green Sweat Bee (Augochlorini).
An Augochlorine Green Sweat Bee (Augochlorini).  Sweat bees nest in subterranean cavities and in hollowed out sections of trees.
An Augochlorine Green Sweat Bee (Augochlorini).
A copper-colored Augochlorine Green Sweat Bee (Augochlorini) collecting nectar and dusted with pollen.

LEAFCUTTER AND MASON BEES

Leafcutter Bee
A Leafcutter Bee (Megachile species).  Like Mason Bees, female Mason Bees deposit each of their eggs on a “pollen loaf” within an individual cell inside a preexisting tunnel-like cavity in wood, stone, or in the ground.  Unlike Mason Bees, female Leafcutter Bees cut a circular piece of leaf to create each of the cells in their nest.  After hatching, the larval bee feeds on the pollen loaf, pupates, then emerges from the shelter of the nest to start a new generation, usually during the following year.
A Leafcutter Bee (Megachile species).
A Leafcutter Bee (Megachile species) visiting Wild Bergamot.  Female Leafcutter and Mason Bees lack pollen “baskets” on their rear legs but instead have pollen “brushes” on the underside of the abdomen to gather the protein they need to create a “pollen loaf” for each nest cell.
Leafcutter Bee
A Leafcutter Bee (Megachile species) collecting nectar from White Snakeroot.
A Mason Bee (Osmia species) emerging from a nest cell in spring.
A Mason Bee (Osmia species) emerging from a nest in spring.  Mason Bees create nesting cells within preexisting cavities in wood, stone, and other other supporting structures.  Within the nest cavity, each egg is deposited atop a cache of pollen and nectar, a pollen loaf, then enclosed behind a partition of mud.  The female Mason Bee will usually repeat this process until an entire cavity is filled with cells.  During the following spring, a new generation of adult Mason Bees digs its way through the cell walls to emerge and repeat the process.  These bees readily use paper straws or holes drilled in blocks of wood for nesting.
A mason bee nest box with holes drilled into blocks of wood.
A mason bee nest box with holes drilled into blocks of wood.
Parasitized Mason Bee Nest
Mason Bees seal each cell and the outer end of their nest cavity with mud.  These outer nest cells can been parasitized by a variety of wasps.  Here, the outer cell of a Mason Bee nest has been victimized by a tiny chalcid wasp (looks like another one to the lower left).  Several species of female chalcid wasps (native Monodontomerus species or non-native Pteromalus venustus) enlarge weak points in the outer partition of a mason bee nest, then sting and paralyze the larval bee inside before depositing their eggs.  Within the cell. the wasp larvae consume the larval Mason Bee and the “pollen loaf” provided for its growth.  These same parasitic wasps prey upon Leafcutter Bees as well.

BUMBLE BEES, CARPENTER BEES, HONEY BEES, AND DIGGER BEES

Common Eastern Bumble Bee
A Common Eastern Bumble Bee (Bombus impatiens) collecting nectar and pollen on goldenrod.  Bumble bees are our sole native group of social bees.  Their wax nests are built in a burrow or other shelter.  The eggs are deposited in cells along with a supply of pollen for nourishing the larvae upon hatching.  Honey is stored in “honey pots” within the nest.  New queens are produced along with male bees during the late-summer and fall.  Only the new generation of fertilized queens survive the winter to lay eggs and produce workers to construct a new nest.
Common Eastern Bumble Bees
A pair of Common Eastern Bumble Bees collecting nectar and becoming dusted with pollen.  Their fuzzy coats and semi-warm-blooded metabolism allows them to be active in cooler weather than is tolerated by other bees.
A Common Eastern Bumble Bee pollinating a Great Rhododendron flower.
Flowering plants including the Great Rhododendron find success attracting pollinators to their reproductive blossoms by offering carbohydrate-rich nectar to insects like this Eastern Bumble Bee.  The yellow spots on the flower’s upper petal help to guide visitors toward their sweet treat.
Eastern Carpenter Bee
An Eastern Carpenter Bee feeding on goldenrod nectar.  Compare the almost hairless abdomen to that of the bumble bees.  Carpenter bees are semi-social insects.  Females lay their eggs in cells within galleries bored into wood.  These nests are completed with great precision, avoiding creation of any second entrance by mistakenly breaching the outer surface of the excavated wood.  Each egg/larvae is provided with a supply of protein-rich pollen.  Males often hover outside their mate’s nest to prevent competing males from entering the area.
A Honey Bee visiting goldenrod alongside Common Eastern Bumble Bees.
A worker Honey Bee, a female member of a sisterhood of foragers from a nearby hive, visits goldenrod alongside Common Eastern Bumble Bees.  Honey Bees were brought to North America during the 1620s, the earliest years of the trans-Atlantic migration of European colonists, to pollinate cultivated plants and to provide a reliable source of honey and beeswax.  Within the Honey Bee’s social structure, the queen of each hive lays the eggs to produce the female worker bees.  Once each year, male drones are produced along with a new generation of queens.
Honey Bee Hive
In nature, Honey Bees build hives in tree cavities.  Recently, this colony constructed a hive in a screech owl nest box at susquehannawildlife.net headquarters.  To provide protein for the hatching larvae, worker bees collect pollen and deposit it within the hexagonal cells of the vertically aligned beeswax combs.  After an egg is deposited upon the pollen cache, each cell is sealed with more beeswax.  Young females tend these nest combs before maturing and becoming foraging worker bees.
Bee Hive Display
In apiculture, Honey Bees are raised in man-made hives.  This Pennsylvania Association of Beekeepers display gives visitors to the Pennsylvania Farm Show in Harrisburg a look at the inner workings of a live bee hive.  Nectar collected by worker bees is turned into honey to provide the supply of carbohydrates needed to fuel the colony through the winter.  Note the honeycombs on the glass.
A possible Small Carpenter Bee Ceratina species).
A possible Small Carpenter Bee (Ceratina species) visiting White Snakeroot.  Small Carpenter Bees nest inside hollow stems and twigs.  Some species are eusocial, with a queen’s daughters and sisters sharing responsibility for finding food and rearing the young.  Females overwinter inside a one of the excavated stems and begin a new nest there in the spring.
A Digger Bee (possibly Melissodes species).
A Digger Bee (possibly Melissodes species) with “pollen baskets” full of pollen collected from nearby flowers.  Digger Bees in the genus Melissodes are often known as the Long-horned Bees.  These social insects excavate underground nests and many species practice communal living.

SCOLIID WASPS

Two-spotted Scoliid Wasp
The Two-spotted Scoliid Wasp (Scolia dubia), also known as the Blue-winged Scoliid Wasp, is most frequently observed feeding on nectar.  Scoliid wasps are solitary nesters, though they may assemble into groups while visiting flowers.  They often ignore the presence of humans and are seldom disturbed by their presence.  Females seek out the burrowing grubs of beetles including the Green June Bug (Cotinis nitida) and possibly the Japanese Beetle.  After stinging a grub to paralyze it, the wasp will deposit her egg on its body, then bury it.  Upon hatching, the larval wasp will feed on the grub for nourishment as it grows.
June Bugs eating watermelon.
Don’t like having your watermelon overrun by Green June Bugs while you’re eating?  Then you ought to go out of your way to be nice to the Two-spotted Scoliid Wasp.
The Double-banded Scoliid
The Double-banded Scoliid (Scolia bicincta) parasitizes beetle larvae as hosts for its larvae.  For carbohydrates it relishes flower nectar.

PAPER WASPS

Northern Paper Wasp
A Northern Paper Wasp (Polistes fuscatus).  Paper wasps prey upon numerous garden pests, particularly caterpillars, to collect protein.  Though they are social insects equipped with stingers to subdue their victims and defend their nests, paper wasps are surprisingly docile.
The Northern Paper Wasp
A Northern Paper Wasp (Polistes fuscatus) feeding on nectar from a goldenrod flower.
A Northern Paper Wasp harvesting wood pulp
A Northern Paper Wasp harvesting wood pulp from the side of a mason bee nest box at susquehannawildlife.net headquarters.  The pulp is chewed in the wasp’s saliva to create the paper used to construct the colony’s open-cell nest.
Guinea Paper Wasps (Polistes exclamans) at their nest.
Common Paper Wasps (Polistes exclamans), also known as Guinea Paper Wasps, at their open-cell nest.  This and the nests of most other paper wasps are suspended on a filament or a pedicle.  Many paper wasps can excrete an ant repellent on this section of the nest in an effort to prevent invasion.  Like many other social hymenopterans, a defending wasp can secrete a pheromone venom during the stinging process to warn the colony of danger at the nest.  In winter, Common Paper Wasps seek shelter in stumps and other locations to hibernate.
European Paper Wasp
The European Paper Wasp (Polistes dominula) is a non-native species which builds nests in man-made structures including bird houses.  To collect protein, they prey on a wide selection of insects and other invertebrates.  As such, European Paper Wasps are widespread and successful here in North America.

YELLOWJACKETS AND HORNETS

An Eastern Yellowjacket
An Eastern Yellowjacket feeding on lanternfly honeydew.  Eastern Yellowjackets derive much of their success from being generalists, collecting carbohydrates from nearly any sweet source, natural or man made.  They are quite fond of ripe fruits, flower nectar, and sugary snacks and drinks, especially soda.  Protein for nourishing their larvae is derived from the wide variety invertebrates upon which they prey and from carrion.  These foods are chewed into a paste form in preparation for placement into the brood cells.
An Eastern Yellowjacket.
A subterranean colony of Eastern Yellowjackets is started anew each spring by a young queen that has survived winter hibernation in diapause, a state of interrupted development.  She constructs the new nest’s first cells using pulp made by chewing rotting wood.  The first brood of workers scales up construction while the queen continues producing eggs.  At the nest, these social insects will viciously attack anyone or anything perceived to be a threat, so give them their space and leave them alone.  Many yellowjacket infestations of homes and other buildings are the work of non-native German Yellowjacket (Vespula germanica) [not shown], an invasive species that constructs paper nests in void spaces including walls and attics.
Robber Fly consuming an Eastern Yellowjacket
Yellowjackets may be moody and aggressive, but they do fall victim to a number of predators.  A Robber Fly (Promachus species) has taken down and is devouring this Eastern Yellowjacket.
A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew deposits
A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew on a Tree-of-heaven (Ailanthus altissima).  In the absence of nectar-producing flowers, many bees, yellowjackets, and hornets have turned to the invasive lanternfly and Ailanthus combo to turn the sun’s energy into the carbohydrates they need.  For protein, they prey upon spiders, flies, caterpillars, and a variety of other insects.
A Bald-faced Hornet collecting wood pulp from the surface of a weathered picnic table.
To create paper for nest construction, this Bald-faced Hornet is collecting wood pulp from the surface of a weathered picnic table.  Away from the nest, these hornets demonstrate a calm, carefree demeanor and can be closely observed.
Bald-faced Hornet Nest
A Bald-faced Hornet nest in a pine tree.  These hives are strictly temporary.  Within the nest, a generation of drones (males) and new queens are produced late each year.  These wasps leave the colony to mate.  With the arrival of freezing weather, all inhabitants within the nest, including the old queen, perish, as do the drones that departed to breed.  Only the new queens survive winter hibernation to propagate the next generation of wasps,  starting with the workers needed to construct a fresh nest and reestablish the colony.
Bald-faced Hornets Peering from Nest
Did you ever get the feeling you’re being watched?  Don’t go messing around with Bald-faced Hornet nests.  The occupants therein, like other social bees, wasps, and hornets, are equipped with stingers and venom for defending their colony.  This is an adaptation that has developed over time to assure the survival of populations of these insects.  Think about it this way, a solitary wasp that loses a nest loses only their individual brood of offspring.  There is minimal impact on the wider local population of such insects.  Conversely, a social wasp or hornet that loses a nest loses an entire colony, possibly negating the benefits of their cooperative behavior and threatening the survival of the species.  Insects that cooperate to build societies for survival can be more vulnerable to the catastrophic impacts of certain circumstances like disease, weather, and invasion of their colonies.  Therefore, natural selection has provided them with contingencies for these dangers, for example, the instinct to construct protective shelters and the adaptation of stingers and venom for defense against intruders and would-be predators.  Oh, and by the way, the Bald-faced Hornet can spray venom, often aiming for the eyes, so keep your distance.
European Hornets
European Hornets (Vespa crabro), an introduced species, are predatory on a variety of flying insects for protein.  For carbohydrates they are attracted to sweets like this lanternfly honeydew on Tree-of-heaven.
European Hornets constructing a nest in a tree cavity.
European Hornets constructing a paper nest in a tree cavity.

POTTER WASPS

A Potter Wasp (Eumenes species, probably E. fraturnus) hovering near a European Paper Wasp.
A potter wasp (Eumenes species), probably a Fraternal Potter Wasp (E. fraternus), hovering near a European Paper Wasp on Partridge Pea.  The female potter wasp builds a small mud nest resembling a tiny clay pot.  One of her eggs is inserted and left hanging on a thin thread.  Then a paralyzed caterpillar is deposited as a source of protein to nourish the larva upon hatching.  Lastly, the pot is sealed with a lid made of wet mud.  Upon maturing, the new generation of adult wasps perform a pottery breaking to emerge and take flight.

ANTS

Field Ants (Formica species, possibly Formica pallidefulva) clearing the entrance to their underground nest.
Field Ants (Formica species, possibly Formica pallidefulva) clear the entrance to their underground nest.  Field ants are eusocial insects, they work in concert to build, maintain, and defend the nest, rear young, and find food.  There is no social caste system.  Field Ants are predators and scavengers when collecting protein.  For carbohydrates they often rely on the honeydew produced by aphids.  As a method of improving and sustaining the production of honeydew, some ant species will tend colonies of aphids by moving the younger individuals from depleted portions of plants to more healthy tissue.  Field Ant nests contain chambers used for a variety of functions including raising young and storing food.  Some nests include multiple queens and some colonies consist of more than one nest.   Ants in the genus Formica are weaponized; they can spray formic acid to repel intruders and defend their colony.

We hope this brief but fascinating look at some of our more common bees, wasps, hornets, and ants has provided the reader with an appreciation for the complexity with which their food webs and ecology have developed over time.  It should be no great mystery why bees and other insects, particularly native species, are becoming scarce or absent in areas of the Lower Susquehanna River Watershed where the landscape is paved, hyper-cultivated, sprayed, mowed, and devoid of native vegetation, particularly nectar-producing plants.  Late-summer and autumn can be an especially difficult time for hymanopterans seeking the sources of proteins and carbohydrates needed to complete preparations for next year’s generations of these valuable insects.  An absence of these staples during this critical time of year quickly diminishes the diversity of species and begins to tear at the fabric of the food web.  This degradation of a regional ecosystem can have unforeseen impacts that become increasingly widespread and in many cases permanent.

A farmland desert.

A farmland desert.
How can anyone be surprised by the absence of bees and other pollinators in farmland? Manicured and cultivated ground offers little in the way of year-round shelter and food sources for insects and other wildlife.
A savanna-like habitat.
This savanna-like habitat on a south-facing slope provides the abundance of nectar-producing, pollen-rich wildflowers needed to nourish a diverse population of insects including bees, wasps, hornets, and ants.  Goldenrods, asters, and White Snakeroot are some of their late-season favorites.

Editor’s Note: No bees, wasp, hornets, or ants were harmed during this production.  Neither was the editor swarmed, attacked, or stung.  Remember, don’t panic, just observe.

SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York, NY.

(If you’re interested in insects, get this book!)

Four Common Grasshoppers

Grasshoppers are perhaps best known for the occasions throughout history when an enormous congregation of these insects—a “plague of locusts”—would assemble and rove a region to feed.  These swarms, which sometimes covered tens of thousands of square miles or more, often decimated crops, darkened the sky, and, on occasion, resulted in catastrophic famine among human settlements in various parts of the world.

The largest “plague of locusts” in the United States occurred during the mid-1870s in the Great Plains.  The Rocky Mountain Locust (Melanoplus spretus), a grasshopper of prairies in the American west, had a range that extended east into New England, possibly settling there on lands cleared for farming.  Rocky Mountain Locusts, aside from their native habitat on grasslands, apparently thrived on fields planted with warm-season crops.  Like most grasshoppers, they fed and developed most vigorously during periods of dry, hot weather.  With plenty of vegetative matter to consume during periods of scorching temperatures, the stage was set for populations of these insects to explode in agricultural areas, then take wing in search of more forage.  Plagues struck parts of northern New England as early as the mid-1700s and were numerous in various states in the Great Plains through the middle of the 1800s.  The big ones hit between 1873 and 1877 when swarms numbering as many as trillions of grasshoppers did $200 million in crop damage and caused a famine so severe that many farmers abandoned the westward migration.  To prevent recurrent outbreaks of locust plagues and famine, experts suggested planting more cool-season grains like winter wheat, a crop which could mature and be harvested before the grasshoppers had a chance to cause any significant damage.  In the years that followed, and as prairies gave way to the expansive agricultural lands that presently cover most of the Rocky Mountain Locust’s former range, the grasshopper began to disappear.  By the early years of the twentieth century, the species was extinct.  No one was quite certain why, and the precise cause is still a topic of debate to this day.  Conversion of nearly all of its native habitat to cropland and grazing acreage seems to be the most likely culprit.

The critically endangered Eskimo Curlew (Numenius borealis), a species not photographed since 1962 and not confirmed since 1963, fed on Rocky Mountain Locusts during its spring migration through the Great Plains.  Excessive hunting and conversion of grasslands to agriculture are believed responsible for the bird’s demise.  (United States Fish and Wildlife Service image by Christina Nelson)

In the Mid-Atlantic States, the mosaic of the landscape—farmland interspersed with a mix of forest and disturbed urban/suburban lots—prevents grasshoppers from reaching the densities from which swarms arise.  In the years since the implementation of “Green Revolution” farming practices, numbers of grasshoppers in our region have declined.  Systemic insecticides including neonicotinoids keep grasshoppers and other insects from munching on warm-season crops like corn and soybeans.  And herbicides including 2,4-D (2,4-Dichlorophenoxyacetic acid) have, in effect, become the equivalent of insecticides, eliminating broadleaf food plants from the pasturelands and hayfields where grasshoppers once fed and reproduced in abundance.  As a result, few of the approximately three dozen species of grasshoppers with ranges that include the Lower Susquehanna River Watershed are common here.  Those that still thrive are largely adapted to roadsides, waste ground, and small clearings where native and some non-native plants make up their diet.

Here’s a look at four species of grasshoppers you’re likely to find in disturbed habitats throughout our region.  Each remains common in relatively pesticide-free spaces with stands of dense grasses and broadleaf plants nearby.

CAROLINA GRASSHOPPER

Dissosteira carolina

Carolina Grasshopper
The Carolina Grasshopper, also known as the Carolina Locust or Quaker, is one of the band-winged grasshoppers.  It is commonly found along roadsides and on other bare ground near stands of tall grass and broadleaf plants.
Carolina Grasshopper
The Carolina Grasshopper is variable in color, ranging from very dark brown…
Carolina Grasshopper
…to a rich tan or khaki shade.  These earth-tone colors provide the insect with effective camouflage while spending time on the ground.
Carolina Grasshopper wing
The Carolina Grasshopper is most readily detected and identified when it flies.  The colors of the wings resemble those of the Mourning Cloak butterfly.
Great Black Wasp on goldenrod.
Carolina Grasshoppers are among the preferred victims of Great Black Wasps (Sphex pensylvanicus).  A female wasp stings the grasshopper to paralyze it, then drags it away to one of numerous cells in an underground burrow where she lays an egg on it.  The body of the disabled grasshopper then provides nourishment for the larval wasp.

DIFFERENTIAL GRASSHOPPER

Melanoplus differentialis

Differential Grasshopper nymph.
Differential Grasshopper nymph with small “fairy wings”.
Differential Grasshopper
An adult female Differential Grasshopper with fully developed wings.
An adult female Differential Grasshopper
An adult female Differential Grasshopper

TWO-STRIPED GRASSHOPPER

Melanoplus bivittatus

Two-striped Grasshopper nymph.
An early-stage Two-striped Grasshopper nymph.
Two-striped Grasshopper nymph.
A Two-striped Grasshopper nymph in a later stage.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.  Note the pale stripe originating at each eye and joining near the posterior end of the wings to form a V-shaped pattern.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.

RED-LEGGED GRASSHOPPER

Melanoplus femurrubrum

A Red-legged Grasshopper hiding in dense urban vegetation.
An adult male Red-legged Grasshopper hiding in dense urban vegetation.
Red-legged Grasshopper
The Red-legged Grasshopper may currently be our most abundant and widespread species.
Red-legged Grasshopper
An adult male Red-legged Grasshopper.
Red-legged Grasshopper
An adult female Red-legged Grasshopper.

Protein-rich grasshoppers are an important late-summer, early-fall food source for birds.  The absence of these insects has forced many species of breeding birds to abandon farmland or, in some cases, disappear altogether.

During the mid-twentieth century, the Cattle Egret (Bubulcus ibis), a notoriously nomadic species, transited the Atlantic from Africa to colonize the Americas…and they did it without any direct assistance from humans.  During the 1970s and early 1980s, a nesting population of Cattle Egrets on river islands adjacent to the Susquehanna’s Conejohela Flats off Washington Boro was the largest inland rookery in the northeastern United States.  The Lancaster County Bird Club censused the birds each August and found peak numbers in 1981 (7,580).  During their years of abundance, V-shaped flocks of Cattle Egrets from the rookery islands ventured into grazing lands throughout portions of Lancaster, York, Dauphin, and Lebanon Counties to hunt grasshoppers.  These daily flights were a familiar summertime sight for nearly two decades.  Then, in the early 1980s, reductions in pastureland acreage and plummeting grasshopper numbers quickly took their toll.  By 1988, the rookery was abandoned.  The Cattle Egrets had moved on.  (Vintage 33 mm image)
During the summer and early fall, juvenile and adult Ring-necked Pheasants feed heavily on grasshoppers.  Earlier and more frequent mowing along with declining numbers of grasshoppers on farmlands due to an increase in pesticide use were factors contributing to the crash of the pheasant population in the early 1980s.
Wild Turkey
To the delight of Wild Turkeys, each of the four species of grasshoppers shown above frequents clearings and roadsides adjacent to forest areas.  While changes in grasshopper distribution have been detrimental to populations of birds like pheasants, they’ve created a feeding bonanza for turkeys.
Wild Turkeys feeding on grasshoppers along a forest road.
Wild Turkeys feeding on an abundance of grasshoppers along a forest road.
An American Kestrel feeds on a grasshopper while ignoring the abundance of Spotted Lanternflies swarming the adjacent utility pole.  In Susquehanna valley farmlands, grasshopper and kestrel numbers are down.  Lanternflies, on the other hand, have got it made.
Early Successional Growth
Maintaining areas bordering roads, forests, wetlands, farmlands, and human development in a state of early succession can provide and ideal mix of mature grasses and broadleaf plants for grasshoppers, pollinators, birds, and other wildlife.

Photo of the Day

Magnolia Leaf-footed Bug
At first glance, this insect might be mistaken for a Brown Marmorated Stink Bug.  It is, however, a native species, a Magnolia Leaf-footed Bug (Leptoglossus fulvicornis).  Because it feeds almost exclusively on trees in the genus Magnolia, and because the three members of the genus native to the lower Susquehanna valley, Umbrella Magnolia (M. tripetala), Cucumber Tree (M. acuminata), and Sweetbay (M. virginiana), each have a very limited distribution here, this insect’s presence in the watershed is largely dependent on widespread introductions of ornamental magnolias and native transplants including Southern Magnolia (Magnolia grandiflora).  Adult Magnolia Leaf-footed Bugs overwinter in leaf litter beneath the host trees.  In spring, females lay their eggs in rows along the midrib of the leaves where they are often victims of parasitoid wasps including Gyron pennsylvanicum.  The surviving nymphs and the adults feed on the tree’s leaves and fruits, causing little harm to its overall health.

Photo of the Day

An "Annual Cicada" (Neotibicen) dries its wings after emerging from its exuvia.
The Eastern Scissor Grinder (Neotibicen winnemanna), a species of “Annual Cicada” or “Dog-day Cicada”, dries its wings after emerging from its exoskeleton (exuvia).  After two to five years of subterranean life as a nymph, this adult will soon be ready to fly into the treetops in search of a mate.  There is a sense of urgency.  Summer’s end will bring its life to an end as well.

Shorebirds and More at Bombay Hook National Wildlife Refuge

Have you purchased your 2023-2024 Federal Duck Stamp?  Nearly every penny of the 25 dollars you spend for a duck stamp goes toward habitat acquisition and improvements for waterfowl and the hundreds of other animal species that use wetlands for breeding, feeding, and as migration stopover points.  Duck stamps aren’t just for hunters, purchasers get free admission to National Wildlife Refuges all over the United States.  So do something good for conservation—stop by your local post office and get your Federal Duck Stamp.

2023-2024 Federal Duck Stamp. Your Federal Duck Stamp is your free pass to visit the nation's National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.
Your Federal Duck Stamp is your admission ticket for entry into many of the country’s National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.

Still not convinced that a Federal Duck Stamp is worth the money?  Well then, follow along as we take a photo tour of Bombay Hook National Wildlife Refuge.  Numbers of southbound shorebirds are on the rise in the refuge’s saltwater marshes and freshwater pools, so we timed a visit earlier this week to coincide with a late-morning high tide.

Northern Bobwhite
This pair of Northern Bobwhite, a species now extirpated from the Lower Susquehanna River Watershed and the rest of Pennsylvania, escorted us into the refuge.  At Bombay Hook, they don’t waste your money mowing grass.  Instead, a mosaic of warm-season grasses and early successional growth creates ideal habitat for Northern Bobwhite and other wildlife.
Shearness Pool at Bombay Hook N.W.R.
Twice each day, high tide inundates mudflats in the saltwater tidal marshes at Bombay Hook prompting shorebirds to move into the four man-made freshwater pools.  Birds there can often be observed at close range.  The auto tour route through the refuge primarily follows a path atop the dikes that create these freshwater pools.  Morning light is best when viewing birds on the freshwater side of the road, late-afternoon light is best for observing birds on the tidal saltwater side.
Great Blue Heron
A Great Blue Heron at high tide on the edge of a tidal creek that borders Bombay Hook’s tour route at Raymond Pool.
Semipalmated Sandpipers
Semipalmated Sandpipers stream into Raymond Pool to escape the rising tide in the salt marsh.
Semipalmated Sandpipers and Short-billed Dowitcher
More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.
Short-billed Dowitchers
Two more Short-billed Dowitchers on the way in.
Sandpipers, Avocets, Egrets, and Mallards
Recent rains have flooded some of the mudflats in Bombay Hook’s freshwater pools. During our visit, birds were often clustered in areas where bare ground was exposed or where water was shallow enough to feed.  Here, Short-billed Dowitchers in the foreground wade in deeper water to probe the bottom while Semipalmated Sandpipers arrive to feed along the pool’s edge.  Mallards, American Avocets, and egrets are gathered on the shore.
Short-billed Dowitchers
More Short-billed Dowitchers arriving to feed in Raymond Pool.
Semipalmated Sandpipers
Hundreds of Semipalmated Sandpipers gathered in shallow water where mudflats are usually exposed during mid-summer in Raymond Pool.
Hundreds of Semipalmated Sandpipers, several Short-billed Dowitchers, and some Forster’s Terns (Sterna forsteri) crowd onto a mud bar at Bear Swamp Pool.
Semipalmated Sandpipers, Forster's Terns, and a Short-billed Dowitcher
A zoomed-in view of the previous image showing a tightly packed crowd of Semipalmated Sandpipers, Forster’s Terns, and a Short-billed Dowitcher (upper left).
Short-billed Dowitchers
Short-billed Dowitchers wading to feed in the unusually high waters of Raymond Pool.
Short-billed Dowitchers, American Avocets, and a Snowy Egret
Short-billed Dowitchers, American Avocets, and a Snowy Egret in Raymond Pool.  A single Stilt Sandpiper (Calidris himantopus) can been seen flying near the top of the flock of dowitchers just below the egret.
Stilt Sandpiper among Short-billed Dowitchers
Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.
American Avocets
American Avocets probe the muddy bottom of Raymond Pool.
Dunlin and Short-billed Dowitchers
Among these Short-billed Dowitchers, the second bird from the bottom is a Dunlin. This sandpiper, still in breeding plumage, is a little bit early.  Many migrating Dunlin linger at Bombay Hook into October and even November.
Least Sandpiper
This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool.
Lesser Yellowlegs
Lesser Yellowlegs at Bear Swamp Pool
Greater Yellowlegs
A Greater Yellowlegs at Bear Swamp Pool.
Caspian Tern
A Caspian Tern patrolling Raymond Pool.
Marsh Wren singing
The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.
Marsh Wren Nest
This dome-shaped Marsh Wren nest is supported by the stems of Saltwater Cordgrass (Sporobolus alterniflorus), a plant also known as Smooth Cordgrass.  High tide licks at the roots of the cordgrass supporting the temporary domicile.
Seaside Dragonlet
By far the most common dragonfly at Bombay Hook is the Seaside Dragonlet (Erythrodiplax berenice).  It is our only dragonfly able to breed in saltwater.  Seaside Dragonlets are in constant view along the impoundment dikes in the refuge.
Red-winged Blackbird
Red-winged Blackbirds are still nesting at Bombay Hook, probably tending a second brood.
Bobolink
Look up!   A migrating Bobolink passes over the dike at Shearness Pool.
Mute Swans and Canada Geese
Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.
Trumpeter Swans
A pair of Trumpeter Swans (Cygnus buccinator) as seen from the observation tower at Shearness Pool.  Unlike gregarious Tundra and Mute Swans, pairs of Trumpeter Swans prefer to nest alone, one pair to a pond, lake, or sluggish stretch of river.  The range of these enormous birds was restricted to western North America and their numbers were believed to be as low as 70 birds during the early twentieth century.  An isolated population consisting of several thousand birds was discovered in a remote area of Alaska during the 1930s allowing conservation practices to protect and restore their numbers.  Trumpeter Swans are slowly repopulating scattered east coast locations following recent re-introduction into suitable habitats in the Great Lakes region.
Great Egret
A Great Egret prowling Shearness Pool.
Snowy Egret
A Snowy Egret in Bear Swamp Pool.
A hen Wood Duck (second from right) escorts her young.
Wood Ducks in Bear Swamp Pool.
Black-necked Stilt and young.
A Bombay Hook N.W.R. specialty, a Black-necked Stilt and young at Bear Swamp Pool.

As the tide recedes, shorebirds leave the freshwater pools to begin feeding on the vast mudflats exposed within the saltwater marshes.  Most birds are far from view, but that won’t stop a dedicated observer from finding other spectacular creatures on the bay side of the tour route road.

Bombay Hook National Wildlife Refuge protects a vast parcel of tidal salt marsh and an extensive network of tidal creeks. These areas are not only essential wildlife habitat, but are critical components for maintaining water quality in Delaware Bay and the Atlantic.
Atlantic Horseshoe Crab
The shells of expired Atlantic Horseshoe Crabs were formerly widespread and common among the naturally occurring flotsam along the high tide line on Delaware Bay.  We found just this one during our visit to Bombay Hook.  Man has certainly decimated populations of this ancient crustacean during recent decades.
As the tide goes out, it’s a good time for a quick walk into the salt marsh on the boardwalk trail opposite Raymond Pool.
Atlantic Marsh Fiddler Crabs
Among the Saltmarsh Cordgrass along the trail and on the banks of the tidal creek there, a visitor will find thousands and thousands of Atlantic Marsh Fiddler Crabs (Minuca pugnax).
Atlantic Marsh Fiddler Crabs
Atlantic Marsh Fiddler Crabs and their extensive system of burrows help prevent the compaction of tidal soils and thus help maintain ideal conditions for the pure stands of Saltwater Cordgrass that trap sediments and sequester nutrients in coastal wetlands.
Atlantic Marsh Fiddler Crab
A male Atlantic Marsh Fiddler Crab peers from its den.
Great Egret
Herons and egrets including this Great Egret are quite fond of fiddler crabs.  As the tide goes out, many will venture away from the freshwater pools into the salt marshes to find them.
Green Heron
A Green Heron seen just before descending into the cordgrass to find fiddler crabs for dinner.
Clapper Rail
A juvenile Clapper Rail (Rallus crepitans crepitans) emerges from the cover of the cordgrass along a tidal creek to search for a meal.
Glossy Ibis
Glossy Ibis leave their high-tide hiding place in Shearness Pool to head out into the tidal marshes for the afternoon.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide.
Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide in the marshes opposite Shearness Pool.
Ospey
An Osprey patrols the vast tidal areas opposite Shearness Pool.

No visit to Bombay Hook is complete without at least a quick loop through the upland habitats at the far end of the tour route.

Indigo Bunting
Indigo Buntings nest in areas of successional growth and yes, that is a Spotted Lanternfly on the grape vine at the far right side of the image.
Blue Grosbeak
Blue Grosbeaks (Passerina caerulea) are common nesting birds at Bombay Hook.  This one was in shrubby growth along the dike at the north end of Shearness Pool.
Trumpet Creeper and Poison Ivy
These two native vines are widespread at Bombay Hook and are an excellent source of food for birds. The orange flowers of the Trumpet Vine are a hummingbird favorite and the Poison Ivy provides berries for numerous species of wintering birds.
Pileated Woodpecker in Sweet Gum
The Pileated Woodpecker is one of the numerous birds that supplements its diet with Poison Ivy berries.  The tree this individual is visiting is an American Sweetgum (Liquidambar styraciflua), a species native to the Atlantic Coastal Plain in Delaware.  The seed balls are a favorite winter food of goldfinches and siskins.
Red-bellied Slider and Painted Turtle
Finis Pool has no frontage on the tidal marsh but is still worth a visit.  It lies along a spur road on the tour route and is located within a deciduous coastal plain forest.  Check the waters there for basking turtles like this giant Northern Red-bellied Cooter (Pseudemys rubiventris) and much smaller Painted Turtle.
White-tailed Deity
The White-tailed Deity is common along the road to Finis Pool.
Fowler's Toad
Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.
Turk's Cap Lily
The National Wildlife Refuge System not only protects animal species, it sustains rare and unusual plants as well.  This beauty is a Turk’s Cap Lily (Lilium superbum), a native wildflower of wet woods and swamps.
Wild Turkey
Just as quail led us into the refuge this morning, this Wild Turkey did us the courtesy of leading us to the way out in the afternoon.

We hope you’ve been convinced to visit Bombay Hook National Wildlife Refuge sometime soon.  And we hope too that you’ll help fund additional conservation acquisitions and improvements by visiting your local post office and buying a Federal Duck Stamp.

Hidden Surprises

If you’re like us, you’re forgoing this year’s egg hunt due to the prices, and, well, because you’re a little bit too old for such a thing.

Instead, we took a closer look at some of our wildlife photographs from earlier in the week.  We’ve learned from experience that we don’t always see the finer details through the viewfinder, so it often pays to give each shot a second glance on a full-size screen.  Here are a few of our images that contained some hidden surprises.


Blue-winged Teal and American Black Ducks
We photographed these Blue-winged Teal and American Black Ducks as they were feeding in a meadow wetland…

..but upon closer inspection we located…

Common Green Darner
…a Common Green Darner patrolling for mosquitoes and other prey.  The Common Green Darner is a migratory species of dragonfly.  After mating, they deposit their eggs in wetland pools, ponds, and slow-moving streams.

Water Strider
We photographed this Water Strider as it was “walking” across a pool in a small stream that meanders through a marshy meadow…

..but after zooming in a little closer we found…

Water Strider with a Mosquito
…a mosquito coming to deposit its eggs had been seized as a mid-day meal.   Look at how the legs of the Water Strider use the surface tension of the pool to allow it to “walk on water”, even while clutching and subduing its prey.

Canada Geese
We photographed these resident Canada Geese in a small plowed cornfield in an area managed mostly as a mix of cool-season and warm-season grassland…

..but then, following further examination, we discovered…

Ring-necked Pheasant
…a hen Ring-necked Pheasant on a nest.

THE BAD EGG

Red-winged Blackbirds
We photographed this small group of migrating Red-winged Blackbirds while it was feeding among corn stubble in a plowed field…

…but a careful search of the flock revealed…

Brown-headed Cowbirds and Red-winged Blackbirds
…three female Brown-headed Cowbirds among them (the unstreaked brown birds, two to the far left and one among the “red-wings” to the right).  Cowbirds practice nest parasitism as a means of putting their young up for adoption.  Red-winged Blackbirds and numerous other species are the unknowing victims.  The female cowbird discreetly deposits her egg(s) in the adopting party’s nest and abandons it.  The cowbird egg and the hatchling that follows is cared for by the victim species, often at the expense of their own young.

Happy Halloween

Here’s wishing you and yours a Happy Halloween.  It’s a much-anticipated day of excitement capped by surprise visits from strange-looking hideous creatures you’ve never seen before.  They don’t stop by for a chat.  Nope, not a word.  Just a little bit of nearly imperceptible buzzing when the move around.  You see, the little sneaks have hatched a plan.  They want to eat your stuff and maybe trash the place before they go.  And when you finally get rid of them, more start showing up—dozens and dozens, then hundreds.  The more you have, the more you attract.  You’ll be shocked that there are that many living in your neighborhood.  It’s like a scene from “Nightmare on Maple Street”.  The invasion drives some people mad, but you’re just going to love it.  So, get ready, because here they come.  Trick or Treat!

Brown Marmorated Stink Bug
Q:  What’s scariest thing about having Brown Marmorated Stink Bugs over for Halloween?
Brown Marmorated Stink Bug and Spotted Lanternfly
A:  They bring along their friends.

Photo of the Day

Yellowjacket Hover Fly
With today’s abundance of sunshine, the storm-related cold snap has come to an end and autumn insects were again out and about in the lower Susquehanna region.  Yellowjacket Hover Flies (Milesia virginiensis) are important pollinators, feeding on flower nectar along the edges of forests and in meadows.  These harmless mimics of yellowjacket wasps not only resemble their ill-tempered lookalikes in appearance, but they produce similar buzzy wing sounds too.  Yellowjacket Hover Flies are known colloquially as “news bees” due to their habit of lingering around people and constantly “giving them the news”.  The larvae are as beneficial as the adults, feeding on decaying plant matter in rotting wood.  Larvae of some other members of their family, the Syrphidae, feed on aphids.

Same Story, Different Ending

Once upon a time, a great panic spread throughout the lower Susquehanna region.  A destructive mob of invaders was overtaking our verdant land and was sure to decimate all in its path.  Clad in gray and butternut, they came by the thousands.  Flashing their crimson banners, they signaled their arrival at each new waypoint along their route.  The Pennsylvania government called upon the populace to heed the call and turn out in defense of the state.  Small bands of well-intentioned citizens tried in vain to turn back the progress of the hostiles—none succeeded.  But for a cadre of civic-minded elites and some small groups of college professors and their students, few responded to a call to confine the invasion along designated lines of containment.  Word spread quickly throughout the valley that farms had been overrun by waves of the merciless intruders.  Agrarians reported that their orchards had been stripped; they had lost all of the fruits of their labor.  Stories exaggerating the hideous appearance of the approaching aliens struck fear into the faint-of-heart.  The growing sentiment among the terror-stricken residents: this horde must be stopped before pestilence is visited upon everyone in the state!

And so, on the evening of June 28, 1863, just three days before the Battle of Gettysburg, the wooden Susquehanna River bridge at Columbia-Wrightsville was set ablaze just as Brigadier General John B. Gordon’s brigade of the invading Army of Northern Virginia approached the span’s west entrance preparing to cross to the eastern shore.  Thus, the rebel tide was turned away from the Susquehanna at the point some contend to be the authentic “High-water Mark of the Confederacy”.

Just one among an army of Spotted Lanternflies marching westbound across the Susquehanna River on the present-day Columbia-Wrightsville Bridge.  Same story, different ending.          

Smoky Skies in the Lower Susquehanna Region

During the coming two weeks, peak numbers of migrating Neotropical birds will be passing through the northeastern United States including the lower Susquehanna valley.  Hawk watches are staffed and observers are awaiting big flights of Broad-winged Hawks—hoping to see a thousand birds or more in a single day.

During its passage through the Lower Susquehanna River Watershed, an adult Broad-winged Hawk sails over Second Mountain Hawk Watch in Lebanon County, Pennsylvania.
A hatch-year/juvenile Broad-winged Hawk gazes toward hawk watchers on the ground.

Broad-winged hawks feed on rodents, amphibians, and a variety of large insects while on their breeding grounds in the forests of the northern United States and Canada.  They depart early, journeying to wintering areas in Central and South America before frost robs them of a reliable food supply.

The Carolina Saddlebags (Tramea carolina), this one photographed at Second Mountain Hawk Watch on September 8th, is the rarest of the lower Susquehanna region’s migratory dragonflies.  Autumn Broad-winged Hawk movements coincide with southbound flights of the Carolina Saddlebags and the more numerous migratory dragonfly species: Common Green Darner, Wandering Glider, Twelve-spotted Skimmer, and Black Saddlebags.  “Broad-wings” will often eat these and other dragonflies during migration and can sometimes be seen catching and feeding upon them while still soaring high overhead.

While migrating, Broad-winged Hawks climb to great altitudes on thermal updrafts and are notoriously difficult to see from ground level.  Bright sunny skies with no clouds to serve as a backdrop further complicate a hawk counter’s ability to spot passing birds.  Throughout the Lower Susquehanna River Watershed, the coming week promises to be especially challenging for those trying to observe and census the passage of high-flying Broad-winged Hawks.  The forecast of hot and humid weather is not so unusual, but the addition of smoke from fires in the western states promises to intensify the haze and create an especially irritating glare for those searching the skies for raptors.

Smoke from fires along the California coast and in central Utah can be seen streaming east this morning.  (NOAA/GOES image)
Smoke from western fires and humid air creates a band of haze in Ohio, Pennsylvania, New Jersey, and states to the south this morning.   (NOAA/GOES image)

 

A migrating Broad-winged Hawk in the glare of a hazy sky.  In addition to visibility problems, swarms of Spotted Lanternflies above the treetops make distant hawks difficult to discern for hawk watchers scanning the horizon with binoculars.

It may seem gloomy for the mid-September flights in 2021, but hawk watchers are hardy types.  They know that the birds won’t wait.  So if you want to see migrating “Broad-wings” and other species, you’ve got to get out there and look up while they’re passing through.

Migrating Ospreys typically fly low enough and are large enough to be spotted even during the haziest of conditions.
Bald Eagles like this fourth-year bird can ascend to great altitude, but their size usually prevents them from sneaking past a lookout unnoticed.
Peregrines escape notice not due to hazy sky conditions, but because they pass by so quickly.  They’re being seen at local hawk watches now through October.

These hawk watches in the Lower Susquehanna River Watershed are currently staffed by official counters and all welcome visitors:

    • Rocky Ridge County Park Hawk Watch—3699 Deininger Road off Mount Zion Road (Route 24) northeast of York, Pennsylvania.
    • Second Mountain Hawk Watch—off Cold Spring Road on the grounds of Fort Indiantown Gap in Lebanon County, Pennsylvania.
    • Waggoner’s Gap Hawk Watch—where Route 74 crosses Blue Mountain north of Carlisle, Pennsylvania.

—or you can just keep an eye on the sky from wherever you happen to be.  And don’t forget to check the trees and shrubs because warbler numbers are peaking too!  During recent days…

Northern Parula at Chiques Rock County Park in Lancaster County.
Black-and-white Warbler at Rocky Ridge County Park in York County.
Cape May Warbler at Chiques Rock County Park in Lancaster County.
Bay-breasted Warbler at Rocky Ridge County Park in York County.

Be on the Lookout for Mississippi Kites

Common sense tells us that Brood X Periodical Cicada emergence begins in the southern part of the population zone, where the ground temperatures reach 64° first, then progresses to the north as the weather warms.  In the forested hills where the lower Piedmont falls away onto the flat landscape of the Atlantic Coastal Plain in Maryland’s Cecil and Harford Counties, the hum of seventeen-year-old insects saturates a listener’s ears from all directions—the climax nears.

Periodical Cicadas, mostly Magicicada  septendecim, are well into their breeding cycle along the Piedmont-Atlantic Coastal Plain border right now.  Love is in the air.

With all that food flying around, you just knew something unusual was going to show up to eat it.  It’s a buffet.  It’s a smorgasbord.  It’s free, it’s all-you-can-eat, and it seems, at least for the moment, like it’s going to last forever.  You know it’ll draw a crowd.

The Mississippi Kite (Ictinia mississippiensis), a trim long-winged bird of prey, is a Neotropical migrant, an insect-eating friend of the farmer, and, as the name “kite” suggests, a buoyant flier.  It experiences no winter—breeding in the southern United States from April to July, then heading to South America for the remainder of the year.  Its diet consists mostly of large flying insects including beetles, leafhoppers, grasshoppers, dragonflies, and, you guessed it, cicadas.  Mississippi Kites frequently hunt in groups—usually catching and devouring their food while on the wing.  Pairs nest in woodlands, swamps, and in urban areas with ample prey.  They are well known for harmlessly swooping at people who happen to get too close to their nest.

Mississippi Kites nest regularly as far north as southernmost Virginia.  For at least three decades now, non-breeding second-year birds known as immatures have been noted as wanderers in the Mid-Atlantic States, particularly in late May and early June.  They are seen annually at Cape May, New Jersey.  They are rare, but usually seen at least once every year, along the Piedmont-Atlantic Coastal Plain border in northern Delaware, northeastern Maryland, and/or southeastern Pennsylvania.  Then came the Brood X Periodical Cicadas of 2021.

During the last week of May and these first days of June, there have been dozens of sightings of cicada-eating Mississippi Kites in locations along the lower Piedmont slope in Harford and Cecil Counties in Maryland, at “Bucktoe Creek Preserve” in southern Chester County, Pennsylvania, and in and near Newark in New Castle County, Delaware.  They are being seen daily right on the lower Susquehanna watershed’s doorstep.

Today, we journeyed just south of Mason’s and Dixon’s Delaware-Maryland-Pennsylvania triangle to White Clay Creek State Park along Route 896 north of Newark, Delaware.  Once there, we took a short bicycle ride into a wooded neighborhood across the street in Maryland to search for the Mississippi Kites that have been reported there in recent days.

Periodical Cicadas filled the treetops and the airspace just above them.
It wasn’t long before Mississippi Kites appeared over the trees along a hilltop clearing to snatch up cicadas for a morning meal.
This kite glides on autopilot as it holds a captured cicada in its talons and tears it apart with its hook-shaped bill.
At least ten Mississippi Kites have been seen simultaneously at this site or in nearby Newark during recent days. This morning, we saw six.
All the Mississippi Kites we saw today were second-year birds.  The banded tail is characteristic of both hatch-year (juvenile) and second-year (immature) Mississippi Kites.  Of course, at this time of year, hatch-year birds are still in the nest and not flying around pigging out on Periodical Cicadas.
The banded tail, gray underside, and white head of a second-year Mississippi Kite.  Though known as immature or subadult birds during their second year, there are records of Mississippi Kites successfully breeding at this age.  Recent wanderings into the Mid-Atlantic States and New England have led to a spotty expansion of the nesting range there.
Mississippi Kites in their second year undergo molt of their flight feathers. The timing can vary greatly among individual birds with diet among the factors affecting the process.  This bird is just beginning the replacement of its juvenile remiges and rectrices.
Tail molt beginning on this second-year Mississippi Kite.  These banded juvenile tail feathers will be replaced by a set of all-dark adult rectrices.
A second-year Mississippi Kite with an all-dark adult tail feather (rectrix).  An abundance of protein-rich cicadas should provide ample nutrition to keep the molt process going for this maturing bird, at least for another couple of weeks.  Relocating inland on the Piedmont could keep this and other kites well-nourished for even longer.

Will groups of Mississippi Kites develop a taste for our seventeen-year cicadas and move north into the Lower Susquehanna River Watershed?  Ah, to be young and a nomad—that’s the life.  Wandering on a whim with one goal in mind—food.  It could very well be that now’s the time to be on the lookout for Mississippi Kites, especially where Brood X Periodical Cicadas are abundant.

Identification of the Three Species of Brood X Periodical Cicadas

The emergence of Brood X Periodical Cicadas is now in full swing.  If you visit a forested area, you may hear the distant drone of very large concentrations of one or more of the three species that make up the Brood X event.   The increasing volume of a chorus tends to attract exponentially greater numbers of male cicadas from within an expanding radius, causing a swarm to grow larger and louder—attracting more and more females to the breeding site.

Holes in the ground where emerging Brood X Periodical Cicadas have come to the surface.
The exuvia of Periodical Cicadas that, following emergence from the soil, have ascended the trunk of an Eastern White Pine.  The exuvia is the exoskeletal remains of the cicada’s final molt from a nymph into a flying adult.

Each Periodical Cicada species has a distinctive song.  This song concentrates males of the same species at breeding sites—then draws in an abundance of females of the same species to complete the mating process.  Large gatherings of Periodical Cicadas can include all three species, but a close look at swarms on State Game Lands 145 in Lebanon County and State Game Lands 46 (Middle Creek Wildlife Management Area) in Lancaster County during recent days found marked separation by two of the three.  Most swarms were dominated by Magicicada septendecim, the largest, most widespread, and most common species.  However, nearly mono-specific swarms of M. cassinii, the second most numerous species, were found as well.  An exceptionally large one was northwest of the village of Colebrook on State Game Lands 145.  It was isolated by a tenth of a mile or more from numerous large gatherings of M. septendecim cicadas in the vicinity.  These M. cassinii cicadas, with a chorus so loud that it outdistanced the songs made by the nearby swarms of M. septendecim, seized the opportunity to separate both audibly and physically from the more dominant species, thus providing better likelihood of maximizing their breeding success.

Some of the tens of thousands of M. cassinii Periodical Cicadas in a concentration on State Game Lands 145 northwest of Colebrook in Lebanon County, Pennsylvania.  This swarm occupied deciduous and evergreen trees on several acres of a south-facing hillside.  To provide protection from predators and assure the chance of finding a mate “in the crowd”, lesser numbers of this and the rarer species, Magicicada septendecula, would need to merge into the swarms of the abundant M. septendecim Periodical Cicadas to breed.

The process of identifying Periodical Cicadas is best begun by listening to their choruses, songs, and calls.  After all, the sounds of cicadas will lead one to the locations where they are most abundant.  The two most common species, M. septendecim and M. cassinii, produce a buzzy chorus that, when consisting of hundreds or thousands of cicadas “singing” in unison, creates a droning wail that can carry for a quarter of a mile or more.  It’s a surreal humming sound that may remind one of a space ship from a science fiction film.

Listen to the songs of individual cicadas at close range and you’ll hear a difference between the widespread M. septendecim “Pharaoh Periodical Cicada” and the other two species.  M. septendecim‘s song is often characterized as a drawn out version of the word “Pharaoh”, hence the species’ unofficial common name.  As part of their courtship ritual, “Pharaoh Periodical Cicadas” sometimes make a purring or cooing sound, which is often extended to sound like kee-ow, then sometimes revved up further to pha-raohM. cassinii, often known as “Cassin’s Periodical Cicada”, and the least common species, M. septendecula, often make scratchy clicking or rattling calls as a lead-in to their song.  Most observers will find little difficulty locating the widespread M. septendecim “Pharaoh Periodical Cicada” by sound, so listening for something different—the clicking call—is an easy way to zero in on the two less common species.

To penetrate the droning choruses of large numbers of “Pharaoh” and/or “Cassin’s Periodical Cicadas”, sparingly distributed M. septendecula cicadas have a noise-penetrating song consisting of a series of quick raspy notes with a staccato rhythm reminiscent of a pulsating lawn sprinkler.   It can often be differentiated by a listener even in the presence of a roaring chorus of one or both of the commoner species.  However, a word of caution is due.  To call in others of their kind, “Cassin’s Periodical Cicadas” can produce a courtship song similar to that of M. septendecula so that they too can penetrate the choruses of the enormous numbers of “Pharaoh Periodical Cicadas” that concentrate in many areas.  To play it safe, it’s best to have a good look at the cicadas you’re trying to identify.

M. cassinii Periodical Cicadas “singing” from a treetop at Colebrook, Lebanon County, Pennsylvania.  Clicking phrases are sure sign of the presence of this species and/or M. septendecula, the least likely of the three species to be encountered.  When in close proximity to a swarm, a listener will often notice the rising and falling volume of a chorus in a cycle that repeats every few seconds, an effect caused by cicadas attempting to synchronize their songs in a harmony with others in the group.  When courtship and mating is complete, female Periodical Cicadas will begin laying eggs in slits made in fresh new growth at the ends of branches on deciduous trees like the one seen here.

Visually identifying Brood X Periodical Cicadas to the species level is best done by looking for two key field marks—first, the presence or absence of orange between the eye and the root of the wings, and second, the presence or absence of orange bands on the underside of the abdomen.  Seeing these field marks clearly requires in-hand examination of the cicada in question.

Observing a perched Brood X Periodical Cicada can sometimes provide a view of the key field marks needed for identification of the species.  On the M. septendecim “Pharaoh Periodical Cicada” seen here, the orange patch between the eye and wing root and the orange bands on the underside of the abdomen are visible.
The abdomen of this perched M. cassinii “Cassin’s Periodical Cicada” appears, when viewed through the wings, to have orange bands.  But, examination in hand would show an all-black abdomen with glossy surfaces shining in the sunlight.  For accuracy, the up-close-and-personal look is necessary.
In the hand, cicadas can be better studied for key field marks.  M. septendecim (top) is larger than M. cassini (bottom) and M. septendecula, but the difference is not always apparent, particularly when a direct comparison cannot be made.

To reliably separate Brood X Periodical Cicadas by species, it is necessary to get a closeup view of the section of the thorax between the eye and the root (insertion) of the wings, plus a look at the underside of the abdomen.  Here’s what you’ll see…

Magicicada septendecim—“Pharaoh Periodical Cicada”

M. septendecim has an orange patch between the eye and the root of the wings.
The underside of M. septendecim’s abdomen has orange bands or stripes along the trailing edge of each segment. The width of the bands can vary, but is typically wider on males (left) than on females (right).

Magicicada cassinii—“Cassin’s Periodical Cicada”

The thorax of M. cassinii is black between the eye and the wing insertion.
The underside of M. cassinii’s abdomen is all black without orange bands or stripes in both the male (left) and female (right).

Magicicada septendecula

M. septendecula’s thorax is black between the eye and root of the wings.
The underside of M. septendecula’s abdomen has narrow orange bands or stripes along the trailing edge of each segment.  The width of the bands can differ.  Those of this male (left) are minimal and the bands on this female (right) are near the maximum for the species.

There you have it.  Get out and take a closer look at the Brood X Periodical Cicadas near you.

The abundant and widespread “Pharaoh Periodical Cicada” (M. septendecim).
It’ll all be over before long.  Accumulating remains of M. cassinii “Cassin’s Periodical Cicadas” beneath an Eastern White Pine at the site of the Colebrook State Game Lands swarm.

They’re Here

The Magi have arrived.   Emanating from the shadows of a nearby forest, you may hear the endless drone of what sounds like an extraterrestrial craft.  Then you get your first look at those beady red eyes set against a full suit of black armor—out of this world.  The Magicicada are here at last.

This exuvia, the leftover from a cicada’s final molt, tells us they are here.
A Brood X Periodical Cicada soon after emergence and final molt.
Not to worry, cicadas are harmless and docile when handled.  This is Magicicada septendecim, the largest and most common of our three species of Brood X seventeen-year cicadas.  They are currently emerging along south-facing borders of forests and wooded parks and lawns.
Magicicada septendecim can be recognized by the orange on the thorax behind each eye and in front of the wing insertions.  The smaller M. cassinii and M. septendecula have no orange coloration between the eye and wing.
Magicicada septendecim (seen here) has broad orange stripes on the abdomen.  M. cassinii has an all black abdomen and M. septendecula, the rarest species, has narrow well-defined orange stripes.

If you go out and about to observe Periodical Cicadas, keep an eye open for these species too…

Spotted Lanternflies, one of our most dreaded invasive species, have hatched.  These tiny nymphs about 5 millimetres in length were found feeding on a Virginia Creeper (Parthenocissus quinquefolia), a native vine in the grape family (Vitaceae).
Deer Ticks, also known as Black-legged Ticks, are hanging around on vegetation of all kinds looking to hitch a ride on a suitable host.  Don’t let it be you.  This adult female, less than 5 millimetres in length, was washed loose during an after-hike shower.

Seventeen Years Ago Today

Back in the spring of 2004, members of the Tri-County Conewago Creek Association (T.C.C.C.A.), a non-profit conservation group founded to improve water quality in Conewago Creek and its tributaries in Dauphin, Lancaster, and Lebanon Counties in Pennsylvania, were, in order to better understand the status of the flora and fauna in the watershed, frequently spending their weekends surveying the animal and plant life found in the drainage basin’s forests, streams, and farmlands.  This effort identified populations of several species of concern and helped supplement the more formal assessment that was used to determine the placement, scale, and scope of projects needed to reduce nutrient and erosion impairment in the Conewago’s waterways.

These regular outings happened to coincide with the Brood X Periodical Cicada emergence of 2004.  Back then, as the record keeper for the T.C.C.C.A.’s weekly survey forays, your editor decided to shade a map of the Conewago Creek Watershed showing where the group’s volunteers encountered choruses of the Brood X cicadas.  Fortunately, the map is still in the editor’s pile of stuff, and is reproduced here for you.

T.C.C.C.A.’s brochure map of the Conewago Creek Watershed (the Conewago east of the Susquehanna River), shaded with red ink in 2004 indicating locations where noisy choruses of Brood X Periodical Cicadas were found.  The range of the insects closely mirrors the forested areas of the watershed.  The nearly contiguous range along the southeast border includes the heavily wooded areas of Mount Gretna, State Game Lands 145, and the northwest slope of the diabase ridge that separates the Conewago from neighboring watersheds in Lancaster County.

A notation on the map (visible just above the cap on the pen) indicates May 16 as the emergence date for the cicadas in 2004—seventeen years ago today.

So why no seventeen-year cicadas yet in 2021?  The answer is ground temperature.  This year, by mid-April, Brood X Periodical Cicadas were just below the leaves and rocks, ready to break the surface.  But a cold month since then has stalled their emergence.  A thermometer pushed into the forest soil today showed readings of 60 degrees and less—at least four degrees below the temperature needed to get the nymphs crawling out of the dirt to climb rocks and vegetation where they’ll molt, dry, and take flight.

In the forested hills east of Conewago Falls, in the Conewago Creek Watershed, soil temperatures were as low as 54 degrees Fahrenheit today.

A warm week ahead with daytime temperatures in the eighties and nighttime lows in the fifties and sixties, instead of in the forties, should get the woodland soils warming.  Brood X Periodical Cicadas will be out and about in a jiffy—and you’ll hear all about it.

Coming up, The Great Eastern Brood.

Coming Soon, Very Soon: Brood X Periodical Cicadas

Yesterday, a hike through a peaceful ridgetop woods in the Furnace Hills of southern Lebanon County resulted in an interesting discovery.  It was extraordinarily quiet for a mid-April afternoon.  Bird life was sparse—just a pair of nesting White-breasted Nuthatches and a drumming Hairy Woodpecker.  A few deer scurried down the hillside.  There was little else to see or hear.  But if one were to have a look below the forest floor, they’d find out where the action is.

Not much action in the deer-browsed understory of this stand of hardwoods.
Upon discovery beneath a rock, this invertebrate quickly backed its way down the burrow, promptly seeking shelter in the underground section of the excavation.
A closeup of the same image reveals the red eyes of this Periodical Cicada (Magicicada species) nymph.  It has reached the end of seventeen years of slowly feeding upon the sap from a tree root to nourish its five instars (stages) of larval development.

2021 is an emergence year for Brood X, the “Great Eastern Brood”—the largest of the 15 surviving broods of Periodical Cicadas.  After seventeen years as subterranean larvae, the nymphs are presently positioned just below ground level, and they’re ready to see sunlight.  After tunneling upward from the deciduous tree roots from which they fed on small amounts of sap since 2004, they’re awaiting a steady ground temperature of about 64 degrees Fahrenheit before surfacing to climb a tree, shrub, or other object and undergo one last molt into an imago—a flying adult.

Here, approximately one dozen Periodical Cicada nymphs have tunneled into pre-emergence positions beneath a rock.  Seventeen-year Periodical Cicadas, sometimes mistakenly called “seventeen-year locusts”, are the longest-lived of our insects.
Note the wings and red eyes beneath the exoskeleton of this Periodical Cicada nymph. Within weeks it will join billions of others in a brief emergence to molt, dry, fly, mate, and die.
Adult (imago) Periodical Cicadas.  Brood X includes all three species of seventeen-year Periodical Cicadas: Magicicada septendecim, M. cassinii, and M. septendecula.  All Periodical Cicadas in the United States are found east of the Great Plains, the lack of trees there prohibiting the expansion of their range further west.  Seventeen-year life cycles account for twelve of the fifteen broods of Periodical Cicadas; the balance live for thirteen years.  The range of Brood X includes the lower Susquehanna basin and parts of Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, Ohio, Tennessee, Virginia, West Virginia, and the District of Columbia.  (United States Department of Agriculture/Agricultural Research Service image)
The flight of Periodical Cicadas peaks in late-May and June.  Shown here is the Eastern Scissor Grinder, an “Annual Cicada” that emerges later in the season, peaking yearly during July and August.

The woodlots of the Lower Susquehanna River Watershed won’t be quiet for long.  Loud choruses of male Periodical Cicadas will soon roar through forest and verdant suburbia.  They’re looking for love, and they’re gonna die trying to find it.  And dozens and dozens of animal species will take advantage of the swarms to feed themselves and their young.  Yep, the woods are gonna be a lively place real soon.

Did you say Periodical Cicadas?  We can hardly wait!

Forest vs. Woodlot

Let’s take a quiet stroll through the forest to have a look around.  The spring awakening is underway and it’s a marvelous thing to behold.  You may think it a bit odd, but during this walk we’re not going to spend all of our time gazing up into the trees.  Instead, we’re going to investigate the happenings at ground level—life on the forest floor.

Rotting logs and leaf litter create the moisture retaining detritus in which mesic forest plants grow and thrive.  Note the presence of mosses and a vernal pool in this damp section of forest.
The earliest green leaves in the forest are often those of the Skunk Cabbage (Simplocarpus foetidus).  This member of the arum family gets a head start by growing in the warm waters of a spring seep or in a stream-fed wetland.  Like many native wildflowers of the forest, Skunk Cabbage takes advantage of early-springtime sun to flower and grow prior to the time in late April when deciduous trees grow foliage and cast shade beneath their canopy.
Among the bark of dead and downed trees, the Mourning Cloak butterfly (Nymphalis antiopa) hibernates for the winter.  It emerges to alight on sun-drenched surfaces in late winter and early spring.
Another hibernating forest butterfly that emerges on sunny early-spring days is the Eastern Comma (Polygonia comma), also known as the Hop Merchant.
In a small forest brook, a water strider (Gerridae) chases its shadow using the surface tension of the water to provide buoyancy.  Forests are essential for the protection of headwaters areas where our streams get their start.
Often flooded only in the springtime, fish-free pools of water known as vernal ponds are essential breeding habitat for many forest-dwelling amphibians.  Unfortunately, these ephemeral wetland sites often fall prey to collecting, dumping, filling, and vandalism by motorized and non-motorized off-roaders, sometimes resulting in the elimination of the populations of frogs, toads, and salamanders that use them.
Wood Frogs (Lithobates sylvaticus) emerge from hiding places among downed timber and leaf litter to journey to a nearby vernal pond where they begin calling still more Wood Frogs to the breeding site.
Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the pond dries up in the summertime.  It’s a risky means of reproduction, but it effectively evades the enormous appetites of fish.
When the egg laying is complete, adult Wood Frogs return to the forest and are seldom seen during the rest of the year.
In early spring, Painted Turtles emerge from hideouts in larger forest pools, particularly those in wooded swamps, to bask in sunny locations.
Dead standing trees, often called snags, are essential habitats for many species of forest wildlife.  There is an entire biological process, a micro-ecosystem, involved in the decay of a dead tree.  It includes fungi, bacteria, and various invertebrate animals that reduce wood into the detritus that nourishes and hydrates new forest growth.
Birds like this Red-headed Woodpecker feed on insects found in large snags and nest almost exclusively in them.  Many species of wildlife rely on dead trees, both standing and fallen, during all or part of their lives.

There certainly is more to a forest than the living trees.  If you’re hiking through a grove of timber getting snared in a maze of prickly Multiflora Rose (Rosa multiflora) and seeing little else but maybe a wild ungulate or two, then you’re in a has-been forest.  Logging, firewood collection, fragmentation, and other man-made disturbances inside and near forests take a collective toll on their composition, eventually turning them to mere woodlots.  Go enjoy the forests of the lower Susquehanna valley while you still can.  And remember to do it gently; we’re losing quality as well as quantity right now—so tread softly.

The White-tailed Deity in a woodlot infested by invasive tangles of Multiflora Rose.

Some Autumn Insects

With autumn coming to a close, let’s have a look at some of the fascinating insects (and a spider) that put on a show during some mild afternoons in the late months of 2019.

Bush Katydids (Scudderia species) are found in brushy habitats and along rural roadsides.  Their green summer color fades to brown, maroon, and gold to match the autumn foliage where they hide.  Bush katydids often remain active until a hard freeze finally does them in.
The Eastern Buck Moth (Hemileuca maia) is fuzzy, appearing to wear a warm coat for its autumn expeditions.  Adults emerge in October and may fly as late as December.  Females deposit their eggs on the twigs of Bear Oak (Quercus ilicifolia), Blackjack Oak (Q. marilandica), or Chestnut Oak (Q. montana), trees that, in our region, seem most favorable for the moth’s use when growing on burned barrens and mountain slopes.  The spiny caterpillars are known to feed only on the foliage of these few trees.  In the lower Susquehanna valley, the Eastern Buck Moth is rare because its specialized habitat is in short supply, and it’s all Smokey The Bear’s fault.
The Sachem (Atalopedes campestris) wanders north from the Atlantic Coastal Plain into the Susquehanna valley each summer.  In some years they become the most numerous small orange butterfly of all, particularly around home gardens.  The larvae will feed on Crabgrass (Digitaria species), but have not found success overwintering this far north.  By November, adults begin to look pretty drab.
From 1978 through 1982, the Asian Multicolored Lady Beetle (Harmonia axyridis) was introduced into the eastern states by the United States Department of Agriculture.  It has become a nuisance in many areas where it swarms, sometimes bites, and often overwinters in large smelly masses within homes and other warm buildings.  As you may have guessed, it’s possibly displacing some of the less aggressive native lady beetle species.
On a chilly afternoon, a sun-warmed Bold Jumping Spider (Phidippus audax) pounced and dispatched this sluggish worker Honey Bee (Apis mellifera) that was trying to gather pollen from a late-season Purple Coneflower bloom.  This spider is bold indeed.
Under bridges, inside bird nest boxes, and sometimes beneath porches, the female Pipe Organ Mud Dauber (Trypoxylon politum), a predatory wasp, builds these elaborate nests composed of long rows (pipes) of nursery cells.  Into each cell one or more paralyzed spiders is deposited along with one of the female’s eggs.  When hatched, each larva will feed upon the paralyzed spider(s) inside its cell, then pupate.  The pupae overwinter, then emerge from their cells as adults during the following spring.  In the autumn, males often stand guard at an entrance to the nest to prevent parasitic species, including some flies (look at the fifth pipe from the right), from laying eggs on the pupae.  These wasps are not aggressive toward humans.
A Black-and-yellow Mud Dauber (Sceliphron caementarium) observes a neighboring nest of Common Paper Wasps (Polistes exclamans).  The Common Paper Wasp, a species also known as the Guinea Paper Wasp, is a native of the southern United States.  It is currently expanding its range into the lower Susquehanna valley from the Atlantic Coastal Plain.  These two wasp species and the Pipe Organ Mud Dauber are known to regularly coexist.  All three will take advantage of man-made structures for their nest sites.  People using the picnic tables beneath this pavilion roof never noticed the hundreds of docile wasps above.
Those moody Eastern Yellowjackets (Vespula maculifrons) can get very temperamental during warm autumn days.  These wasps may appear to have no enemies, but away from areas impacted by man’s everyday activities, they do.  The Robber Fly (Promachus species) hunts like a flycatcher or other woodland bird, waiting on a perch along the forest’s edge for prey to pass by, then ambushing it, yellowjackets included.
The invasive Spotted Lanternfly, a native of eastern Asia, continues to spread destruction.  It established itself throughout much of the east side of the lower Susquehanna River during the summer and fall of 2019.  Their route of travel across the farmlands of the region intersects with plenty of vineyards to obliterate and few, if any, natural enemies.  Expect them to begin colonizing the west shore en masse during 2020.
In 2020, plan to roll a few Spotted Lanternflies over, enjoy the view, and wait for the crimson tide to pass.  With any luck, they’ll peak in a year or two.

SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York, NY.

Spotted Lanternfly in the Lower Susquehanna River Watershed

Second Mountain Hawk Watch is located on a ridge top along the northern edge of the Fort Indiantown Gap Military Reservation and the southern edge of State Game Lands 211 in Lebanon County, Pennsylvania.  The valley on the north side of the ridge, also known as St. Anthony’s Wilderness, is drained to the Susquehanna by Stony Creek.  The valley to the south is drained toward the river by Indiantown Run, a tributary of Swatara Creek.

The hawk watch is able to operate at this prime location for observing the autumn migration of birds, butterflies, dragonflies, and bats through the courtesy of the Pennsylvania Game Commission and the Garrison Commander at Fort Indiantown Gap.  The Second Mountain Hawk Watch Association is a non-profit organization that staffs the count site daily throughout the season and reports data to the North American Hawk Watch Association (posted daily at hawkcount.org).

Today, Second Mountain Hawk Watch was populated by observers who enjoyed today’s break in the rainy weather with a visit to the lookout to see what birds might be on the move.  All were anxiously awaiting a big flight of Broad-winged Hawks, a forest-dwelling Neotropical species that often travels back to its wintering grounds in groups exceeding one hundred birds.  Each autumn, many inland hawk watches in the northeast experience at least one day in mid-September with a Broad-winged Hawk count exceeding 1,000 birds.  They are an early-season migrant and today’s southeast winds ahead of the remnants of Hurricane Florence (currently in the Carolinas) could push southwest-heading “Broad-wings” out of the Piedmont Province and into the Ridge and Valley Province for a pass by the Second Mountain lookout.

The flight turned out to be steady through the day with over three hundred Broad-winged Hawks sighted.  The largest group consisted of several dozen birds.  We would hope there are probably many more yet to come after the Florence rains pass through the northeast and out to sea by mid-week.  Also seen today were Bald Eagles, Ospreys, American Kestrels, and a migrating Red-headed Woodpecker.

Migrating Broad-winged Hawks circle on a thermal updraft above Second Mountain Hawk Watch to gain altitude before gliding away to the southwest.

Migrating insects included Monarch butterflies, and the three commonest species of migratory dragonflies: Wandering Glider, Black Saddlebags, and Common Green Darner.  The Common Green Darners swarmed the lookout by the dozens late in the afternoon and attracted a couple of American Kestrels, which had apparently set down from a day of migration.  American Kestrels and Broad-winged Hawks feed upon dragonflies and often migrate in tandem with them for at least a portion of their journey.

Still later, as the last of the Broad-winged Hawks descended from great heights and began passing by just above the trees looking for a place to settle down, a most unwelcome visitor arrived at the lookout.  It glided in from the St. Anthony’s Wilderness side of the ridge on showy crimson-red wings, then became nearly indiscernible from gray tree bark when it landed on a limb.  It was the dreaded and potentially invasive Spotted Lanternfly (Lycorma delicatula).  This large leafhopper is native to Asia and was first discovered in North America in the Oley Valley of eastern Berks County, Pennsylvania in 2014.  The larval stage is exceptionally damaging to cultivated grape and orchard crops.  It poses a threat to forest trees as well.  Despite efforts to contain the species through quarantine and other methods, it’s obviously spreading quickly.  Here on the Second Mountain lookout, we know that wind has a huge influence on the movement of birds and insects.  The east and southeast winds we’ve experienced for nearly a week may be carrying Spotted Lanternflies well out of their most recent range and into the forests of the Ridge and Valley Province.  We do know for certain that the Spotted Lanternfly has found its way into the Lower Susquehanna River Watershed.

This adult Spotted Lanternfly landed in a birch tree behind the observers at the Second Mountain Hawk Watch late this afternoon.  It was first recognized by its bright red wings as it glided from treetops on the north side of the lookout.

Noxious Benefactor

It’s sprayed with herbicides.  It’s mowed and mangled.  It’s ground to shreds with noisy weed-trimmers.  It’s scorned and maligned.  It’s been targeted for elimination by some governments because it’s undesirable and “noxious”.  And it has that four letter word in its name which dooms the fate of any plant that possesses it.   It’s the Common Milkweed, and it’s the center of activity in my garden at this time of year.  Yep, I said milk-WEED.

Now, you need to understand that my garden is small—less than 2,500 square feet.  There is no lawn, and there will be no lawn.  I’ll have nothing to do with the lawn nonsense.  Those of you who know me, know that the lawn, or anything that looks like lawn, and I are through.

Anyway, most of the plants in the garden are native species.  There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed.  The unusually wet growing season in 2018 has been very kind to these plants.  They are still very green and lush.  And the animals that rely on them are having a banner year.  Have a look…

The flowers of the Common Milkweed were exceptionally fragrant this year.  At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into the house and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from my walls (100 feet from his).
Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species).  The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases.  Are you following this?  Remember as we proceed, milkweed is noxious.
Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.
A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.
Following the pollination of the flowers, seed pods will begin to grow.  I trim these off the plants.  The removal of the extra weight allows most of the stems to remain erect through stormy weather.  You’ll still get new plants from underground runners.  As you may have guessed, I’m trying to keep these plants upright and strong to host Monarch butterfly larvae.

I’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects.  This year, these plants are exceptionally colorful for late-August due to the abundance of rain.  The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.

Big Bluestem, a native warm-season grass in flower.
Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower.  This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the  herd animals and fires of the prairie to prevent succession and allow it to thrive.
Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.
Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.
Indiangrass (Sorghastrum nutans) in flower.  This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA).  They have an unbelievably large selection of indigenous species.  You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.
A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea).  Yes, it is that Echinacea.

There was Monarch activity in the garden today like I’ve never seen before—and it revolved around milkweed and the companion plants.

A female Monarch laying eggs on a Common Milkweed leaf.
A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf.  Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.
Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf.  There were over thirty of these caterpillars in just a ten by ten feet area this morning.  I hope if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!
A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.
Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant.  Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle.  Need more milkweed!
After benefitting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.
Two hours later, the chrysalis is complete.
Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one.  An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.
There it is, soon ready to fly away.  And all courtesy of the noxious milkweed.
A chrysalis can often be found on man-made objects too.  This one is on the rim of a flower pot.
Ornamental flowers can attract adult Monarch butterflies seeking nectar.  I am now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides.  There’s growing concern over the impact these compounds may be having on pollinating species of animals.  Oh…and I don’t mow, whack, cut, mutilate, or spray herbicides on my milkweed  But you probably figured that out already.

 SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York.

The Dungeon

There’s something frightening going on down there.  In the sand, beneath the plants on the shoreline, there’s a pile of soil next to a hole it’s been digging.  Now, it’s dragging something toward the tunnel it made.  What does it have?  Is that alive?

We know how the system works, the food chain that is.  The small stuff is eaten by the progressively bigger things, and there are fewer of the latter than there are of the former, thus the whole network keeps operating long-term.  Some things chew plants, others devour animals whole or in part, and then there are those, like us, that do both.  In the natural ecosystem, predators keep the numerous little critters from getting out of control and decimating certain other plant or animal populations and wrecking the whole business.  When man brings an invasive and potentially destructive species to a new area, occasionally we’re fortunate enough to have a native species adapt and begin to keep the invader under control by eating it.  It maintains the balance.  It’s easy enough to understand.

Japanese Beetles (Popillia japonica) seen here on Halberd-leaved Rose Mallow.  Without predation, exploding numbers of this invasive non-indigenous insect can defoliate and kill numerous species of plants in a given area.
The Song Sparrow (Melospiza melodia) is a generalist feeder, eating seeds and invertebrates including Japanese Beetles.  This species is the omnipresent year-round occupant of shoreline vegetation along the lower Susquehanna River.

Late summer days are marked by a change in the sounds coming from the forests surrounding the falls.  For birds, breeding season is ending, so the males cease their chorus of songs and insects take over the musical duties.  The buzzing calls of male “Annual Cicadas” (Neotibicen species) are the most familiar.  The female “Annual Cicada” lays her eggs in the twigs of trees.  After hatching, the nymphs drop to the ground and burrow into the soil to live and feed along tree roots for the next two to five years.  A dry exoskeleton clinging to a tree trunk is evidence that a nymph has emerged from its subterranean haunts and flown away as an adult to breed and soon thereafter die.  Flights of adult “Annual Cicadas” occur every year, but never come anywhere close to reaching the enormous numbers of “Periodical Cicadas” (Magicicada species).  The three species of “Periodical Cicadas” synchronize their life cycles throughout their combined regional populations to create broods that emerge as spectacular flights once every 13 or 17 years.

An “Annual Cicada” also known as a “Dog-day Cicada”, clings to the stem of a Halberd-leaved Rose Mallow at Conewago Falls.

For the adult cicada, there is danger, and that danger resembles an enormous bee.  It’s an Eastern Cicada Killer (Specius speciosus) wasp, and it will latch onto a cicada and begin stinging while both are in flight.  The stings soon paralyze the screeching, panicked cicada.  The Cicada Killer then begins the task of airlifting and/or dragging its victim to the lair it has prepared.  The cicada is placed in one of more than a dozen cells in the tunnel complex where it will serve as food for the wasp’s larvae.  The wasp lays an egg on the cicada, then leaves and pushes the hole closed.  The egg hatches in a several days and the larval grub is on its own to feast upon the hapless cicada.

An Eastern Cicada Killer (Sphecius speciosus) along the river shoreline. Despite their intimidating appearance, they do not sting humans and can be quite docile when approached.

Other species in the Solitary Wasp family (Sphecidae) have similar life cycles using specific prey which they incapacitate to serve as sustenance for their larvae.

A Solitary Wasp, one of the Thread-waisted Wasps (Ammophila species), drags a paralyzed moth caterpillar to its breeding dungeon in the sandy soil at Conewago Falls.  For the victim, there is no escape from the crypt.

The Solitary Wasps are an important control on the populations of their respective prey.  Additionally, the wasp’s bizarre life cycle ensures a greater survival rate for its own offspring by providing sufficient food for each of its progeny before the egg beginning its life is ever put in place.  It’s complete family planning.

The cicadas reproduce quickly and, as a species, seem to endure the assault by Cicada Killers, birds, and other predators.  The Periodical Cicadas (Magicicada), with adult flights occurring as a massive swarm of an entire population every thirteen or seventeen years, survive as species by providing predators with so ample a supply of food that most of the adults go unmolested to complete reproduction.  Stay tuned, 2021 is due to be the next Periodical Cicada year in the vicinity of Conewago Falls.

SOURCES

Eaton, Eric R., and Kenn Kaufman.  2007.  Kaufman Field Guide to Insects of North America.  Houghton Mifflin Company.  New York.