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!)

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.

Underwater View of Life in a Vernal Pool

It may look like just a puddle in the woods, but this is a very specialized wetland habitat, a habitat that is quickly disappearing from the Lower Susquehanna River Watershed.  It’s a vernal pool—also known as a vernal pond or an ephemeral (lasting a short time) pool or pond.

Viable vernal pools have several traits in common…

      • They contain water in the spring (hence the name vernal).
      • They have no permanent inflow or outflow of water.
      • They typically dry up during part of the year—usually in late summer.
      • They are fish-free.
      • They provide breeding habitat for certain indicator species of forest-dwelling amphibians and other animals.
      • They are surrounded by forest habitat that supports the amphibians and other vernal pool species during the terrestrial portion of their life cycle.

To have a closer look at what is presently living in this “black leaf” vernal pool, we’re calling on the crew of the S. S. Haldeman to go down under and investigate.

Along the surface of the pool we’re seeing clusters of amphibian eggs, a sign that this pond has been visited by breeding adult frogs and/or salamanders during recent weeks.
Amphibian eggs and the white tail filaments of an invertebrate of interest, Springtime Fairy Shrimp (Eubranchipus vernalis), an endemic of vernal ponds.

Let’s take it down for a better look.  Dive, all dive!

Algae provides food for the shrimp and other inhabitants of the pool.  Leaf litter furnishes hiding places for the pool’s many inhabitants.
These loose clusters of eggs appears to be those of Wood Frogs, a vernal pool indicator species.
Clusters of Wood Frog eggs, the embryos within those in the center of the image less developed than those to the left.
More Wood Frog eggs.  Hatching can take anywhere from two weeks to two months, depending on temperature.
Wood Frog eggs with developing larvae (tadpoles) plainly visible.  The green color of the eggs is created by a symbiotic algae, Oophila amblystomatis, a species unique to vernal pools.  The algae utilizes the waste produced by the developing embryos to fuel its growth and in return releases oxygen into the water during photosynthesis.  Upon hatching, the tadpoles rely upon the algae as one of their principle food sources.
A zoomed-in view showing development of the larvae and what appears to be a tiny invertebrate clinging on the white egg in the upper right.  White eggs don’t hatch and may be infected by a fungus.
Wood Frog eggs and Springtime Fairy Shrimp.
Wood Frog eggs and Springtime Fairy Shrimp.
Springtime Fairy Shrimp swim upside-down.  Note the small, bluish clusters of eggs attached to the abdomens of these females.  Springtime Fairy Shrimp live their entire lives in the vernal pool.  After being deposited in the debris at the bottom of the pool, the eggs will dry out during the summer, then freeze and re-hydrate before hatching during the late winter.
A damselfly larva consuming fairy shrimp.  (Visible in the margin between the uppermost lobes of the dark-colored oak leaf to the right.)
Getting in close we see A) the damselfly larva eating a Springtime Fairy Shrimp and B) one of several discarded exoskeletons of consumed shrimp near this predator.
A fishfly larva (Chauliodinae).  Mosquito numbers are kept in check by the abundance of predators in these pools.
Springtime Fairy Shrimp and a Marbled Salamander (Ambystoma opacum) larva.  The presence of these species confirms this small body of water is a fully-functioning vernal pool.
Springtime Fairy Shrimp and two more larval Marbled Salamanders.  The salamanders’ enlarged gills are necessary to extract sufficient oxygen from the still waters of the pool.
The Marbled Salamander is one of three species of mole salamanders found in the Lower Susquehanna River Watershed.  All breed in vernal pools and live their air-breathing adult lives under the leaves of the forest in subterranean tunnels where they feed on worms and other invertebrates.  Photos of an adult Marbled Salamander and the other two species, Spotted Salamander (Ambystoma maculatum) and Jefferson Salamander (Ambystoma jeffersonianum), can be found by clicking the “Amphibians” tab at the top of this page.
Marbled Salamanders lay their eggs during the fall.  If the bed of the pool is dry at breeding time, the adult female will remain to guard the eggs until rain floods the pool.  The eggs hatch upon inundation, sometimes during the winter.
Marbled Salamanders, like all amphibians that develop in vernal pools, must complete transformation into their air-breathing terrestrial life stage before the pool dries up in the summer heat.
A larval Marbled Salamander explores the bottom of the pool.
A larval Marbled Salamander, Wood Frog eggs, and Springtime Fairy Shrimp, it’s an abundance of life in what at first glance may appear to be just a mud puddle.

We hope you enjoyed this quick look at life in a vernal pool.  While the crew of the S. S. Haldeman decontaminates the vessel (we always scrub and disinfect the ship before moving between bodies of water) and prepares for its next voyage, you can learn more about vernal pools and the forest ecosystems of which they are such a vital component.  Be sure to check out…

If you are a landowner or a land manager, you can find materials specifically providing guidance for protecting, restoring, and re-establishing vernal pool habitats at…

Wood Frogs mating
Wasted Effort-A pair of Wood Frogs mating in a dried-up vernal pool.

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.

Photo of the Day

The shade-loving Shadow Darner (Aeshna umbrosa) is a common species of resident dragonfly in the lower Susquehanna basin.  Females deposit their eggs on aquatic vegetation in clean still waters, including those found in marshy sections of streams, beaver ponds, and even, on occasion, garden pools, as long as they aren’t overpopulated with large fish.  Shadow Darners are the most likely of the dragonflies to be noticed cruising in search of prey at dusk and are the last to be seen during the season, sometimes still found hawking small insects on warm days in November.  As you may have guessed, they are quite fond of consuming mosquitoes.

Warblers Passing Through the Lower Susquehanna River Valley

Neotropical birds are presently migrating south from breeding habitats in the United States and Canada to wintering grounds in Central and South America.  Among them are more than two dozen species of warblers—colorful little passerines that can often be seen darting from branch to branch in the treetops as they feed on insects during stopovers in the Lower Susquehanna River Watershed.

Being nocturnal migrants, warblers are best seen first thing in the morning among sunlit foliage, often high in the forest canopy.  After a night of flying, they stop to feed and rest.  Warblers frequently join resident chickadees, titmice, and nuthatches to form a foraging flock that can contain dozens of songbirds.  Migratory flycatchers, vireos, tanagers, and grosbeaks often accompany southbound warblers during early morning “fallouts”.  Usually, the best way to find these early fall migrants is to visit a forest edge or thicket, particularly along a stream, a utility right-of-way, or on a ridge top.  Then too, warblers and other Neotropical migrants are notorious for showing up in groves of mature trees in urban parks and residential neighborhoods—so look up!

A Black-and-white Warbler descends into the tangles of the forest understory to search for a morning meal of insects or creepy-crawlies.
Success!  Looks like a cranefly (Tipulidae).
A Black-throated Green Warbler high in the treetops.
Warblers often travel and feed in the company of other Neotropical species like this Red-eyed Vireo.
Get out and look for those Neotropical migrants now because, like this Canada Warbler, in just a few weeks they’ll be gone.

Be sure to visit the Birds of Conewago Falls page by clicking the “Birds” tab at the top of this page.  There, you’ll find photographs of the birds, including warblers and other Neotropical migrants, that you’re likely to encounter at locations throughout the Lower Susquehanna River Watershed.

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.

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.

They Call Me the Wanderer

It’s been an atypical summer.  The lower Susquehanna River valley has been in a cycle of heavy rains for over a month and stream flooding has been a recurring event.  At Conewago Falls, the Pothole Rocks have been inundated for weeks.  The location used as a lookout for the Autumn Migration Count last fall is at the moment submerged in ten feet of roaring water.  Any attempt to tally the migrants which are passing thru in 2018 will thus be delayed indefinitely.  Of greater import, the flooding at Conewago Falls is impacting many of the animals and plants there at a critical time in their annual life cycle.  Having been displaced from its usual breeding sites on the river, one insect species in particular seems to be omnipresent in upland areas right now, and few people have ever heard of it.

So, you take a cruise in the motorcar to your favorite store and arrive at the sprawling parking lot.  Not wishing to have your doors dented or paint chipped because you settled for a space tightly packed among other shopper’s conveyances, you park out there in the “boondocks”.  You know the place, the lightly-used portion of the lot where sometimes brush grows from cracks in the asphalt and you must be on alert for impatient consumers who throttle-up to high speeds and dash diagonally across the carefully painted grids on the pavement to reach their favorite parking destination in the front row.  Coming to a stop, you take the car out of gear, set the brake, disengage the safety belt, and gather your shopping list.  You grasp the door handle and, not wanting to be flattened  by one of the aforementioned motorists, you have a look around before exiting.

It was then that you saw the thing, hovering above your shiny bright hood.  For a brief moment, it seemed to be peering right through the windshield at you with big reddish-brown eyes.  In just a second or two, it turned its whole bronze body ninety degrees to the left and darted away on its cellophane wings.  Maybe you didn’t really get a good look at it.  It was so fast.  But it certainly was odd.  Oh well, time to walk inside a grab a few provisions.  Away you go.

Upon completion of your shopping, you’re taking the long stroll back to your car and you notice more of these peculiar creatures.  Two are coupled together and are hovering above someone’s automobile hood, then they drop down, and the lower of the two taps its abdomen on the paint.  You ask yourself, “What are these bizarre things?”

Meet the Wandering Glider (Pantala flavescens), also known as the Globe Wanderer or Globe Skimmer, a wide-ranging dragonfly known to occur on every continent with the exception of Antarctica.

Wandering Gliders sometimes arrive in the lower Susquehanna River valley in large numbers after catching a ride on sustained winds from southerly directions and will often fly and migrate in storm systems.  Conditions for such movements have been optimal in our region since mid-July.  These dragonflies will often hover above motor vehicle hoods and, after mating, females will deposit eggs upon them, apparently mistaking their glossy surface for small pools of water.

Wandering Gliders travel the globe, and as such are accomplished fliers.  Adults spend most of the day on the wing, feeding upon a variety of flying insects.  Days ago, I watched several intercepting a swarm of flying ants.  As fast as ants left the ground they were grabbed and devoured by the gliders.  Wandering Gliders are adept at taking day-flying mosquitos, often zipping stealthily past a person’s head or shoulders to grab one of the little pests—the would-be skeeter victim usually unaware of the whole affair.

Due to their nomadic life history, Wandering Gliders are opportunists when breeding and will lay eggs in most any body of freshwater.  Their larvae do not overwinter prior to maturity; adults can be expected in a little more than one to two months.  Repetitive flooding in the Lower Susquehanna River Watershed this summer may be reducing the availability of the best local breeding sites for this species—riverine, stream, and floodplain pools of standing water with prey.  This may explain why thousands of Wandering Gliders are patrolling parking lots, farmlands, and urban areas this summer.  And it’s the likely reason for their use of puddles on asphalt pavement, on rubber roofs, and in fields as places to try to deposit eggs.  Unfortunately, they may be as likely to succeed there as they are on your motor vehicle hood.

At this time a year ago, the airspace above the Diabase Pothole Rocks at Conewago Falls was jammed with territorial male Wandering Gliders.  Each male hovered at various locations around his breeding territory consisting of pools and water-filled potholes.  Intruders would quickly be dispatched from the area, then the male would resume his patrols from a set of repetitively-used hovering positions about six feet above the rocks.  Mating and egg-laying continued into late September.  The larvae, also called nymphs or naiads, were readily observed in many pools and potholes in early October and the emergence of juveniles was noted in mid-October.  The absence of flooding, the mild autumn weather, and the moderation of water temperatures in the pools and potholes courtesy of the sun-drenched diabase boulders helped to extend the 2017 breeding season for Wandering Gliders in Conewago Falls.  They aren’t likely to experience the same favor this year, but their great ability to travel and adapt should overcome this momentary misfortune.

A male Wandering Glider aggressively patrols his territory in the Diabase Pothole Rocks Microhabitat at Conewago Falls.  August 20, 2017.
A mating pair of Wandering Gliders continue flying non-stop above one of thousands of suitable breeding pools among the Diabase Pothole Rocks at Conewago Falls.  September 23, 2017.
A female (bottom)Wandering Glider has deposited eggs in a pool while flying in tandem with a male (top).  They’ll do the same thing on your automobile hood!  Conewago Falls Diabase Pothole Rocks Microhabitat.  September 23, 2017.
Wandering Glider larvae are at the top of the food chain in flooded potholes.  As they grew, these dragonfly larvae decimated the mosquito larvae which were abundant there earlier in the summer.  October 7, 2017.
A juvenile male Wandering Glider emerges from the pool where it fed and grew as a larva.  It remained at water’s edge on the surface of a sun-warmed diabase rock for several hours to dry its wings.  It soon flew away to parts unknown, possibly traveling hundreds or thousands of miles.  Look carefully at the wings for the beige dash marks on the forward edge near the terminal end.  Females lack this marking.  Conewago Falls Diabase Pothole Rocks Microhabitat.  October 14, 2017.
A Wandering Glider exuviae, the shed exoskeleton of a creature gone, but not forgotten.  October 14, 2017.

 

Shocking Fish Photos!

There are two Conewago Creek systems in the Lower Susquehanna River Watershed.  One drains the Gettysburg Basin west of the river, mostly in Adams and York Counties, then flows into the Susquehanna at the base of Conewago Falls.  The other drains the Gettysburg Basin east of the river, flowing through Triassic redbeds of the Gettysburg Formation and York Haven Diabase before entering Conewago Falls near the south tip of Three Mile Island.  Both Conewago Creeks flow through suburbia, farm, and forest.  Both have their capacity to support aquatic life impaired and diminished by nutrient and sediment pollution.

This week, some of the many partners engaged in a long-term collaboration to restore the east shore’s Conewago Creek met to have a look at one of the prime indicators of overall stream habitat health—the fishes.  Kristen Kyler of the Lower Susquehanna Initiative organized the effort.  Portable backpack-mounted electrofishing units and nets were used by crews to capture, identify, and count the native and non-native fishes at sampling locations which have remained constant since prior to the numerous stream improvement projects which began more than ten years ago.  Some of the present-day sample sites were first used following Hurricane Agnes in 1972 by Stambaugh and Denoncourt and pre-date any implementation of sediment and nutrient mitigation practices like cover crops, no-till farming, field terracing, stormwater control, nutrient management, wetland restoration, streambank fencing, renewed forested stream buffers, or modernized wastewater treatment plants.  By comparing more recent surveys with this baseline data, it may be possible to discern trends in fish populations resulting not only from conservation practices, but from many other variables which may impact the Conewago Creek Warmwater Stream ecosystem in Dauphin, Lancaster, and Lebanon Counties.

So here they are.  Enjoy these shocking fish photos.

Matt Kofroth, Watershed Specialist with the Lancaster County Conservation District, operates the electrofishing wand in Conewago Creek while his team members prepare to net and collect momentarily-stunned fish.  Three other electrofishing units operated by staff from the Susquehanna River Basin Commission and aided by teams of netters were in action at other sample locations along the Conewago on this day.
Really big fish, such as this Common Carp (Cyprinus carpio), were identified, counted, and immediately returned to the water downstream of the advancing electrofishing team.  Koi of the garden pond are a familiar variety of Common Carp, a native of Asia.
Other fish, such as the Swallowtail Shiner, Redbreast Sunfish (Lepomis auritus), Fallfish, and suckers seen here,  were placed in a sorting tank.
Fallfish (Semotilus corporalis) are very active and require plenty of dissolved oxygen in the water to survive.  Fallfish, Rainbow Trout (Oncorhynchus mykiss), and Smallmouth Bass (Micropterus dolomieu) were quickly identified and removed from the sorting tank for release back into the stream.  Other larger, but less active fish, including suckers, quickly followed.
Small fish like minnows were removed from the sorting tank for a closer look in a hand-held viewing tank.  This Fathead Minnow (Pimephales promelas) was identified, added to the tally sheet, and released back into the Conewago.  The Fathead Minnow is not native to the Susquehanna drainage.  It is the minnow most frequently sold as bait by vendors.
A breeding condition male Bluntnose Minnow (Pimephales notatus).
The Cutlips Minnow (Exoglossum maxillingua) is a resident of clear rocky streams.  Of the more than 30 species collected during the day, two native species which are classified as intolerant of persisting stream impairment were found: Cutlips Minnow and Swallowtail Shiner.
This young River Chub (Nocomis micropogon) is losing its side stripe.  It will be at least twice as large at adulthood.
The Eastern Blacknose Dace (Rhinichthys atratulus) is found in clear water over pebble and stone substrate..
The Longnose Dace (Rhinichthys cataractae) is another species of pebbly rocky streams.
A juvenile Golden Shiner (Notemigonus crysoleucas).  Adults lack the side stripe and grow to the size of a sunfish.
A Swallowtail Shiner (Notropis procne) and a very young White Sucker (Catostomus commersonii) in the upper left of the tank.
A Spotfin Shiner (Cyprinella spiloptera).
A breeding male Spotfin Shiner.  Show-off!
The Margined Madtom (Noturus insignis) is a small native catfish of pebbly streams.
The Banded Killifish (Fundulus diaphanus) is adept at feeding upon insects, including mosquitos.
A young Rock Bass (Ambloplites rupestris).  This species was introduced to the Susquehanna and its tributaries.
The Greenside Darter (Etheostoma blennioides) is not native to the Susquehanna basin.  The species colonized the Conewago Creek (east) from introduced local populations within the last five years.
The Tessellated Darter (Etheostoma olmstedi) is a native inhabitant of the Susquehanna and its tributaries.
The stars of the day were the American Eels (Anguilla rostrata).
After collection, each eel was measured and weighed using a scale and dry bucket.  This specimen checked in at 20 inches and one pound before being released.
Prior to the construction of large dams, American Eels were plentiful in the Susquehanna and its tributaries, including the Conewago.  They’ve since been rarities for more than half a century.  Now they’re getting a lift.
American Eels serve as an intermediate host for the microscopic parasitic glochidia (larvae) of the Eastern Elliptio (Elliptio complanata), a declining native freshwater mussel of the Lower Susquehanna River Watershed.  While feeding on their host (usually in its gills), the glochidia cause little injury and soon drop off to continue growth, often having assured distribution of their species by accepting the free ride.  Freshwater mussels are filter feeders and improve water quality.  They grow slowly and can live for decades.
American Eels are a catadromous species, starting life as tiny glass eels in the saltwater of the Atlantic Ocean, then migrating to tidal brackish marshes and streams (males) or freshwater streams (females) to mature.  This 20-incher probably attempted to ascend the Susquehanna as an elver in 2016 or 2017.  After hitching a ride with some friendly folks, she bypassed the three largest dams on the lower Susquehanna (Conowingo, Holtwood, and Safe Harbor) and arrived in the Conewago where she may remain and grow for ten years or more.  To spawn, a perilous and terminally fatal journey to the Sargasso Sea awaits her.  (You may better know the area of the Sargasso Sea as The Bermuda Triangle…a perilous place to travel indeed!)

SOURCES

Normandeau Associates,  Inc. and Gomez and Sullivan.  2018.  Muddy Run Pumped Storage Project Conowingo Eel Collection Facility FERC Project 2355.  Prepared for Exelon.

Stambaugh, Jr., John W., and Robert P. Denoncourt.  1974.  A Preliminary Report on the Conewago Creek Faunal Survey, Lancaster County, Pennsylvania.  Proceedings of the Pennsylvania Academy of Sciences.  48: 55-60.

The Antagonist

They can be a pesky nuisance.  The annoying high-frequency buzzing is bad enough, but it’s the quiet ones that get you.  While you were swatting at the noisy one, the silent gender sticks you and begins to feed.  Maybe you know it, or maybe you don’t.   She could make you itch and scratch.  If she’s carrying a blood-borne pathogen, you could get sick and possibly die.

To humans, mosquitos are the most dangerous animal in the world (though not in the United States where man himself and the domestic dog are more of a threat).  Globally, the Anopheles mosquitos that spread Malaria have been responsible for millions and millions of human deaths.  Some areas of Africa are void of human habitation due to the prevalence of Malaria-spreading Anopheles mosquitos.  In the northeastern United States, the Northern House Mosquito (Culex pipiens), as the carrier of West Nile Virus, is the species of greatest concern.  Around human habitations, standing water in tires, gutters, and debris are favorite breeding areas.  Dumping stagnant water helps prevent the rapid reproduction of this mosquito.

In recent years, the global distribution of these mosquito-borne illnesses has been one of man’s inadvertent accomplishments.  An infected human is the source of pathogens which the feeding mosquito transmits to another unsuspecting victim.  Infectious humans, traveling the globe, have spread some of these diseases to new areas or reintroduced them to sectors of the world where they were thought to have been eliminated.  Additionally, where the specific mosquito carrier of a disease is absent, the mobility of man and his cargos has found a way to transport them there.  Aedes aegypti, the “Yellow Fever Mosquito”, carrier of its namesake and the Zeka Virus, has found passage to much of the world including the southern United States.  Unlike other species, Aedes aegypti dwells inside human habitationsthus transmitting disease rapidly from person to person.  Another non-native species, the Asian Tiger Mosquito (Aedes albopictus), vector of Dengue Fever in the tropics, arrived in Houston in 1985 in shipments of used tires from Japan and in Los Angeles in 2001 in wet containers of “lucky bamboo” from Taiwan…some luck.

Asian Tiger Mosquito in action during the daylight hours, typical behavior of the genus. This species has been found in the area of Conewago Falls since at least 2013.

Poor mosquito, despite the death, suffering, and misery it has brought to Homo sapiens and other species around the planet, it will never be the most destructive animal on earth.  You, my bloodthirsty friends, will place second at best.  You see, mosquitos get no respect, even if they do create great wildlife sanctuaries by scaring people away.

The winner knows how to wipe out other species and environs not only to ensure its own survival, but, in many of its populations, to provide leisure, luxury, gluttony, and amusement.  This species possesses the cognitive ability to think and reason.  It can contemplate its own existence and the concepts of time.  It is aware of its history, the present, and its future, though its optimism about the latter may be its greatest delusion.  Despite possessing intellect and a capacity to empathize, it is devious, sinister, and selfish in its treatment of nearly every other living thing around it.  Its numbers expand and its consumption increases.  It travels the world carrying pest and disease to all its corners.  It pollutes the water, land, and air.  It has developed language, culture, and social hierarchies which create myths and superstitions to subdue the free will of its masses.   Ignoring the gift of insight to evaluate the future, it continues to reproduce without regard for a means of sustenance.  It is the ultimate organism, however, its numbers will overwhelm its resources.  The crowning distinction will be the extinction.

Homo sapiens will be the first animal to cause a mass extinction of life on earth.  The forces of nature and the cosmos need to wait their turn; man will take care of the species annihilation this time around.  The plants, animals, and clean environment necessary for a prosperous healthy life will cease to exist.  In the end, humans will degenerate, live in anguish, and leave no progeny.  Fate will do to man what he has done to his co-inhabitants of the planet.

The Bald Eagle (Haliaeetus leucocephalus) is again a breeding species in the Susquehanna River watershed.  It is generally believed that during the mid-twentieth century, Dichlorodiphenyltrichloroethane (DDT) pesticide residues accumulated in female top-of-the-food-chain birds including Bald Eagles.  As a result, thinner egg shells were produced.  These shells usually cracked during incubation, leading to failed reproduction in entire populations of birds, particularly those that fed upon fish or waterfowl.  In much of the developed world, DDT was used liberally during the mid-twentieth century to combat Malaria by killing mosquitos.  It was widely used throughout the United States as a general insecticide until it was banned here in 1972.  (Editors Note:  There is the possibility that polychlorinated biphenyls [P.C.B.s] and other industrial pollutants contributed to the reproductive failure of birds at the apex of aquatic food chains.  Just prior to the recovery of these troubled species, passage of the Clean Water Act in 1972 initiated reductions in toxic discharges from point sources into streams, rivers, lakes, bays, and oceans.  Production of P.C.B.s was banned in the United States in 1978.  Today, P.C.B.s from former discharge and dumping sites continue to be found in water.  Spills can still occur from sources including old electric transformers.)
To substitute any other beast would be folly.  Man, the human, Homo sapiens, the winner and champion, will repeatedly avail himself as the antagonist during our examination of the wonders of wildlife.  He is the villain.  The tragedy of his self-proclaimed dominion over the living things of the world will wash across these pages like muddy water topping a dam.  There’s nothing I can do about it, aside from fabricating a bad novel with a fictional characterization of man.  So let’s get on with it and take a look at “A Natural History of Conewago Falls”.  Let’s discover the protagonist, the heroic underdog of our story, “Life in the Lower Susquehanna River Watershed.”

Over the top today.
SOURCES

Avery, Dennis T.  1995.  Saving the Planet with Pesticides and Plastic: The Environmental Triumph of High-Yield Farming.  Hudson Institute.  Indianapolis, Indiana.

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

Newman, L.H.  1965.  Man and Insects.  The Natural History Press.  Garden City, New York.