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.
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.
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.
You might not hurt a fly, but plenty of other creatures will. This Greenbottle Fly relies upon speed and maneuverability to quickly flee predators.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 an unarmed Honey Bee mimic. This one is gathering nectar on goldenrod flowers.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.Flower flies of the genus Spilomyia are convincing mimics of temperamental yellowjacket wasps.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?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. Like other mimics of hymenopterans, they are important pollinators of flowering plants.This hover fly of the genus Syrphus is another wasp mimic.
TACHINID FLIES
The Feather-legged Fly (Trichopoda species) is a wasp mimic. Its larvae are parasitoids of stink bugs and leaf-footed bugs.
BEE FLIES
Bee flies of the genus Exoprosopa convincingly resemble bumble bees.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!
With nearly all of the Neotropical migrants including Broad-winged Hawks gone for the year, observers and counters at eastern hawk watches are busy tallying numbers of the more hardy species of diurnal raptors and other birds. The majority of species now coming through will spend the winter months in temperate and sub-tropical areas of the southern United States and Mexico.
Here is a quick look at the raptors seen this week at two regional counting stations: Kiptopeke Hawk Watch near Cape Charles, Virginia, and Second Mountain Hawk Watch at Fort Indiantown Gap, Pennsylvania.
The hawk-watching platform at Kiptopeke State Park is located along Chesapeake Bay near the southern tip of Delmarva Peninsula. In autumn, thousands of raptors and other birds migrate through the Atlantic Coastal Plain Province. Those that follow the shorelines south frequently concentrate in spectacular numbers before crossing the mouths of the bays they encounter. This phenomenon makes both Cape May, New Jersey, on Delaware Bay and Kiptopeke, Virginia, on Chesapeake Bay exceptional places to experience fall flights of migrating birds.A Sharp-shinned Hawk is counted as it swoops by the owl decoy at Second Mountain Hawk Watch at Fort Indiantown Gap Military Reservation. Migrating raptors save energy by riding updrafts of air created by winds blowing against the slopes of the mountainsides in the Ridge and Valley Province.A Sharp-shinned Hawk passes the lookout at Second Mountain Hawk Watch. “Sharp-shins” are currently the most numerous migrants both on the coast and at inland counting stations.A Sharp-shinned Hawk nearly passes observers unnoticed as it skims the treetops.A Sharp-shinned Hawk eyes up an owl decoy. Under cover of darkness, nocturnal owls could rather easily prey upon young and small adult hawks and falcons, both on the nest or at roost. Accordingly, many diurnal raptors instinctively harass owls to drive them from their presence. An owl decoy at the lookout helps attract migrating birds for a closer look.An adult Cooper’s Hawk flaps its way past a counting station. Like the similar Sharp-shinned Hawk, the larger Cooper’s Hawk is a member of the genus Accipiter. As a proportion of the annual fall Accipiter flight, the Cooper’s Hawk is more numerous at coastal hawk watches than at inland sites.The majority of Osprey migrate along the coast, but a few are still being seen at inland hawk watches.Bald Eagles are commonly seen at both coastal and inland lookouts. Their movements continue well into late fall.A Northern Harrier illuminated by a setting sun. Northern Harriers are often still flying when many other species have gone to roost for the day.An adult male Northern Harrier, the “gray ghost”, flying in misty weather, at a time when few other birds were in the air. The American Kestrel, like our other falcons, is seen in greatest concentrations at coastal counting stations. It is our most numerous falcon.The Merlin provides only a brief observation opportunity as it passes the lookout. These falcons are dark, speedy, and easily missed as they fly by.While moving south, Merlins often accompany flights of migrating Tree Swallows, a potential food source.A Merlin consumes a dragonfly. Eating is no reason to stop moving.The “Tundra Peregrine” is an arctic-breeding Peregrine Falcon that travels a distance of over 6,000 miles to southern South America for winter. It is strictly a migratory species in our region with numbers peaking during the first two weeks of October each year. These strong fliers have little need for the updrafts from mountain ridges, inland birds often observed flying in a north to south direction. The majority of “Tundra Peregrines” are observed following coastlines, with some migrating offshore to make landfall at points as far south as Florida and the Caribbean islands before continuing across water again to reach the northern shores of Central and South America. This “Tundra Peregrine” is a juvenile bird on its first southbound trip.
During coming days, fewer and fewer of these birds will be counted at our local hawk watches. Soon, the larger raptors—Red-tailed Hawks, Red-shouldered Hawks, and Golden Eagles—will be thrilling observers. Cooler weather will bring several flights of these spectacular species. Why not plan a visit to a lookout near you? Click on the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page for site information and a photo guide to identification. See you at the hawk watch!
It’s not all hawks at the hawk watch. Even the coastal sites are now seeing fun birds like the playful Common Raven on a regular basis.Coastal locations are renowned places to see migrating songbirds in places outside of their typical habitat. Here a flock of Eastern Meadowlarks has set down in the top of a Loblolly Pine (Pinus taeda) in downtown Cape Charles, Virginia, not far from Kiptopeke Hawk Watch.
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
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 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. Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.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 (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.A Black-and-yellow Mud Dauber at 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 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) collecting nectar and pollen on White Snakeroot (Ageratina altissima).Sweat Bees (Lasioglossum species) visit human skin to lick up the electrolytes left behind by evaporating perspiration.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.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). Sweat bees nest in subterranean cavities and in hollowed out sections of trees.A copper-colored Augochlorine Green Sweat Bee (Augochlorini) collecting nectar and dusted with pollen.
LEAFCUTTER AND MASON BEES
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) 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.A Leafcutter Bee (Megachile species) collecting nectar from White Snakeroot.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.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
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.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.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.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 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.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.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) 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) 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
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.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 (Scolia bicincta) parasitizes beetle larvae as hosts for its larvae. For carbohydrates it relishes flower nectar.
PAPER WASPS
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.A Northern Paper Wasp (Polistes fuscatus) feeding on nectar from a goldenrod flower.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.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.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 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.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.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 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.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.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.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 (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 paper nest in a tree cavity.
POTTER WASPS
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) 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.
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.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.
Tropical Storm Ophelia has put the brakes on a bustling southbound exodus of the season’s final waves of Neotropical migrants. Winds from easterly directions have now beset the Mid-Atlantic States with gloomy skies, chilly temperatures, and periods of rain for an entire week. These conditions, which are less than favorable for undertaking flights of any significant distance, have compelled many birds to remain in place—grounded to conserve energy.
In the days prior to the arrival of Tropical Storm Ophelia, thousands of high-flying Broad-winged Hawks were being tallied as they passed hawk-counting stations throughout the region. As the last of this year’s migrants continue through, lack of clear skies, sunshine, and thermal updrafts has slowed the pace of their movements significantly.
Of the birds on layover, perhaps the most interesting find has been a western raptor that occurs only on rare occasions among the groups of Broad-winged Hawks seen at hawk watches each fall—a Swainson’s Hawk. Discovered as Tropical Storm Ophelia approached on September 21st, this juvenile bird has found refuge in coal country on a small farm in a picturesque valley between converging ridges in southern Northumberland County, Pennsylvania. Swainson’s Hawks are a gregarious species, often spending time outside of the nesting season in the company of others of their kind. Like Broad-winged Hawks, they frequently assemble into large groups while migrating.
A juvenile Swainson’s Hawk in Northumberland County, Pennsylvania.
Swainson’s Hawks nest in the grasslands, prairies, and deserts of western North America. Their autumn migration to wintering grounds in Argentina covers a distance of up to 6,000 miles. Among raptors, such mileage is outdone only by the Tundra Peregrine Falcon.
The Swainson’s Hawk spends up to four months each year covering a 12,000-mile round-trip migration route. The long primaries are an adaptation that give the wings additional lift, allowing them to use air currents including thermal updrafts to conserve energy while flying.
Swainson’s Hawks are renowned for spending time on the ground, intermittently running and hopping in pursuit of prey.
During the nesting cycle, Swainson’s Hawks consume primarily small vertebrates, mostly mice and other small rodents. But during the remainder of the year, they feed almost exclusively on grasshoppers. To provide enough energy to fuel their migrations, they must find and devour these insects by the hundreds. Not surprisingly, the Swainson’s Hawk is sometimes known as the Grasshopper Hawk or Locust Hawk, particularly in the areas of South America where they are common.
The juvenile Swainson’s Hawk visiting Northumberland County has been feeding on grasshoppers, katydids, and is seen here eating a cricket.
So just how far will our wayward Swainson’s Hawk have to travel to get back on track? Small numbers of Swainson’s Hawks pass the winter in southern Florida each year and still others are found in and near the scrublands of the Lower Rio Grande Valley in Texas and Mexico. But the vast majority of these birds make the trip all the way to the southern half of South America and the farmlands and savannas of Argentina—where our winter is their summer. The best bet for this bird would be to get hooked up with some of the season’s last Broad-winged Hawks when they start flying in coming days, then join them as they head toward Houston, Texas, to make the southward turn down the coast of the Gulf of Mexico into Central America and Amazonia. Then again, it may need to find its own way to warmer climes. Upon reaching at least the Gulf Coastal Plain, our visitor stands a much better chance of surviving the winter.
As long as it can still find grasshoppers to eat, our wayward bird in Northumberland County still has time before it needs to make its way south. As they pass through Texas, Mexico, Costa Rica, and Panama, Swainson’s Hawks are numerous among flocks of southbound Broad-winged Hawks. But while hawk watches in these areas are presently recording maximum annual counts of the latter, peak numbers of the former won’t occur until the final two or three weeks of October.
They look amazingly similar to the green leaves on a deciduous tree. During the late summer and autumn, they spend their time as adults in the cover of the forest canopy. They prefer to run and hop rather than fly. But despite their discretion, you’re not likely to miss the Common True Katydid (Pterophylla camellifolia).
The Common True Katydid, also known as the Northern True Katydid, has no trouble at all hiding among the leaves.
Take a listen and you may hear the male’s nocturnal calls filling the treetops of woodlands and shady neighborhoods throughout the lower Susquehanna valley right now. The loud, raspy “ka-ty-did, she-did, she-didn’t” is reliably answered by other nearby males as competition for willing females reaches a frenzy. In mature forests where populations are dense, this rowdy chorus can reach a remarkable volume.
A mated female Common True Katydid inserts her ovipositor into a timber crevice to place her eggs in a protected location for winter.
The Common True Katydid’s song is like a soundtrack for the oft times melancholy mood of autumn. As the days shorten and a chill fills the air, the rate of the Common True Katydid’s call becomes slower and its tone deeper in response to the falling temperatures. Males continue forcing a sluggish call until freezing conditions finally bring about their demise. Another generation and another season gone.
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
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.The Carolina Grasshopper is variable in color, ranging from very dark brown……to a rich tan or khaki shade. These earth-tone colors provide the insect with effective camouflage while spending time on the ground.The Carolina Grasshopper is most readily detected and identified when it flies. The colors of the wings resemble those of the Mourning Cloak butterfly.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 with small “fairy wings”.An adult female Differential Grasshopper with fully developed wings.An adult female Differential Grasshopper
TWO-STRIPED GRASSHOPPER
Melanoplus bivittatus
An early-stage Two-striped Grasshopper nymph.A Two-striped Grasshopper nymph in a later stage.An adult female 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.An adult female Two-striped Grasshopper.
RED-LEGGED GRASSHOPPER
Melanoplus femurrubrum
An adult male Red-legged Grasshopper hiding in dense urban vegetation.The Red-legged Grasshopper may currently be our most abundant and widespread species.An adult male 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.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 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.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.
The calls of Fall Field Crickets, a series of chirps one might attempt to replicate by quickly strumming three to five teeth on a hair comb, are a familiar chorus during the late summer and autumn in the Lower Susquehanna River Watershed. The song’s speed changes with temperature, becoming noticeably slower as cold weather sets in. These crickets sing throughout the majority of the day and night, becoming quietest during the chilly hours of dawn. Adults hide in burrows and beneath logs, leaf litter, and other organic debris. Around human habitation, they seek shelter under hundreds of different objects, frequently finding their way into buildings where they do no real harm. Crickets are eaten by almost every predator that exceeds them in size and are especially important as a protein-rich food source for birds feeding their young and preparing for autumn migration. The Fall Field Cricket (Gryllus pennsylvanicus) is nearly identical in appearance to the less common Spring Field Cricket (Gryllus veletis), which calls during the spring and early summer in the Susquehanna valley. The primary difference between the two species? The former overwinter as eggs while the latter pass the colder months as nymphs.
The Gray Comma is a strikingly colorful late-summer butterfly of rich forests in the Lower Susquehanna River Watershed. It’s sure to catch your attention,……or is it?
Check out this and other local species by clicking the “Butterflies” tab at the top of this page.
To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis). They first constructed their dam on this small stream about five years ago. Since then, a flourishing wetland has become established. Have a look.
Vegetation surrounding the inundated floodplain helps sequester nutrients and sediments to purify the water while also providing excellent wildlife habitat.The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.A male Common Whitetail dragonfly keeping watch over his territory.A Twelve-spotted Skimmer perched on Soft Rush.A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).A Spicebush Swallowtail visiting a Cardinal Flower.A Green Heron looking for small fish, crayfish, frogs, and tadpoles.The Green Heron stalking potential prey.A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.A Solitary Sandpiper.A Solitary Sandpiper testing the waters for proper feeding depth.A Pectoral Sandpiper searches for its next morsel of sustenance.The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers. Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.
Isn’t that amazing? North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems. Want to clean up the streams and floodplains of your local watershed? Let the beavers do the job!
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.
The Broad-necked Root Borer (Prionus laticollis) is one of the Lower Susquehanna River Watershed’s largest insects. Its larvae feed on woody roots for more than two years before pupating and thereafter emerging as adult beetles. The distribution of root borers is not totally random. They are often attracted to distressed trees and shrubs. This particular specimen was found along a forest road where herbicide application, soil dehydration, and a recent wildfire has weakened and killed numerous oaks, poplars, and maples. As they feed, root borer larvae will help begin the process of reducing the remains of these trees into soil nutrients that will benefit regeneration of forest plants at this site.
Looking for a native wildflower that’s tall, showy, and a great choice for attracting wildlife, especially butterflies and bees? Then check out Wild Senna (Senna hebecarpa).
Wild Senna currently blooming in a roadside wildflower garden on Pennsylvania State Game Lands.
Wild Senna, also known as American Senna, is a host plant for the larvae of Cloudless Sulphur and Sleepy Orange (Eurema nicippe) butterflies. It thrives in almost any moist, well-drained soil in habitats including open woodlands, forest edges, meadows, and gardens like yours. Its height at flowering ranges from three to six feet. If you prefer, this perennial wildflower can even be cultivated as a shrub-like form. It is easily grown from seed, which is available from Ernst Conservation Seeds of Meadville, Pennsylvania, as well as numerous other vendors. And don’t forget to give Wild Senna’s two close relatives, Partridge Pea and Maryland Senna, a try as well. They attract the same species of butterflies and are just as easy to grow. You’ll like ’em.
Cloudless Sulphur butterflies from populations in the south colonize the Lower Susquehanna River Watershed each summer in varying numbers.Close-up view of a Wild Senna flower cluster. Typical of members of the pea family, the seeds of all native Senna species develop within pods after blooming and are sought after by wildfowl (Galliformes), particularly Northern Bobwhite.Partridge Pea with flowers and seed pods in the susquehannawildlife.net garden. Smaller than the other Senna species, Partridge Pea reaches a height of just two to three feet.
Your best bet for finding migrating shorebirds in the lower Susquehanna region is certainly a visit to a sandbar or mudflat in the river. The Conejohela Flats off Washington Boro just south of Columbia is a renowned location. Some man-made lakes including the one at Middle Creek Wildlife Management Area are purposely drawn down during the weeks of fall migration to provide exposed mud and silt for feeding and resting sandpipers and plovers. But with the Susquehanna running high due to recent rains and the cost of fuel trending high as well, maybe you want to stay closer to home to do your observing.
Fortunately for us, migratory shorebirds will drop in on almost any biologically active pool of shallow water and mud that they happen to find. This includes flooded portions of fields, construction sites, and especially stormwater retention basins. We stopped by a new basin just west of Hershey, Pennsylvania, and found more than two dozen shorebirds feeding and loafing there. We took each of these photographs from the sidewalk paralleling the south shore of the pool, thus never flushing or disturbing a single bird.
Designed to prevent stream flooding and pollution, this recently installed stormwater retention basin along US 322 west of Hershey, Pennsylvania, has already attracted a variety of migrating plovers and sandpipers.Killdeer stick close to exposed mud as they feed.Two of more than a dozen Least Sandpipers found busily feeding in the inch-deep water.A Lesser Yellowlegs searching for small invertebrates.Two Lesser Yellowlegs work out a disagreement.Male Twelve-spotted Skimmers patrol the airspace above a pair of Least Sandpipers. Dragonflies and other aquatic insects are quick to colonize the waters held in well-engineered retention basins. Proper construction and establishment of a functioning food chain/web in these man-made wetlands prevents them from becoming merely temporary cesspools for breeding mosquitos.
So don’t just drive by those big puddles, stop and have a look. You never know what you might find.
A Semipalmated Sandpiper (middle right) joins a flock of Least Sandpipers.Pectoral Sandpipers (two birds in the center) are regular fall migrants on the Susquehanna at this time of year. They are most frequently seen on gravel and sand bars adjacent to the river’s grassy islands, but unusually high water for this time of year prevents them from using this favored habitat. As a result, you might be lucky enough to discover Pectoral Sandpipers on almost any mudflat in the area.Two Pectoral Sandpipers and five smaller, but otherwise very similar, Least Sandpipers.A Killdeer (right), a Semipalmated Plover (upper right), and Least and Pectoral Sandpipers (left).
An ever-vigilant male Blue Dasher (Pachydiplax longipennis) perches on a small twig overlooking the vegetated shallows along the shoreline of Memorial Lake in Lebanon County, Pennsylvania.
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.
If you’re feeling the need to see summertime butterflies and their numbers just don’t seem to be what they used to be in your garden, then plan an afternoon visit to the Boyd Big Tree Preserve along Fishing Creek Valley Road (PA 443) just east of U.S. 22/322 and the Susquehanna River north of Harrisburg. The Pennsylvania Department of Conservation and Natural Resources manages the park’s 1,025 acres mostly as forested land with more than ten miles of trails. While located predominately on the north slope of Blue Mountain, a portion of the preserve straddles the crest of the ridge to include the upper reaches of the southern exposure.
A grove of American Chestnuts (Castanea dentata) planted at Boyd Big Tree Preserve is part of a propagation program working to restore blight-resistant trees to Pennsylvania and other areas of their former range which included the Appalachians and the upper Ohio River watershed.
Fortunately, one need not take a strenuous hike up Blue Mountain to observe butterflies. Open space along the park’s quarter-mile-long entrance road is maintained as a rolling meadow of wildflowers and cool-season grasses that provide nectar for adult butterflies and host plants for their larvae.
A view looking north at the butterfly meadow and entrance road at Boyd Big Tree Preserve Conservation Area. Second Mountain is in the background.Mowed paths follow the entrance road and a portion of the perimeter of the meadow allowing visitors a chance to wander among the waist-high growth to see butterflies, birds, and blooming plants at close range without trampling the vegetation or risking exposure to ticks.A Silver-spotted Skipper feeding on nectar from the flowers of Indian Hemp (Apocynum cannabinum). Like the milkweeds, Indian Hemp is a member of the dogbane family (Apocynaceae).An Eastern Tiger Swallowtail feeding on Common Milkweed.A Great Spangled Fritillary (Speyeria cybele) on Common Milkweed.A Black Swallowtail (Papilio polyxenes) feeding on Common Milkweed nectar.A Pipevine Swallowtail (Battus philenor) on Common Milkweed.Another Pipevine Swallowtail on Common Milkweed. Note the hook-shaped row of red-orange spots on the underside of the hindwing.A Pipevine Swallowtail visiting the brilliant blooms of Butterfly Weed, a favorite of a wide variety of pollinators.A Black Swallowtail with damaged wings alights atop a Butterfly Weed flower cluster. Note the pair of parallel rows of red-orange spot on the underside of the hindwing.A Monarch feeding on nectar from the flowers of Butterfly Weed.A mating pair of Eastern Tailed Blues on a Timothy (Phleum pratense) spike.A male Great Spangled Fritillary (right) pursuing a female.Butterflies aren’t the only colorful insects patrolling the meadows at Boyd Big Tree Preserve. Dragonflies including Common Green Darners are busily pursuing prey, particularly small flying insects like mosquitos, gnats, and flies.Dragonflies themselves can become prey and are much sought after by Broad-winged Hawks. This very vocal juvenile gave us several good looks as it ventured from the forest into the skies above the upper meadow during midday. It wasn’t yet a good enough flier to snag a dragonfly, but it will have plenty of opportunities for practice during its upcoming fall migration which, for these Neotropical raptors, will get underway later this month.
Do yourself a favor and take a trip to the Boyd Big Tree Preserve Conservation Area. Who knows? It might actually inspire you to convert that lawn or other mowed space into much-needed butterfly/pollinator habitat.
While you’re out, you can identify your sightings using our photographic guide—Butterflies of the Lower Susquehanna River Watershed—by clicking the “Butterflies” tab at the top this page. And while you’re at it, you can brush up on your hawk identification skills ahead of the upcoming migration by clicking the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab. Therein you’ll find a listing and descriptions of hawk watch locations in and around the lower Susquehanna region. Plan to visit one or more this autumn!
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.
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.
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.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.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 stream into Raymond Pool to escape the rising tide in the salt marsh.More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.Two more Short-billed Dowitchers on the way in.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.More Short-billed Dowitchers arriving to feed in Raymond Pool.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.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 wading to feed in the unusually high waters of Raymond Pool.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.Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.American Avocets probe the muddy bottom of Raymond Pool.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.This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.Lesser Yellowlegs at Bear Swamp Pool.Lesser Yellowlegs at Bear Swamp PoolA Greater Yellowlegs at Bear Swamp Pool.A Caspian Tern patrolling Raymond Pool.The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.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.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 Blackbirds are still nesting at Bombay Hook, probably tending a second brood.Look up! A migrating Bobolink passes over the dike at Shearness Pool.Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.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.A Great Egret prowling Shearness Pool.A Snowy Egret in Bear Swamp Pool.Wood Ducks in Bear Swamp Pool.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.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.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 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.A male Atlantic Marsh Fiddler Crab peers from its den.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.A Green Heron seen just before descending into the cordgrass to find fiddler crabs for dinner.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 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 in the marshes opposite Shearness Pool.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 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 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.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.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.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.The White-tailed Deity is common along the road to Finis Pool.Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.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.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.
Here’s a look at some native plants you can grow in your garden to really help wildlife in late spring and early summer.
The showy bloom of a Larger Blue Flag (Iris versicolor) and the drooping inflorescence of Soft Rush (Juncus effusus). These plants favor moist soils in wetlands and damp meadows where they form essential cover and feeding areas for insects, amphibians, and marsh birds. Each is an excellent choice for helping to absorb nutrients in a rain garden or stream-side planting. They do well in wet soil or shallow water along the edges of garden ponds too.The fruits of Smooth Shadbush (Amelanchier laevis), also known as Allegheny Serviceberry, Smooth Serviceberry, or Smooth Juneberry, ripen in mid-June and are an irresistible treat for catbirds, robins, bluebirds, mockingbirds, and roving flocks of Cedar Waxwings.Also in mid-June, the fragrant blooms of Common Milkweed attract pollinators like Eastern Carpenter Bees,……Honey Bees,……and butterflies including the Banded Hairstreak (Satyrium calanus). In coming weeks, Monarch butterflies will find these Common Milkweed plants and begin laying their eggs on the leaves. You can lend them a hand by planting milkweed species (Asclepias) in your garden. Then watch the show as the eggs hatch and the caterpillars begin devouring the foliage. Soon, they’ll pupate and, if you’re lucky, you’ll be able to watch an adult Monarch emerge from a chrysalis!
Are you worried about your well running dry this summer? Are you wondering if your public water supply is going to implement use restrictions in coming months? If we do suddenly enter a wet spell again, are you concerned about losing valuable rainfall to flooding? A sensible person should be curious about these issues, but here in the Lower Susquehanna River Watershed, we tend to take for granted the water we use on a daily basis.
This Wednesday, June 7, you can learn more about the numerous measures we can take, both individually and as a community, to recharge our aquifers while at the same time improving water quality and wildlife habitat in and around our streams and rivers. From 5:30 to 8:00 P.M., the Chiques Creek Watershed Alliance will be hosting its annual Watershed Expo at the Manheim Farm Show grounds adjacent to the Manheim Central High School in Lancaster County. According to the organization’s web page, more than twenty organizations will be there with displays featuring conservation, aquatic wildlife, stream restoration, Honey Bees, and much more. There will be games and custom-made fish-print t-shirts for the youngsters, plus music to relax by for those a little older. Look for rain barrel painting and a rain barrel giveaway. And you’ll like this—admission and ice cream are free. Vendors including food trucks will be onsite preparing fare for sale.
And there’s much more.
To help recharge groundwater supplies, you can learn how to infiltrate stormwater from your downspouts, parking area, or driveway…
Does your local stream flood every time there’s a downpour, then sometimes dry up during the heat of summer? Has this problem gotten worse over the years? If so, you may be in big trouble during a drought. Loss of base flow in a stream or river is a sure sign of depleted groundwater levels in at least a portion of its drainage basin. Landowners, both public and private, in such a watershed need to start infiltrating stormwater into the ground instead of allowing it to become surface runoff.You can direct the stormwater from your downspout, parking area, or driveway into a rain garden to help recharge the aquifer that supplies your private or public well and nearby natural springs. Displays including this model provided by Rapho Township show you how.
…there will be a tour of a comprehensive stream and floodplain rehabilitation project in Manheim Memorial Park adjacent to the fair grounds…
Have you seen banks like these on your local stream? On waterways throughout the Lower Susquehanna River Watershed, mill dams have trapped accumulations of sediments that eroded from farm fields prior to the implementation of soil conservation practices. These legacy sediments channelize creeks and disconnect them from their now buried floodplains. During storms, water that would have been absorbed by the floodplain is now displaced into areas of higher ground not historically inundated by a similar event.Adjacent to the Manheim Farm Show grounds, the Chiques Creek Stream Restoration Project in Manheim Memorial Park has reconnected the waterway to its historic floodplain by removing a dam and the legacy sediments that accumulated behind it.Chiques Creek in Manheim following removal of hundreds of truck loads of legacy sediments. High water can again be absorbed by the wetlands and riparian forest of the floodplain surrounding this segment of stream. There are no incised banks creating an unnatural channel or crumbling away to pollute downstream waters with nutrients and sediment. Projects similar to this are critical to improving water quality in both the Susquehanna River and Chesapeake Bay. Closer to home, they can help municipalities meet their stormwater management (MS4) requirements.Mark Metzler of Rettew Associates guides a tour of the Chiques Creek rehabilitation. Here, cross vanes, stone structures that provide grade control along the stream’s course, were installed to gently steer the center of the channel away from existing structures. Cross vanes manipulate the velocity of the creek’s flow across its breadth to dissipate potentially erosive energy and more precisely direct the deposition of gravel and sediment.
…and a highlight of the evening will be using an electrofishing apparatus to collect a sample of the fish now populating the rehabilitated segment of stream…
Matt Kofroth, Lancaster County Conservation District Watershed Specialist, operates a backpack electrofishing apparatus while the netting crew prepares to capture the temporarily stunned specimens. The catch is then brought to shore for identification and counting.
…so don’t miss it. We can hardly wait to see you there!
With temperatures on the rise in this morning’s bright sunshine, a flight of Eastern Subterranean Termites (Reticulitermes flavipes) streamed from the shelter of this tree snag to ascend skyward in a spreading cloud of kings and queens looking to start new colonies of wood chompers.
A nuptial flight of Eastern Subterranean Termites taking to the wing after ascending a dead tree alongside a small pond.
As the swarm cleared the treetops, it immediately attracted the attention of some recently-arrived migratory birds…
Barn Swallows and Chimney Swifts seized the opportunity to devour an easy meal…hundreds of flying termites. Their timing was perfect. The first Barn swallows of the season arrived here just two days ago, the first appearance of the swifts was concurrent with this morning’s swarm.Our squadron of predators quickly devoured the airborne insects. The entire event was concluded in just five minutes.
Visible in the background of this image, an infestation of invasive Emerald Ash Borer larvae has killed the trees in a woodlot comprised exclusively of Green Ash. Left standing, the dead snags provide excellent habitat for a number of animal species including cavity-nesting birds like woodpeckers, known consumers of these destructive larvae. To reforest the mowed field in the foreground, a variety of native deciduous trees have been planted. In areas where a diversity of trees are not present to furnish a source of seeds for natural succession, manually planting an array of seedlings provides some insurance against the risk of allowing establishment of a single pioneer species such as the vulnerable Green Ash. The white plastic tubes on the young trees offer protection from the ever-browsing White-tailed Deity.
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.
We photographed these Blue-winged Teal and American Black Ducks as they were feeding in a meadow wetland…
..but upon closer inspection we located…
…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.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…
…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.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…
…a hen Ring-necked Pheasant on a nest.
THE BAD EGG
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…
…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.
Have you noticed a purple haze across the fields right now? If so, you may have wondered, “What kind of flowers are they?”
A purple haze of color stretches across fields not already green with cold-season crops like winter wheat.
Say hello to Purple Dead Nettle (Lamium purpureum), a non-native invasive species that has increased its prevalence in recent years by finding an improved niche in no-till cropland. Purple Dead Nettle, also known as Red Dead Nettle, is native to Asia and Europe. It has been a familiar early spring “weed” in gardens, along roadsides, and in other disturbed ground for decades.
Purple Dead Nettle owes its new-found success to the timing of its compressed growing season. Its tiny seeds germinate during the fall and winter, after crops have been harvested and herbicide application has ended for the season. The plants flower early in the spring and are thus particularly attractive to Honey Bees and other pollinators looking for a source of energy-rich nectar as they ramp up activity after winter lock down. In many cases, Purple Dead Nettle has already completed its flowering cycle and produced seeds before there is any activity in the field to prepare for planting the summer crop. The seeds spend the warmer months in dormancy, avoiding the hazards of modern cultivation that expel most other species of native and non-native plants from the agricultural landscape.
Flowering Purple Dead Nettle as a volunteer cover crop among last year’s corn stubble in a no-till field.Like the flowers of orchids, Purple Hedge Nettle blossoms are described as yoke shaped or bilateral (zygomorphic). Psychedelic experiences are produced only through observation, not by ingestion. A member of the mint family, its edible young leaves and tops have nutritional value, making a unique addition to salads and soups.We call them “weeds”, but what do we know? Purple Dead Nettle, Common Dandelion, and Shepherd’s Purse (Capsella bursa-pastoris), three edible non-native invasive species with similar life cycles seen here flowering along a rural road among fields where intensive farming is practiced. Shepard’s Purse, like many members of the mustard family, is already producing seeds at the bottom of the flower cluster by the time the uppermost buds open for business.In preparation for seeding of a warm-season crop, herbicide is applied on a no-till field to kill Shepherd’s Purse and other cool-season plants. To help prevent sediment and nutrient discharge from lands where high-intensity agriculture is practiced, no-till methods are used to reduce runoff from the areas of bare soil that would otherwise be created by traditional plowing.
While modern farming has eliminated a majority of native plant and animal species from agricultural lands of the lower Susquehanna valley, its crop management practices have simultaneously invited vigorous invasion by a select few non-native species. High-intensity farming devotes its acreage to providing food for a growing population of people—not to providing wildlife habitat. That’s why it’s so important to minimize our impact on non-farm lands throughout the remainder of the watershed. If we continue subdividing, paving, and mowing more and more space, we’ll eventually be living in a polluted semi-arid landscape populated by little else but non-native invasive plants and animals. We can certainly do better than that.
It’s so tiny, you can’t even feel it crawling on your skin. It’s the Deer Tick (Ixodes scapularis), also known as the Black-legged Tick, and it’s already looking for someone to latch on to. Don’t let it be you. After your foray outdoors, be certain to shower and conduct a full body search for these little hitchhikers. Then, remember to launder the clothing you were wearing. Deer Ticks in the Lower Susquehanna River Watershed frequently transmit Borrelia burgdorferi, the bacteria that causes Lyme disease, and can be vectors of other microbiological pathogens as well. The specimen in this photograph is an adult male. Adult females are similar, but the edge of the abdomen has a crescent-shaped reddish border. The nymphal stage tick, which is half the size of an adult, is even more likely to infect humans with the Lyme disease bacteria, so be extra vigilant.
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…
This linear grove of mature trees, many of them nearly one hundred years old, is a planting of native White Oaks (Quercus alba) and Swamp White Oaks (Quercus bicolor).
Imagine the benefit of trees like this along that section of stream you’re mowing or grazing right now. The Swamp White Oak in particular thrives in wet soils and is available now for just a couple of bucks per tree from several of the lower Susquehanna’s County Conservation District Tree Sales. These and other trees and shrubs planted along creeks and rivers to create a riparian buffer help reduce sediment and nutrient pollution. In addition, these vegetated borders protect against soil erosion, they provide shade to otherwise sun-scorched waters, and they provide essential wildlife habitat. What’s not to love?
Autumn leaf of a Swamp White Oak
The following native species make great companions for Swamp White Oaks in a lowland setting and are available at bargain prices from one or more of the County Conservation District Tree Sales now underway…
The Red Maple is an ideal tree for a stream buffer project. They do so well that you should limit them to 10% or less of the plants in your project so that they don’t overwhelm slower-growing species.The River Birch (Betula nigra) is a multi-trunked tree of lowlands. Large specimens with arching trunks help shade waterways and provide a source of falling insects for surface-feeding fish. Its peeling bark is a distinctive feature.The Common Winterberry with its showy red winter-time fruit is a slow-growing shrub of wet soils. Only female specimens of this deciduous holly produce berries, so you need to plant a bunch to make sure you have both genders for successful pollination.An American Robin feeding on Common Winterberry.Common Spicebush is a shrub of moist lowland soils. It is the host plant for the Spicebush Swallowtail butterfly and produces small red berries for birds and other wildlife. Plant it widely among taller trees to provide native vegetation in the understory of your forest.Common Spicebush foliage and berries in the shade beneath a canopy of tall trees.The Common Pawpaw a small shade-loving tree of the forest understory.Common Pawpaw is a colony-forming small tree which produces a fleshy fruit. It is the host plant for the caterpillars of the Zebra Swallowtail.The Buttonbush is a shrub of wet soils. It produces a round flower cluster, followed by this globular seed cluster.And don’t forget the Eastern Sycamore, the giant of the lowlands. At maturity, the white-and-tan-colored bark on massive specimens makes them a spectacular sight along stream courses and river shores. Birds ranging from owls, eagles, and herons to smaller species including the Yellow-throated Warbler rely upon them for nesting sites.Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore.
So don’t mow, do something positive and plant a buffer!
Act now to order your plants because deadlines are approaching fast. For links to the County Conservation District Tree Sales in the Lower Susquehanna River Watershed, see our February 18th post.
Flies? Cabbage White butterflies? Can it really be a late-February day? It certainly is. Here are a few more signs of an early spring.
Green Frogs were out and about on this balmy February day trying to latch on to one of those flying insects. Their long winter’s nap lasted just over six weeks.Approximately two hundred Common Grackles passed by susquehannawildlife.net headquarters today. This one stopped to have a look around before continuing its northbound expedition.Difficult to spot, hundreds of high-flying Canada Geese were seen in the hazy sky above the headquarters garden during the late morning. These migrants are working their way north from Chesapeake Bay and won’t be seen again in our region until fall.
County Conservation District Tree Sales are underway throughout the Lower Susquehanna River Watershed. Now is the time to order for pickup in April. The prices are a bargain and the selection is fabulous. For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue). And don’t forget to order bundles of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local birds. They’re only $12.00 for a bundle of 10—can’t beat that deal!
Pickup on: Thursday, April 20, 2023 or Friday, April 21, 2023
Don’t mow it. Plant a meadow or pollinator garden instead.Both Cumberland and Perry Counties are offering a native warm-season grass and wildflower seed mix for planting your own meadow or pollinator garden. Perry County is also taking orders for a seed mix specifically formulated to grow plants for attracting hummingbirds and butterflies.
Pickup on: Thursday, April 20, 2023 or Friday, April 21, 2023
The Eastern Hemlock, Pennsylvania’s official state tree, is an excellent choice for addition to your landscape or reforestation project. It tolerates rocky soils and its cones are an excellent source of food for birds ranging from chickadees to finches.
The handsome yet underused Northern Red Oak is a sturdy long-lived native tree that is ideal for street-side, lawn, and reforestation plantings. In spring, it can be a magnet for migrating Neotropical birds when its flowers attract a wide variety of tiny insects to its upper reaches. Unlike many other oaks, this species is a relatively fast grower.
In autumn, even after the bright red foliage is gone, the berries of mature Black Gum (Nyssa sylvatica) trees attract a wide variety of birds like this Pileated Woodpecker. The Lebanon County Conservation District is offering Black Gum, also known as Black Tupelo, during their 2023 tree sale. Why not order and plant a half dozen or more?
The Perry County Conservation District is not only offering plants during this year’s sale, you can also purchase bluebird nest boxes for just $12.00 each!For less than the cost of one year of mowing, this stream corridor in Conewago Township, Dauphin County was reforested by the owner with hundreds of native trees, the majority purchased through County Conservation District Tree Sale events spanning a period of several years. By replacing bare soil and mowed areas, the riparian buffer created by these plantings has significantly reduced the nutrient and sediment loads that were polluting the small stream therein known as Brill’s Run. With determination and not a lot of money, you can do it too.But don’t forget the Eastern White Pines!
The frosted wing edges let you know that this is the winter form of the Eastern Comma butterfly. Adult commas, also known as anglewings, will soon enter crevices in dead and living trees to begin hibernation. On some occasions, they’ll seek shelter from the cold among voids in man-made structures. Look for commas on mild winter days when they awaken to zip around sunny woodlands and gardens. You may even see these speedy little fliers pausing to feed on tree sap or carrion.
If you happen to see a large dark dragonfly cruising around on a sunny November afternoon, it’s a pretty safe bet that it’s a Shadow Darner. These hardy odonates often persist even after the flights of migratory species have ended for the year. Shadow Darners are particularly fond of patrolling the shady edges of woodlands where they snag insects and devour them in midair. Though they are most often found breeding in beaver ponds and other quiet waters, we’ve had them successfully reproduce in the fish-free frog and tadpole pond at susquehannawildlife.net headquarters.
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!
Q: What’s scariest thing about having Brown Marmorated Stink Bugs over for Halloween?A: They bring along their friends.
The harmless, herbivorous Northern Walkingstick (Diapheromera femorata), also known as the Common Walkingstick, is well camouflaged when among the twigs and stems of deciduous trees. As foliage drops in autumn, these wingless insects often descend to ground level and sometimes venture into view. This individual was found in the vicinity of ideal habitat: a portion of forest including Black Cherry and Black Oak (Quercus velutina) trees. Juvenile Northern Walkingsticks feed on the leaves of the former, adults on those of the latter.
