Beetles (Coleoptera) – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

August 3, 2026August 3, 2026

No, this is not an account chronicling a British invasion, especially during the month we celebrate the country’s 250th anniversary of its separation from commonwealth rule. This is instead a short introduction to some of the numerous regional insects of the order Coleoptera.

Globally, there are somewhere between 300,000 and 2 million or more species of beetles, depending on who’s doing the enumerating. A commonly settled upon number is 400,000, which makes beetles account for about 40% of the known insect species and 25% of the animals in the world. In the United States, there are almost 30,000 species.

Morphological variation among individuals in a population of beetles is easily observed. These differences often manifest into adaptations that provide a survival advantage and speciation. It therefore comes as no surprise that beetles were among the life forms studied by Charles Darwin as he pondered natural selection and preparation of The Origin of Species.

Beetle Display at North Museum — During the nineteenth century, Professor Samuel Stehman Haldeman and other members of the Linnaean Society of Lancaster City and County made sizeable collections of beetles. Haldeman mentored society treasurer Simon S. Rathvon’s interest in the insects and he in turn curated the 12,000 beetles in the society’s holdings. The beetle case seen in the photograph is on display at the North Museum on the campus of Franklin and Marshall College in Lancaster. Many of the Linnaean Society of Lancaster City and County’s specimens were moved from the custody of the college to the museum upon its opening in 1953. (For more on the Lancaster Linnaeans, see our post from February 25, 2018, titled “A Century of Extinction” or, better yet, visit the North Museum.)

If it’s organic, living or dead, a beetle has probably become specially adapted to fill the role of reducing it or consuming it. Beetles are indispensable members of the ecosystems they inhabit. Many function as scavengers, breaking down dead plants or animals into the basic nutrients that renew life. There are those that consume rotting wood, dung, and carrion. Sometimes they eat these things when people would rather they didn’t—such as moist wood that’s part of a house. Then there are species of beetles that are herbivores, consuming parts of the plants that get their energy directly from the sun. There are beetles that eat stems, roots, leaves, buds, flowers, nectar, sap, seeds, and fruit—many specializing in particular plant species or families. Some of these herbivorous primary consumers come to our attention because their populations explode in response to our creation of monocultures of their favored food, but many more act as pollinators for plants critical to human survival. Linnaean Society treasurer Rathvon made these herbivore-plant relationships the focus of many of his nineteenth-century writings, particularly as they affected agriculture. On the upper trophic levels, there are the predatory beetles that feed on herbivores or other carnivores. Many of these species have narrowed their choice of prey to one or fewer species. For example, there is a beetle that feeds only on the subterranean nymphs of cicadas.

Beetles and Trophic Levels — Beetles occupy numerous trophic levels within the food chain. Staghorn or stag beetle (Lucanidae) larvae are reducers that feed on rotting wood. Meanwhile the adults, which are sometimes attracted to man-made lights, consume sap. A herbivorous primary consumer, the Red Milkweed Beetle (Tetraopes tetrophthalmus), a member of the long-horned beetle family (Cerambycidae), feeds exclusively on Common Milkweed. Ladybird beetles (Coccinellidae), also known as ladybugs, are secondary consumers and favorites of gardeners due to their appetite for aphids throughout most of their lives. (Click the image for a larger version)

Ladies and gentlemen, the beetles…

The Dogbane Beetle (Chrysochus auratus) is one of the leaf beetles (Chrysomelidae), a family which includes numerous agricultural pests. However, as its name suggests, this beetle feeds on dogbane (Apocynum species), a milkweed-like plant of woodland edges and early successional habitats, so it poses no threat to crops or ornamentals.

May Beetles or Junebugs — The large family of scarab beetles (Scarabaeidae) includes dung beetles and other important detritus-feeding decomposers. The may beetles, also known as junebugs, seen here are probably of the genus Phyllophaga, but species-level identification typically requires lab examination.

May Beetle or Junebug — Adult may beetles feed on a variety of leaves throughout the night. The larvae consume the roots of grasses and other plants. Neither life stage does significant damage, but skunks have a passion for digging in lawns to find the larval grubs.

Big Brown Bats are the only commonly encountered flying mammal remaining in the lower Susquehanna valley. To provide the nutrition and energy they need to raise young and store up reserves for hibernation, Big Brown Bats consume large quantities of night-flying scarab beetles (including Phyllophaga species) throughout the summer and fall. In addition, their survival relies in large part upon the availability of adequate summertime birthing roosts in places like warm attics. Later in the year, their needs shift to wintering sites in caves, mines, and quiet old cellars where they don’t need to share space with colonies infected by the fungus Pseudogymnoascus destructans, the pathogen that causes White-nose Syndrome (WNS), a fatal disease that has wiped out 95% of the bats in some hibernacula. (United States Fish and Wildlife Service image by Pete Pattavina)

Adult Green June Beetles, also known as June Bugs, are often most evident in July. These diurnal herbivores normally consume fruit like this watermelon only after it begins rotting or has been damaged by some other animal. The larvae are mostly detrivores, specializing in consuming mold and humus, especially among the roots of plants that lie beneath layers of mulch or thatch. The grubs are preyed upon by skunks, birds, and moles.

Striped Skunk — Skunks digging among grasses are often harvesting the larvae of many different species of scarab beetles.

Eastern Bluebird Eating Mealworm — Mealworms are the commercially raised larvae of the Yellow Mealworm Beetle (Tenebrio molitor), a species of darkling beetle in the family Tenebrionidae. Perpetual pests in food storage, the grubs are now raised for research and as food for humans and insectivorous animals like this Eastern Bluebird supplementing its winter diet at our headquarters feeding station.

Click beetles (Elateridae) have an articulating prothorax that snaps and propels the insect into the air as a protrusion resembling a spine “clicks” into a furrow on its ventral surface. These sudden launches can help the click beetle escape a potential predator.

Like the previous individual, this click beetle was attracted to man-made light. The larvae consume small rootlets, seeds, and tubers in soil and among decaying organic matter.

Another member of the click beetle family, the Eyed Elator (Alaus oculatus) mimics the head of a snake or other predator to avoid assuming the role of victim. The larvae feed among the stumps and roots of dead and dying forest trees consuming the larvae of wood-boring insects.

The Six-spotted Tiger Beetle (Cicindela sexgutata) is a familiar sight on sun-dappled forest paths. It is a fast-running predator, consuming ants, spiders, and other small arthropods. The larvae ambush hunt from the entrance to their burrow, quickly snagging prey as it passes by.

The aquatic larvae of the Giant Water Scavenger Beetle (Hydrophilus triangularis) are voracious predators consuming snails, other invertebrates, tadpoles, and even small fish. In some waters, they may contribute to the control of mosquitos. The adults are herbivores and scavengers. Some, like this one, are attracted to lights at night.

Photinus Firefly — Fireflies, also known as lightning bugs, are renowned for their ability to produce a flash of light to attract a mate on a warm summer evening. Both sexes of fireflies in the genus Photinus (seen here) produce pulses of yellow light through the chemical reaction known as bioluminescence. Their larvae feed mostly on earthworms. The genus Photuris includes the Pennsylvania Firefly (Photuris pennsylvanica), the keystone state’s official insect, but a beetle that is not particularly plentiful in the commonwealth. Photuris flashes are greenish in color and begin a bit later, usually after dark. Their larvae are scavengers, consuming fallen insects and fruits. A third genus, Pyractomena, flashes amber light. Its larvae consume snails and can be seen ascending vegetation above damp soil along the shorelines of quiet segments of the lower Susquehanna River at nightfall.

Photinus pyralis, the Common Eastern Firefly, is the most widespread and numerous “lightning bug” in the Lower Susquehanna River Watershed. Want to see more fireflies around your place next summer? It’s easier then you might think. Just turn out the lights, skip the the lawn treatments, and let more space rewild to tall, mature grass and herbaceous growth, then watch the magic. The star-like twinkles of glowing beetles will be signaling, “I want to hold your hand,” throughout your private firefly refuge.

Male Common Eastern Firefly "Dipping" — Because the male Common Eastern Firefly dips downward then makes an upward swing while illuminating, the species is also known by the common name Big Dipper Firefly.

October 30, 2024October 31, 2024

A Towering American Elm

During the past week, Uncle Tyler Dyer has been out searching for autumn leaves to add to his collection. One of the species he had not encountered in previous outings was the American Elm (Ulmus americana), so he made a special trip to see a rare mammoth specimen in a small neighborhood park (Park Place) along Chestnut Street between 5th and Quince Streets in Lebanon, Pennsylvania.

American Elm at Park Place in Lebanon, Pennsylvania — Possibly the largest and oldest remaining American Elm in the lower Susquehanna watershed, the Park Place tree in Lebanon exceeds 60 feet in height and may be more than 300 years of age. In the nearly one hundred years since Dutch elm disease (DED) first began killing elms in eastern North America, this tree has been spared the fatal effects of the infection. DED is caused by several species of microfungi (Ophiostoma ulmi, O. himal-ulmi, and O. novo-ulmi) spread by numerous bark beetle (Curculionidae) species. As early as 1928, infected beetles arrived in the United States from the Netherlands among shipments of logs.

There’s still time to get out and see autumn foliage. With warmer weather upon us—at least temporarily—it’s a good time to go for a stroll. Who knows, you might find some spectacular leaves like these collected by Uncle Ty earlier this week. All were found adorning native plants!

Winged Sumac (Rhus copallina), a small native tree. In case you’re wondering, it’s not poisonous.

Black Chokeberry (Photinia melanocarpa), a native shrub also known as Aronia. It produces black-colored fruits in summer.

Red-osier Dogwood (Cornus sericea), a shrub that prefers wet or damp soils. It yields white fruits.

Maple-leafed Viburnum (Viburnum acerifolium), a native shrub of upland forest understories.

Highbush Blueberry (Vaccinium corymbosum), a native shrub and the source of many cultivated forms of the popular fruit.

To identify your finds, be certain to click the “Trees, Shrubs, and Woody Vines” tab at the top of this page to check out Uncle Ty’s extensive collection.

June 27, 2024

Photo of the Day

Clubbed Mydas Flies in Copula — **Love is in the Air-** The conspicuously large Clubbed Mydas Fly (Mydas clavatus) is a harmless mimic of the spider wasps (Pompilidae). They carry their masquerade to the extreme with bold behavior that includes pumping of their abdomen to simulate an ability to sting. Adults visit flowers to feed on pollen and nectar while the larvae are predatory, relying on a diet of scarab beetles (Scarabaeidae) which they find crawling within the dead and rotting wood where they reside. When mating, adults fly around in copula, reminding one of “love bugs” and other members of the fly family Bibionidae, the march flies. This mating pair was photographed along the Susquehanna at Conewago Falls.

June 5, 2024June 5, 2024

What’s in a Name?

March Fly, Bibio townesui — As the month of June gets underway, we spotted this male March Fly (Bibio species) visiting the susquehannawildlife.net headquarters garden.

And we found this Great Brown Drake (Hexagenia bilineata), a large species of burrowing mayfly, clinging to our building’s masonry wall after last night’s early June nuptial flight.

So when can we expect to see Green June Bugs (Cotinis nitida) devouring our discarded watermelon rinds? Probably not until July.

October 5, 2023March 30, 2024

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

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

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

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

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

SOLITARY WASPS

A Great Black Wasp on goldenrod (Solidago species). Like other solitary wasps, a female Great Black Wasp will sting and paralyze a host insect upon which she’ll deposit her eggs. After hatching, the larvae will begin consuming the host’s body as a source of protein. The parasitized insects are often katydids or grasshoppers.

A Great Black Wasp. — A Great Black Wasp feeding on nectar, a source of carbohydrates. Unlike social bees and wasps, solitary wasps are equipped with a stinger solely used for immobilizing prey, not defending a nest. They are therefore quite docile and pose little threat to humans.

A Great Black Wasp powdered with pollen. Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.

Thread-waisted Wasp — A female Thread-waisted wasp (Ammophilia species, probably A. nigricans) drags a paralyzed caterpillar to her excavated nest where she’ll deposit an egg on the body. After hatching, the larval wasp will feed on the disabled caterpillar. The protein will enable the larvae to grow, pupate, and later emerge as an adult wasp.

The female Eastern Cicada Killer (Sphecius speciosus) excavates an underground nest with branch tunnels connecting a dozen chambers or more. As the common name suggests, the female wasp paralyzes a cicada, then makes a strenuous effort to fly and drag it back to the nest for placement in a cell. Each male wasp egg is deposited upon just one immobilized cicada, but a female egg is provided with a cache of several cicadas to provide adequate protein for growth to a larger size. Nest cells are sealed with soil, then the larvae hatch in just a couple of days. Within about two weeks, they have consumed the cicada protein and are fully grown. Wrapped in a cocoon, they spend the winter in the nest, then pupate in the spring before emerging as a new generation of adults.

The Black-and-yellow Mud Dauber (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.

Pipe Organ Mud Dauber Nest — The Pipe Organ Mud Dauber builds this elaborate nest in which their eggs and paralyzed spiders are deposited in cells sealed with mud partitions. After consuming the spiders, the larvae pupate, overwinter, then emerge from their cells as adults during the following spring. To escape the protection of the nest, the new generation of adults bore through the mud walls. Adult Pipe Organ Mud Daubers resemble the Great Black Wasp, but have a white or yellow distal segment on their rear legs resembling a pair of light-colored socks.

Scavenger Flies in Pipe Organ Mud Dauber Nest — 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

SWEAT BEES

A Sweat Bee (Lasioglossum species). — A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).

An Augochlorine Green Sweat Bee (Augochlorini). — A female Augochlorine Green Sweat Bee (Augochlorini) collecting nectar on White Snakeroot. Notice the pollen “baskets” on the rear leg.

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). — 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 Mason Bee (Osmia species) emerging from a nest cell in spring. — A Mason Bee (Osmia species) emerging from a nest in spring. Mason Bees create nesting cells within preexisting cavities in wood, stone, and other other supporting structures. Within the nest cavity, each egg is deposited atop a cache of pollen and nectar, a pollen loaf, then enclosed behind a partition of mud. The female Mason Bee will usually repeat this process until an entire cavity is filled with cells. During the following spring, a new generation of adult Mason Bees digs its way through the cell walls to emerge and repeat the process. These bees readily use paper straws or holes drilled in blocks of wood for nesting.

A mason bee nest box with holes drilled into blocks of wood.

Parasitized Mason Bee Nest — Mason Bees seal each cell and the outer end of their nest cavity with mud. These outer nest cells can been parasitized by a variety of wasps. Here, the outer cell of a Mason Bee nest has been victimized by a tiny chalcid wasp (looks like another one to the lower left). Several species of female chalcid wasps (native Monodontomerus species or non-native Pteromalus venustus) enlarge weak points in the outer partition of a mason bee nest, then sting and paralyze the larval bee inside before depositing their eggs. Within the cell. the wasp larvae consume the larval Mason Bee and the “pollen loaf” provided for its growth. These same parasitic wasps prey upon Leafcutter Bees as well.

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

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.

A Common Eastern Bumble Bee pollinating a Great Rhododendron flower. — Flowering plants including the Great Rhododendron find success attracting pollinators to their reproductive blossoms by offering carbohydrate-rich nectar to insects like this Eastern Bumble Bee. The yellow spots on the flower’s upper petal help to guide visitors toward their sweet treat.

An Eastern Carpenter Bee feeding on goldenrod nectar. Compare the almost hairless abdomen to that of the bumble bees. Carpenter bees are semi-social insects. Females lay their eggs in cells within galleries bored into wood. These nests are completed with great precision, avoiding creation of any second entrance by mistakenly breaching the outer surface of the excavated wood. Each egg/larvae is provided with a supply of protein-rich pollen. Males often hover outside their mate’s nest to prevent competing males from entering the area.

A Honey Bee visiting goldenrod alongside Common Eastern Bumble Bees. — A worker Honey Bee, a female member of a sisterhood of foragers from a nearby hive, visits goldenrod alongside Common Eastern Bumble Bees. Honey Bees were brought to North America during the 1620s, the earliest years of the trans-Atlantic migration of European colonists, to pollinate cultivated plants and to provide a reliable source of honey and beeswax. Within the Honey Bee’s social structure, the queen of each hive lays the eggs to produce the female worker bees. Once each year, male drones are produced along with a new generation of queens.

Honey Bee Hive — In nature, Honey Bees build hives in tree cavities. Recently, this colony constructed a hive in a screech owl nest box at susquehannawildlife.net headquarters. To provide protein for the hatching larvae, worker bees collect pollen and deposit it within the hexagonal cells of the vertically aligned beeswax combs. After an egg is deposited upon the pollen cache, each cell is sealed with more beeswax. Young females tend these nest combs before maturing and becoming foraging worker bees.

Bee Hive Display — In apiculture, Honey Bees are raised in man-made hives. This Pennsylvania Association of Beekeepers display gives visitors to the Pennsylvania Farm Show in Harrisburg a look at the inner workings of a live bee hive. Nectar collected by worker bees is turned into honey to provide the supply of carbohydrates needed to fuel the colony through the winter. Note the honeycombs on the glass.

A possible Small Carpenter Bee Ceratina species). — A possible Small Carpenter Bee (Ceratina species) visiting White Snakeroot. Small Carpenter Bees nest inside hollow stems and twigs. Some species are eusocial, with a queen’s daughters and sisters sharing responsibility for finding food and rearing the young. Females overwinter inside a one of the excavated stems and begin a new nest there in the spring.

A Digger Bee (possibly Melissodes species). — A Digger Bee (possibly Melissodes species) with “pollen baskets” full of pollen collected from nearby flowers. Digger Bees in the genus Melissodes are often known as the Long-horned Bees. These social insects excavate underground nests and many species practice communal living.

SCOLIID WASPS

The Two-spotted Scoliid Wasp (Scolia dubia), also known as the Blue-winged Scoliid Wasp, is most frequently observed feeding on nectar. Scoliid wasps are solitary nesters, though they may assemble into groups while visiting flowers. They often ignore the presence of humans and are seldom disturbed by their presence. Females seek out the burrowing grubs of beetles including the Green June Bug (Cotinis nitida) and possibly the Japanese Beetle. After stinging a grub to paralyze it, the wasp will deposit her egg on its body, then bury it. Upon hatching, the larval wasp will feed on the grub for nourishment as it grows.

June Bugs eating watermelon. — Don’t like having your watermelon overrun by Green June Bugs while you’re eating? Then you ought to go out of your way to be nice to the Two-spotted Scoliid Wasp.

The Double-banded Scoliid (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.

The Northern Paper Wasp — 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.

Guinea Paper Wasps (Polistes exclamans) at their nest. — Common Paper Wasps (Polistes exclamans), also known as Guinea Paper Wasps, at their open-cell nest. This and the nests of most other paper wasps are suspended on a filament or a pedicle. Many paper wasps can excrete an ant repellent on this section of the nest in an effort to prevent invasion. Like many other social hymenopterans, a defending wasp can secrete a pheromone venom during the stinging process to warn the colony of danger at the nest. In winter, Common Paper Wasps seek shelter in stumps and other locations to hibernate.

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.

Robber Fly consuming an Eastern Yellowjacket — Yellowjackets may be moody and aggressive, but they do fall victim to a number of predators. A Robber Fly (Promachus species) has taken down and is devouring this Eastern Yellowjacket.

A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew deposits — A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew on a Tree-of-heaven (Ailanthus altissima). In the absence of nectar-producing flowers, many bees, yellowjackets, and hornets have turned to the invasive lanternfly and Ailanthus combo to turn the sun’s energy into the carbohydrates they need. For protein, they prey upon spiders, flies, caterpillars, and a variety of other insects.

A Bald-faced Hornet collecting wood pulp from the surface of a weathered picnic table. — To create paper for nest construction, this Bald-faced Hornet is collecting wood pulp from the surface of a weathered picnic table. Away from the nest, these hornets demonstrate a calm, carefree demeanor and can be closely observed.

Bald-faced Hornet Nest — A Bald-faced Hornet nest in a pine tree. These hives are strictly temporary. Within the nest, a generation of drones (males) and new queens are produced late each year. These wasps leave the colony to mate. With the arrival of freezing weather, all inhabitants within the nest, including the old queen, perish, as do the drones that departed to breed. Only the new queens survive winter hibernation to propagate the next generation of wasps, starting with the workers needed to construct a fresh nest and reestablish the colony.

Bald-faced Hornets Peering from Nest — Did you ever get the feeling you’re being watched? Don’t go messing around with Bald-faced Hornet nests. The occupants therein, like other social bees, wasps, and hornets, are equipped with stingers and venom for defending their colony. This is an adaptation that has developed over time to assure the survival of populations of these insects. Think about it this way, a solitary wasp that loses a nest loses only their individual brood of offspring. There is minimal impact on the wider local population of such insects. Conversely, a social wasp or hornet that loses a nest loses an entire colony, possibly negating the benefits of their cooperative behavior and threatening the survival of the species. Insects that cooperate to build societies for survival can be more vulnerable to the catastrophic impacts of certain circumstances like disease, weather, and invasion of their colonies. Therefore, natural selection has provided them with contingencies for these dangers, for example, the instinct to construct protective shelters and the adaptation of stingers and venom for defense against intruders and would-be predators. Oh, and by the way, the Bald-faced Hornet can spray venom, often aiming for the eyes, so keep your distance.

European Hornets (Vespa crabro), an introduced species, are predatory on a variety of flying insects for protein. For carbohydrates they are attracted to sweets like this lanternfly honeydew on Tree-of-heaven.

European Hornets constructing a nest in a tree cavity. — European Hornets constructing a paper nest in a tree cavity.

POTTER WASPS

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

ANTS

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

A farmland desert. — How can anyone be surprised by the absence of bees and other pollinators in farmland? Manicured and cultivated ground offers little in the way of year-round shelter and food sources for insects and other wildlife.

A savanna-like habitat. — This savanna-like habitat on a south-facing slope provides the abundance of nectar-producing, pollen-rich wildflowers needed to nourish a diverse population of insects including bees, wasps, hornets, and ants. Goldenrods, asters, and White Snakeroot are some of their late-season favorites.

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

SOURCES

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

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

September 8, 2023September 8, 2023

Photo of the Day

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.

April 12, 2023May 26, 2026

Photo of the Day

A Reforestation Project — Visible in the background of this image, an infestation of invasive Emerald Ash Borer larvae has killed the trees in a woodlot composed 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.

September 17, 2022

Photo of the Day

Purple Finch feeding on Green Ash seeds. — It seems a bit early, but Purple Finches are indeed beginning to transit the Lower Susquehanna River Watershed on their way south. This one is feeding on the abundance of seeds produced by a Green Ash that has, at least thus far, survived the Emerald Ash Borer invasion.

May 7, 2022May 13, 2022

Photo of the Day

Mollusks of the Lower Susquehanna River Watershed: Gray Garden Slug — The Gray Garden Slug (Deroceras reticulatum) is an invasive inhabitant of places subjected to human disturbance, especially cultivated farmland and, as the common name suggests, gardens. They are most active at night, hiding beneath plant litter, trash, and rocks during the daytime. This inch-long specimen was photographed while out and about on a recent dreary and damp afternoon. Natural enemies of terrestrial slugs include birds, toads, frogs, snakes, and some beetles in the family Caribidae. In the field and vegetable patch, keeping leaf litter and other debris away from the base of young plants can reduce damage caused by these hungry mollusks.

May 1, 2022September 15, 2022

Early May Migration

National Weather Service radar showed a sizeable nocturnal flight of migrating birds early this morning. Let’s go for a short stroll and see what’s around.

Radar returns from State College, Pennsylvania, display several bands of light rain and a massive flight of migrating birds. (NOAA/National Weather Service image)

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Gray Catbird — After coming in on an overnight flight, Gray Catbirds were numerous at dawn this morning.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Black-and-white Warbler — Masses of Neotropical migrants are just beginning to arrive. This Black-and-white Warbler was found feeding on insects in a Green Ash tree that, so far, has survived Emerald Ash Borer (Agrilus planipennis) infestation.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Veery — The Veery is a Neotropical thrush that nests in understory vegetation on forested slopes in the Lower Susquehanna River Watershed.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Orchard Oriole — Orchard Orioles are here.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Baltimore Oriole — And Baltimore Orioles are here too. Vibrant colors like these are what many observers find so wonderful about many of the Neotropical species.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Double-crested Cormorants — Not all migrants move at night. While you’re out and about, keep an eye on the sky for diurnal fliers like these migrating Double-crested Cormorants, seen this morning a full ten miles east of the river.

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Carolina Wren — While many birds are still working their way north to their breeding grounds, resident species like this Carolina Wren are already feeding young. This one has collected a spider for its nestlings.

December 21, 2019October 4, 2023

Some Autumn Insects

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

Bush Katydids (Scudderia species) are found in brushy habitats and along rural roadsides. Their green summer color fades to brown, maroon, and gold to match the autumn foliage where they hide. Bush katydids often remain active until a hard freeze finally does them in.

The Eastern Buck Moth (Hemileuca maia) is fuzzy, appearing to wear a warm coat for its autumn expeditions. Adults emerge in October and may fly as late as December. Females deposit their eggs on the twigs of Bear Oak (Quercus ilicifolia), Blackjack Oak (Q. marilandica), or Chestnut Oak (Q. montana), trees that, in our region, seem most favorable for the moth’s use when growing on burned barrens and mountain slopes. The spiny caterpillars are known to feed only on the foliage of these few trees. In the lower Susquehanna valley, the Eastern Buck Moth is rare because its specialized habitat is in short supply, and it’s all Smokey The Bear’s fault.

The Sachem (Atalopedes campestris) wanders north from the Atlantic Coastal Plain into the Susquehanna valley each summer. In some years they become the most numerous small orange butterfly of all, particularly around home gardens. The larvae will feed on Crabgrass (Digitaria species), but have not found success overwintering this far north. By November, adults begin to look pretty drab.

From 1978 through 1982, the Asian Multicolored Lady Beetle (Harmonia axyridis) was introduced into the eastern states by the United States Department of Agriculture. It has become a nuisance in many areas where it swarms, sometimes bites, and often overwinters in large smelly masses within homes and other warm buildings. As you may have guessed, it’s possibly displacing some of the less aggressive native lady beetle species.

On a chilly afternoon, a sun-warmed Bold Jumping Spider (Phidippus audax) pounced and dispatched this sluggish worker Honey Bee (Apis mellifera) that was trying to gather pollen from a late-season Purple Coneflower bloom. This spider is bold indeed.

Under bridges, inside bird nest boxes, and sometimes beneath porches, the female Pipe Organ Mud Dauber (Trypoxylon politum), a predatory wasp, builds these elaborate nests composed of long rows (pipes) of nursery cells. Into each cell one or more paralyzed spiders is deposited along with one of the female’s eggs. When hatched, each larva will feed upon the paralyzed spider(s) inside its cell, then pupate. The pupae overwinter, then emerge from their cells as adults during the following spring. In the autumn, males often stand guard at an entrance to the nest to prevent parasitic species, including some flies (look at the fifth pipe from the right), from laying eggs on the pupae. These wasps are not aggressive toward humans.

A Black-and-yellow Mud Dauber (Sceliphron caementarium) observes a neighboring nest of Common Paper Wasps (Polistes exclamans). The Common Paper Wasp, a species also known as the Guinea Paper Wasp, is a native of the southern United States. It is currently expanding its range into the lower Susquehanna valley from the Atlantic Coastal Plain. These two wasp species and the Pipe Organ Mud Dauber are known to regularly coexist. All three will take advantage of man-made structures for their nest sites. People using the picnic tables beneath this pavilion roof never noticed the hundreds of docile wasps above.

Those moody Eastern Yellowjackets (Vespula maculifrons) can get very temperamental during warm autumn days. These wasps may appear to have no enemies, but away from areas impacted by man’s everyday activities, they do. The Robber Fly (Promachus species) hunts like a flycatcher or other woodland bird, waiting on a perch along the forest’s edge for prey to pass by, then ambushing it, yellowjackets included.

The invasive Spotted Lanternfly, a native of eastern Asia, continues to spread destruction. It established itself throughout much of the east side of the lower Susquehanna River during the summer and fall of 2019. Their route of travel across the farmlands of the region intersects with plenty of vineyards to obliterate and few, if any, natural enemies. Expect them to begin colonizing the west shore en masse during 2020.

In 2020, plan to roll a few Spotted Lanternflies over, enjoy the view, and wait for the crimson tide to pass. With any luck, they’ll peak in a year or two.

SOURCES

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

August 31, 2018March 30, 2024

Noxious Benefactor

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

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

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

The flowers of the Common Milkweed were exceptionally fragrant this year. At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into our building and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from our walls (100 feet from his).

Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species). The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases. Are you following this? Remember as we proceed, milkweed is “noxious”.

Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.

A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.

Following the pollination of the flowers, seed pods will begin to grow. We trim these off the plants. The removal of the extra weight allows most of the stems to remain erect through stormy weather. You’ll still get new plants from underground runners. As you may have guessed, we’re trying to keep these plants upright and strong to host Monarch butterfly larvae.

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

Big Bluestem, a native warm-season grass in flower.

Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower. This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the herd animals and fires of the prairie to prevent succession and allow it to thrive.

Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.

Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.

Indiangrass (Sorghastrum nutans) in flower. This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA). They have an unbelievably large selection of indigenous species. You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.

A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea). Yes, it is that Echinacea, the same one used as a supplement and home remedy.

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

A female Monarch laying eggs on a Common Milkweed leaf.

A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf. Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.

Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf. There were over thirty of these caterpillars in just a ten by ten feet area this morning. We hope that if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!

A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.

Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant. Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle. Need more milkweed!

After benefiting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.

Two hours later, the chrysalis is complete.

Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one. An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.

There it is, soon ready to fly away. And all courtesy of the noxious milkweed.

A chrysalis can often be found on man-made objects too. This one is on the rim of a flower pot.

Ornamental flowers can attract adult Monarch butterflies seeking nectar. We’re now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides. There’s growing concern over the impact these compounds may be having on pollinating species of animals. Oh…and we don’t mow, whack, cut, mutilate, or spray herbicides on our milkweed, but you probably figured that out already.

SOURCES

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

August 20, 2017June 3, 2025

The Dungeon

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

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

Japanese Beetles (Popillia japonica) seen here on Halberd-leaved Rose Mallow. Without predation, exploding numbers of this invasive non-indigenous insect can defoliate and kill numerous species of plants in a given area.

The Song Sparrow (Melospiza melodia) is a generalist feeder, eating seeds and invertebrates including Japanese Beetles. This species is the omnipresent year-round occupant of shoreline vegetation along the lower Susquehanna River.

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

An “annual cicada” also known as a “dog-day cicada”, clings to the stem of a Halberd-leaved Rose Mallow at Conewago Falls.

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

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

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

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

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

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

SOURCES

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

Category: Beetles (Coleoptera)

Photo of the Day

Meet the Beetles

A Towering American Elm

Photo of the Day

What’s in a Name?

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

Photo of the Day

Photo of the Day

Photo of the Day

Photo of the Day

Early May Migration

Some Autumn Insects

Noxious Benefactor

The Dungeon