Month: July 2025

In previous episodes we visited sensational Asian giant hornets, a.k.a. murder hornets, and some of their look-alikes including European hornets and cicada killer wasps. Last week I received an inquiry about male cicada killers. A curious homeowner wondered if they were harmful to humans. This week we revisit an episode from a few years ago to learn about these amazing aerial acrobats. Sit back and relax, male cicada killers are harmless to humans but female cicada killers are lethal to annual cicadas. Female cicada killers kill cicadas as a food source for their young. During the daytime, female cicada killers hunt prey in the treetops where annual cicadas are found. Once captured and paralyzed, cicadas are interred in subterranean crypts. To see how female cicada killers roll, please check out this episode of Bug of the Week, “Cicadas beware, the ladies are in town: Female cicada killer, Sphecius speciosus”.

Although they appear fierce and perhaps even dangerous, male cicada killers pose no threat to humans or pets. Only females have a stinger, and try as he might, the male’s jaws and genitalia failed to puncture my skin. However, I have heard tales of females delivering a memorable defensive sting when inadvertently stepped on or trapped under knee or hand. Video credit: Paula Shrewsbury, UMD

But in advance of the appearance of the ladies, two male cicada killers established territories about twenty feet apart in my flower bed. So began a fierce competition for dominance of space and, I suppose, eventual access to the babes soon to emerge from the earth. Each morning shortly after sunrise as the morning sun warms the land, two feisty males arrive at their respective perches, one on a short yew bush and the other on the nozzle of my garden hose. As you will see in the video, they are on high alert, frequently leaving their perch for a short flight. Not quite understanding the thinking of the wasp mind, I imagine these forays are designed to provoke a battle with the other hopeful suitor. Occasionally, these sorties extend far enough from the perch that one male will enter the territory of the other. This results in a remarkable battle complete with frenetic buzzing and males interlocked in flight. It appears much biting and kicking goes on as evidenced by the response of a cicada killer when I captured one and held it. Eventually one breaks away and skedaddles toward my neighbor’s lawn with the victor in hot pursuit. But the victory seems fleeting. Male cicada killers either have remarkably short memories or indefatigable egos as the aftermath of these vicious mêlées soon results in both males returning to their perches only to repeat the battle a short time later.

One perched on a shrub, the other perched on my garden hose. These two fellows are pumped and looking for a tussle.  Short forays from the perch sometimes result in spectacular aerial battles as each tries to lay claim to the territory where females will soon appear.  Video credit: M. J. Raupp

Perhaps one sunny morning only one of these fierce flyers will remain and the vanquished will have departed for less ardently defended turf in search of his own mate.  But for now, with coffee in hand, this is the best early morning bug show in my garden.     

Acknowledgements

For more information about cicada killers including videos of them in action, please visit Chuck Holliday’s magnificent cicada killer website, BIOLOGY OF CICADA KILLER WASPS.

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For the better part of the last moth inquiries about spotted lanternflies have poured into my mailbox. One of the most interesting dealt with the appearance of a remarkable “albino” lanternfly spotted by an inquisitive citizen. Albinism in humans and other animals results when cells responsible for producing melanin, a pigment responsible for color of skin, hair, and eyes, fail to produce enough melanin.  While relatively common in humans and other vertebrates, albinism is rare in insects. The pale orange spotted lanternfly that inspired this story is likely a recently molted fourth instar lanternfly nymph.  Time out, what the heck does that mean? Lanternflies belong to a clan of insects called the Hemiptera. These insects have sucking mouthparts to sip plant fluids.  Their development includes three life stages, eggs, nymphs, and adults. From spotted lanternfly eggs hatch polka-dotted black and white juveniles called first instar nymphs. As they grow from one stage to the next, they shed their exoskeleton just like our more familiar blue crab. Once they shed their old skin, they are almost pure white for a while as their new skin hardens and begins to develop color. The second and third instar nymphs are also black with white spots. However, the last nymphal stage, the fourth instar nymph, is bright red with black patches and white spots when its pigmentation is complete. The picture that inspired this episode is a newly molted fourth instar nymph in the process of turning from pale orange to brilliant red.

Last May in the DMV spotted lanternfly nymphs hatched from eggs. Newly hatched lanternflies are pure white and appear to be albino, but soon they turn jet black and are speckled with white polka dots. For months they have been feeding on leaves and stems of plants in landscapes and gardens. But a few weeks ago, we began to see the beautiful fourth instar nymphs, their scarlet bodies covered with black patches and white spots. Last week reports of adult lanternflies streamed in as lanternflies landed on people and walked across windshields of cars. It won’t be long before hordes of lanternflies gather on trees, shrubs, and vines to feed.   So, get ready DMV, here come the lanternflies.   

The most frequently asked question in the Bug of the Week mailbag over the past two weeks is why are we seeing so many spotted lanternflies? At least three reasons help us understand why this is the case. First, let’s go back a decade or so to spotted lanternflies’ original detection in Berks County, PA.  In the intervening decade, spotted lanternflies have established and are reproducing in more than fifteen states. They have spread more than 600 miles away from ground zero in Berks County. More people are encountering lanternflies simply because they now occupy a much larger geographic area in the US. Here in the DMV we have gone from a few infested counties in Maryland and Virginia in 2018, to more than 60 infested counties. Yes, folks lanternflies are also in the District of Columbia.

Second, as lanternflies spread either by natural means or with assistance from humans, new colonies are established. These new infestations often are founded by an egg mass or two, each with 30 to 60 eggs, that hitched a ride on lawn furniture, a camper, or maybe a metal sculpture. For several years these pioneers might be off the radar, undetected, as was the case with the initial introduction of spotted lanternflies in Pennsylvania. With abundant food sources like the invasive tree of heaven and other delectable plants and low levels of predators, parasites, and pathogens tracking their burgeoning populations, lanternflies can enjoy a period of exponential growth. As satellite colonies merge along the ever-expanding lanternfly front and as populations expand in the generally infested area, more people encounter spotted lanternflies.  

Third, size matters. Bigger insects are more commonly noticed than smaller ones. Tiny lanternfly nymphs hatching from an egg are but a few millimeters long. They scuttle about vegetation on the forest floor and low-lying shrubs feeding on more than 100 plant species. However, by July, brilliant red nymphs have molted into tawny coated adults an inch or more in length. Being more than 20 times larger than their youngsters, adults are more readily noticed as they cluster on the trunks of trees or take flight and move about the landscape in search of food, mates, and places to deposit eggs. In reality, due to the high mortality of juveniles which is the hallmark of most insect species, there are far fewer lanternflies now than there were back in May when eggs first hatched. I’ll bet you are finding little or no solace in this.

You think Superman is faster than a speeding bullet? Just watch this lanternfly nymph jet away from the nosy camera. Watch again at one twentieth of normal speed. That’s one speedy bug.  

What’s next for spotted lanternfly here in the DMV? Hordes of adult lanternflies and their attendant deluge of honeydew soon will coat vegetation underlying lanternfly infested trees. Honeydew is a substrate for the growth of sooty mold, a non-pathogenic mold that cloaks leaves and stems of plants, reducing the ability of plants to capture the energy of sunlight and conduct photosynthesis. More disturbing will be the arrival of sugar junkies, hordes of wasps and bees intent on enjoying the carbohydrate bounty.   

Is there any good news here? As we learned last autumn, scientists at Penn State documented more than 1000 attacks by spiders, mantises, birds, and other predators of spotted lanternflies. Also getting in on the act are naturally occurring soil fungi that have caused at least one lanternfly population to collapse in Pennsylvania. In addition, spotted lanternflies are reported to kill one of their favorite sources of food, invasive tree of heaven. Here’s hoping Mother Nature continues to send help in mitigating the invasion of spotted lanternflies.          

For more information on the biology and management of spotted lanternfly click here.

Acknowledgements

Thanks to James Murdock for providing inspiration for this episode. Thanks also to Eloise and Abby Kollins and Paula Shrewsbury for wrangling and spotting spotted lanternflies. Wonderful resources provided by scientists at Penn State University and Cornell University were consulted to prepare this episode. The fascinating article “A pair of native fungal pathogens drives decline of a new invasive herbivore” by Eric H. Clifton, Louela A. Castrillo, Andrii Gryganskyi, and Ann E. Hajek was used as a reference for this episode.

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From the Bug of the Week mailbag: What happens when a wheel bug goes for a spin? Wheel bug, Arilus cristatus

In previous episodes we met one of the toughest customers in Mother Nature’s gang of beneficial insects, the wheel bug. Wheel bugs play an important role reducing populations of noxious invasive pests like brown marmorated stink bugs and they also dine on important forest pests including fall webworms and other native caterpillars. This week we received the following message about a wheel bug that thought it might be fun to take a spin in a rotating core in a paper mill. Here’s the message. “I just thought you would be interested to know that this bug crawled inside of a core with a diameter of 4.41inches and this core went in our winder. He was rotated at 8000fpm for about 150 seconds start to finish and survived. Looks like he was a little dizzy but he ended up crawling out and then flying towards our control panel. So we determined he deserved to live so we caught him in a bag and took him outside. Crazy the endurance and survivability on this thing!!!” 

I am not exactly sure how far this predator spun around, but at 8000 feet per minute for 2.5 minutes seem like it might have traveled some 20,000 feet in circles. I don’t know about you, but I’d be dizzy, if I survived.

Wheel bugs are fierce generalist predators. Watch as this female stalks a dagger moth caterpillar. She slowly circles to the head of the caterpillar to deliver a lethal jab with her strong beak. After sizing up the prey with her left foreleg and extending her beak, she makes a lightning-fast strike to capture her prey. Forest pests like fall webworm caterpillars are also on the menu. This female snares a webworm while on a romantic interlude with her mate. Wheel bugs regularly dine on other pests including brown marmorated stink bugs. With other members of Mother Nature’s hit squad, they contribute to the decline of stink bugs in many parts of the country.  

To round out this episode, here is a little more about wheel bugs and how they roll when not in a paper mill. The wheel bug is a species of assassin bug and, as the name implies, it kills other insects. The common name, wheel bug, stems from the fact that this terror has a structure on its back that looks like a spoke-bearing medieval torture device. The function of this wheel is known only to Mother Nature and the bug, but not to me. The business end of the wheel bug is the powerful beak or proboscis stored between the beast’s front legs when it is not in use. Upon spying a tasty morsel, the wheel bug cautiously approaches, embraces the mark with long front legs, and impales the victim with the powerful beak. The wheel bug pumps strong digestive enzymes through the beak into the prey. These enzymes liquefy the body tissues of the hapless victim. A muscular pump in the head of the bug slurps the liquefied meal up through the beak. Young wheel bugs use protein from their prey for growth and development and adult females convert prey into eggs. In autumn, the well-fed female wheel bug lays barrel-shaped eggs in clusters of several to more than one hundred usually on the bark of a tree. Eggs hatch the following spring in May and June.  Small wheel bugs, called nymphs, are magnificent creatures with bright red abdomens and orange antennae. They dine on a wide variety of insects including caterpillars, sawfly larvae, beetles, and other bugs. In most years, I feel lucky if I witness a half dozen of these monsters at work in the wild. With plant nurseries and landscapes laden with invasive pests like stink bugs and spotted lanternflies, it is not unusual to see scores of wheel bugs stealthily stalking and assassinating their stinky marmorated cousins and other invaders. How much benefit results from greater numbers of these assassins remains to be seen, but we hope that these bugs and other naturally occurring predators and parasites will help stem the onslaught of brown marmorated stink bugs, spotted lanternflies, and other invasive species. If you encounter wheel bugs, please heed this caution. While holding and admiring a wheel bug, I learned firsthand, so to speak, that the wheel bug could deliver a memorable, painful poke with its beak. If you keep wheel bugs as pets beware, try not to handle them directly or you too may become an unwitting victim of this clever assassin.

Acknowledgement

We thank Joshua Colgin for providing images and the fascinating story that inspired this episode.

This post appeared first on Bug of the Week

From the Bug of the Week mailbag: What happens when a wheel bug goes for a spin? Wheel bug, Arilus cristatus

In previous episodes we met one of the toughest customers in Mother Nature’s gang of beneficial insects, the wheel bug. Wheel bugs play an important role reducing populations of noxious invasive pests like brown marmorated stink bugs and they also dine on important forest pests including fall webworms and other native caterpillars. This week we received the following message about a wheel bug that thought it might be fun to take a spin in a rotating core in a paper mill. Here’s the message. “I just thought you would be interested to know that this bug crawled inside of a core with a diameter of 4.41inches and this core went in our winder. He was rotated at 8000fpm for about 150 seconds start to finish and survived. Looks like he was a little dizzy but he ended up crawling out and then flying towards our control panel. So we determined he deserved to live so we caught him in a bag and took him outside. Crazy the endurance and survivability on this thing!!!” 

I am not exactly sure how far this predator spun around, but at 8000 feet per minute for 2.5 minutes seem like it might have traveled some 20,000 feet in circles. I don’t know about you, but I’d be dizzy, if I survived.

Wheel bugs are fierce generalist predators. Watch as this female stalks a dagger moth caterpillar. She slowly circles to the head of the caterpillar to deliver a lethal jab with her strong beak. After sizing up the prey with her left foreleg and extending her beak, she makes a lightning-fast strike to capture her prey. Forest pests like fall webworm caterpillars are also on the menu. This female snares a webworm while on a romantic interlude with her mate. Wheel bugs regularly dine on other pests including brown marmorated stink bugs. With other members of Mother Nature’s hit squad, they contribute to the decline of stink bugs in many parts of the country.  

To round out this episode, here is a little more about wheel bugs and how they roll when not in a paper mill. The wheel bug is a species of assassin bug and, as the name implies, it kills other insects. The common name, wheel bug, stems from the fact that this terror has a structure on its back that looks like a spoke-bearing medieval torture device. The function of this wheel is known only to Mother Nature and the bug, but not to me. The business end of the wheel bug is the powerful beak or proboscis stored between the beast’s front legs when it is not in use. Upon spying a tasty morsel, the wheel bug cautiously approaches, embraces the mark with long front legs, and impales the victim with the powerful beak. The wheel bug pumps strong digestive enzymes through the beak into the prey. These enzymes liquefy the body tissues of the hapless victim. A muscular pump in the head of the bug slurps the liquefied meal up through the beak. Young wheel bugs use protein from their prey for growth and development and adult females convert prey into eggs. In autumn, the well-fed female wheel bug lays barrel-shaped eggs in clusters of several to more than one hundred usually on the bark of a tree. Eggs hatch the following spring in May and June.  Small wheel bugs, called nymphs, are magnificent creatures with bright red abdomens and orange antennae. They dine on a wide variety of insects including caterpillars, sawfly larvae, beetles, and other bugs. In most years, I feel lucky if I witness a half dozen of these monsters at work in the wild. With plant nurseries and landscapes laden with invasive pests like stink bugs and spotted lanternflies, it is not unusual to see scores of wheel bugs stealthily stalking and assassinating their stinky marmorated cousins and other invaders. How much benefit results from greater numbers of these assassins remains to be seen, but we hope that these bugs and other naturally occurring predators and parasites will help stem the onslaught of brown marmorated stink bugs, spotted lanternflies, and other invasive species. If you encounter wheel bugs, please heed this caution. While holding and admiring a wheel bug, I learned firsthand, so to speak, that the wheel bug could deliver a memorable, painful poke with its beak. If you keep wheel bugs as pets beware, try not to handle them directly or you too may become an unwitting victim of this clever assassin.

Acknowledgement

We thank Joshua Colgin for providing images and the fascinating story that inspired this episode.

This post appeared first on Bug of the Week

In previous episodes we visited delightful mason bees as they made an early debut and foraged for nectar and pollen to provision their nests inside cardboard tubes and galleried firewood in a mason bee colony. Tiny bee larvae will spend the next several months completing development before pupating in their chambers come fall, but right now all is not well in the realm of mason bees. Enemies are afoot. For the past several weeks, gangs of noisy yellow and black insects, leucospid wasps, have been carefully inspecting the modular condominiums of my mason bee colony. Leucospids are generally considered rare insects, but each year the tubular homes and woody tunnels housing mason bees attract scads of these parasites.

My mason bee condominium of cardboard tubes and galleries in wood provides homes for hundreds of mason bees to raise their young. But as spring turns to summer, danger arrives. Bee babies are hunted by clever leucospid wasps. With antennae tapping, a female leucospid wasp searches a mason bee log for clues to locate potential victims within. Once the bee larvae are located, she unsheathes the ovipositor and drills into the log to lay her eggs. In slow motion, watch as she unfolds her ovipositor and pirouettes on tip toes to drill into the wood. After depositing her eggs in the brood chamber, she pulls her ovipositor out and prepares to locate the next victim.  

Leucospids are rather unique in the wasp world. Unlike most of their kin with rear-facing or under-slung egg-laying tubes called ovipositors, leucospids carry their ovipositor arched up and over their back. The small yellow and black wasps move back and forth across the surface of the mason bee’s tubes and wooden lodgings tapping gently with their antennae and drumming with their abdomen. This behavior has been noted in other species of leucospids and is likely how the female wasp evaluates where the bee larvae reside and, perhaps, the suitability of the mason bees as a meal for her young. If the female leucospid likes what she finds, she uses her remarkable ovipositor to penetrate the cardboard tubes or my tough oak logs. She deposits eggs inside the cells of the developing mason bees. It is fascinating to watch the female wasps insert her ovipositor into mason bee galleries in search of bee larvae to serve as food for her young. After a few days, the wasp’s eggs hatch into voracious larvae that feed as ectoparasites attached to the outside of the bee larvae. Larvae of the parasitic wasps complete development and emerge as adults to find a mate and search for more victims.

I pondered the peril of my mason bee colony and soon realized that many of my hard-working bees would be spared from the treacherous leucospid wasp. When it comes to attacking bee larvae hidden in tubes, size does matter. The ovipositor of the leucospid wasp is only long enough to penetrate the outermost tubes of my modular mason bee condominium. Likewise, holes drilled in the center of my mason bee logs will remain unscathed. The vast majority of mason bees sheltered therein are well beyond the reach of leucospid’s dangerous egg-laying appendage. While some mason bee aficionados might cover their bee condominiums with netting to prevent parasitism, I let nature take its course. Rare leucospids are magnificent in their own way and part of the circle of life in the realm of insects.  

References

Two interesting articles, “Parasitic Behavior of Leucospis cayennensis Westwood (Hymenoptera: Leucospidae) and Rates of Parasitism in Populations of Centris (Heterocentris) analis (Fabricius) (Hymenoptera: Apidae: Centridini)” by Ana Lúcia Gazola and Carlos Alberto Garófalo, and “Osmia ribifloris, a Native Bee Species Developed as a Commercially Managed Pollinator of Highbush Blueberry (Hymenoptera:Megachilidae)” by P. F. Torchio, were used as references for this episode.

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