That Viral Video of the Giant Moth

There is currently a video of a giant moth that has gone viral, with a complement of completely incorrect identifications. This blog post will help sort fact from fiction and address the problems that stem from "oversharing" of such posts.

Here is the video, which elicits the full spectrum of human reactions from horror to beauty to fascination.

Giant moth

A truly horrible – and GIANT – moth.

Posted by The Daily Star on Tuesday, September 15, 2015

At first glance, the creature strongly resembles a sphinx moth. Indeed, given the location of Australia, many have identified it as the Privet Hawk Moth, Psilogramma menephron. The moth in the video is even larger, though, and the head and legs look a bit different.

It took a little bit of "Googling" myself to find the real answer. Turns out this is a "Giant Wood Moth," Endoxyla cinereus. Most people are not familiar with the carpenter moths of the family Cossidae, to which this herculean lepidopteran belongs, so it is no surprise that the moth in the video has been repeatedly misidentified.

This moth was formerly known as Xyleutes cinereus, which might add to the confusion. The caterpillars are grubs that bore in solid wood of eucalyptus trees. The adult female moth can have a wingspan of up to 23 centimeters; and it is the world's heaviest moth, weighing in at up to 30 grams.

Videos tend to command our attention, and we often forget to read the introductory material to learn where the subject was recorded, and other relevant information. Sometimes, the person posting the video fails to include those important details, too. Consequently, viewers may post comments that are not applicable. Before you know it, not only is the video going viral, but so is all the misinformation.

The speed with which erroneous "facts" are broadcast, often unwittingly, is at an all-time high thanks to the internet, so it is up to us as scientists and journalists to do the best we can to correct them, as quickly as we can. I urge you to use your own blogs, Facebook posts, Twitter, and other social media to do just that.

Pigeon Horntail Wasp Ovipositing

I first wrote about the Pigeon Tremex horntail wasp, Tremex columba, back in September, 2012. At that time I had not seen a female of that species here in Colorado. That all changed on the afternoon of August 22 when I witnessed two females of this species laying eggs (ovipositing) in an elm tree at my workplace, a plant nursery here in Colorado Springs.

Horntail wasps belong to the family Siricidae. They are mostly large, cylindrical wasps, the females of which have intimidating spear-like organs protruding from the end of the abdomen. They use this "ovipositor" and its associated appendages to bore into trees and lay their eggs. The larvae that hatch tunnel through the wood, aided by a wood-softening fungus that is deposited by their mother at the time she lays her eggs.

Close-up of ovipositor apparatus

Horntails get their name not from the ovipositor, but from a knob or spur at the tip of the abdomen above the ovipositor in females, but present in both genders. This “cornus” is a feature of the larva, too, aiding the grub in locomotion. The function of the cornus in adult wasps is apparently unknown.

The video below shows the female wasp already engaged in oviposition. Her ovipositor is the black rod perpendicular to her body under her hind leg. The rhythmic movements of her abdomen probably help drive the organ deeper into the wood. The pair of pale appendages extending from the tip of her abdomen function as a sheath that protects the ovipositor when it is not in use.

One reason the mother horntail attempts to lay her eggs deep inside the tree is to keep her offspring out of reach of giant ichneumon wasps and ibaliid wasps that lay their eggs on horntail grubs.

Female giant ichneumon wasp, Megarhyssa sp., from Colorado

Most horntail species are not considered pests because they will lay their eggs in dead, dying, or weakened trees. A handful of species have made their way to the United States from Asia and elsewhere, and those are invasive species that have no known natural enemies here in North America.

The favorite hosts for the Pigeon Tremex are maple and beech, but obviously elm is also acceptable, along with apple, poplar, oak, and other hardwoods. It takes one to two years for a horntail wasp to complete metamorphosis from egg to adult.

Sometimes, the female wasp dies in the act of ovipositing, or is consumed by a predator during this lengthy period of vulnerability. Indeed, on September 4 I found a deceased wasp still embedded in the tree where she was ovipositing; and nearby were the remains of another, just the needle-like ovipositor protruding from the tree trunk.

Deceased female horntail stuck in tree

This is the time of year to be watching for the Pigeon Tremex in your neck of the woods. Watch for their giant ichneumon parasites, too. You might have to spend a lot of time looking up and down dead trees, though.

Source: Eaton, Eric R. 2014. "The Wasp and the Fungus," Northern Woodlands Educators.

How to (Almost) Catch a Leaf-tier Caterpillar (Video)

Last week I wrote about a mason wasp that successfully captured a leaf-rolling caterpillar. Amazingly, the day after I made that observation, I saw another species of mason wasp hunting a slightly different kind of caterpillar. This time it was a female Ancistrocerus campestris attempting of fish out a leaf-tier caterpillar (genus Psilocorsis, family Amphisbatidae) from its shelter between two lashed-together oak leaves.

The drama unfolded at Tully Lake, between Athol and Royalston in north-central Massachusetts, by the boat launch. I happened to notice the same schizophrenic behavior in this wasp that I had observed in the female Ancistrocerus unifasciatus female the previous day. I turned on the video feature of my camera a number of times, for long durations, but this wasp's attempts were ultimately unsuccessful.

Leaf-tiers, in contrast to leaf rollers, can involve more than one leaf, creating a "sandwich" like the one the wasp is exploring in the images and video here. I concluded, given the host plant (oak), that this was likely the work of a caterpillar in the genus Psilocorsis in the family Amphisbatidae. That information also helped me in my assessment of the wasp's identity.

Ancistrocerus campestris is of average size for a mason wasp. The forewing length of females ranges from 9-11 millimeters, and 6.5-9 mm for males. The color pattern on the abdomen is fairly consistent, the hind margins of the first three abdominal segments colored in yellow. The genus Ancistrocerus can be identified by a transverse ridge along the front surface of the first abdominal segment, creating an abrupt angle and "face" that faces the rear of the thorax. In other genera the abdomen slopes more gently toward the thorax.

This time, the wasp did try to tear into the leaf shelter, evidenced by the holes she chewed in the surface of the top leaf. The brown patch is likely the result of the caterpillar feeding on the bottom surface of that top leaf. The wasp also ran around the entire edge of the shelter, trying to wiggle inside and grab the occupant.

Had she succeeded, she would have flown her prize to her nest, inside a pre-existing beetle boring in wood, a hollowed-out sumac twig, or an abandoned mud dauber nest. She divides such tunnels into cells, after completing a single cell by laying an egg and then caching several paralyzed caterpillars. She uses mud to make partitions between cells, and for the plug that closes a finished nest. A nest may contain anywhere between two and eleven individual cells. This wasp has, on one occasion, been seen taking over active nests of the keyhole wasp Trypoxylon clarkei, kicking out the rightful owner.

Besides caterpillars in the family Amphisbatidae, this mason wasp uses caterpillars from the family Gelechiidae ("twirler moths").

Nests can be invaded by parasites including the bee fly Toxophora amphitea, and the tiny eulophid wasp Melittobia chalybii. Grubs of the wedge-shaped beetle Macrosiagon cruentum may prey on the wasp larvae.

Ancistrocerus campestris can be found from southern Ontario, Canada through New England south to Florida, and west to Minnesota, South Dakota, Kansas, and Texas. Look for this species along forest edges in woodland habitats.

Sources: Buck, M., Marshall, S.A. and Cheung D.K.B. 2008. "Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region," Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).
Eiseman, Charley and Noah Charney. 2010. Tracks & Signs of Insects and Other Invertebrates. Mechanicsburg, Pennslvania: Stockpole Books. 582 pp.
Krombein, Karl V., Paul D. Hurd, Jr., David R. Smith, and B.D. Burks. 1979. Catalog of Hymenoptera in America North of Mexico Volume 2. Washington, DC: Smithsonian Institution Press. pp. 1199-2209.
Krombein, Karl V. 1967. Trap-nesting Wasps and Bees: Life Histories, Nests, and Associates. Washington, DC: Smithsonian Press. 570 pp.

How to Catch a Leafroller Caterpillar (Video)

Solitary wasps are amazing creatures, and their hunting behavior is particularly interesting. While my wife and I were in western Massachusetts last month, I was privileged to witness a female mason wasp, Ancistrocerus unifasciatus, successfully capture a leafroller caterpillar. I also got parts of the drama on video.

The scene: A large suburban residential backyard in Athol, Massachusetts, specifically planted to attract all manner of pollinating insects. Natural habitat is mixed hardwood and conifer forest, that abuts the property where this episode took place. Western Massachusetts is an odd mix of suburban and rural, actually, and it is difficult not to characterize this particular property as a "farm."

The leading actress: Ancistrocerus unifasciatus is a mid-sized mason wasp in the family Vespidae, subfamily Eumeninae. Females have a forewing length of 9.5-12 millimeters, males a forewing length of 6.5-9 mm. Both genders are basically deep brown or black with few yellow markings on the face, antennae, base of the abdomen, and legs. Males have a large yellow patch on the face, females a couple of spots.

Male, from Illinois. Note hooked antennae

Only females do hunting and nest building. The species ranges throughout the eastern U.S. west to Iowa, Kansas, and Texas. It also occurs in southern Ontario and Quebec, and Prince Edward Island.

The victim: I honestly cannot verify the identity of the caterpillar in this case, but it is certainly a leafroller in the moth family Tortricidae, and *possibly* the species Archips purpurana, which has goldenrod as a known host plant (among several others).

Is it coming out yet?

The wasp did not pursue its prey the way I thought she would. It even took me a minute to ascertain that she was hunting. I figured she would simply tear open the rolled leaf, grab the caterpillar, and go. Apparently the silk-bound fortress is more impregnable than I imagined.

Maybe at this end?

What the wasp did instead was pure genius. She took advantage of the caterpillar's instinct to "eject" when it feels like its home will be compromised. The wasp ran to one end of the leaf roll, then walked back, vibrating her abdomen to entice the moth larva to jetison itself. Back and forth she ran, as this video shows.

Unfortunately, I did not keep the camera running through the entirety of the hunt, partly due to fatigue, but when I saw the wasp suddenly had the caterpillar in her jaws, I resumed the video in time to see her fly to a nearby leaf to finish stinging her prey into paralysis.

Normally, the caterpillar, if threatened, takes a flying leap out of the leaf roll, trailing a silken line that it will then use to climb back once danger has passed. Kind of the caterpillar version of bungy jumping. The wasp obviously exploits this tendency, and very effectively.

Finishing off her victim with more stings

So, what does the wasp do with the caterpillar? Where does she take it? Adult wasps typically feed on flower nectar, aphid waste ("honeydew"), fermenting tree sap, and/or other liquids high in carbohydrates to fuel their energetic activities, like flying. So, this morsel of protein is not something the wasp would eat. The caterpillar is instead intended for her larval offspring.

And away she goes!

Ancistrocerus unifasciatus likes to set up house in abandoned mud dauber nests, especially those of Sceliphron caementarium and Trypoxylon politum. The mason wasp caches several paralyzed caterpillars in one of those cells. She lays an egg in the cell, then erects a partition and begins filling another cell along the length of the original, larger cell made by the mud dauber.

The larval wasp that hatches then has a larder of fresh food to feed it. Eventually it spins a silken cocoon, and pupates inside. An adult wasp emerges weeks later and chews through the mud wall to freedom.

Sources: Buck, M., Marshall, S.A. and Cheung D.K.B. 2008. "Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region," Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).
Krombein, Karl V., Paul D. Hurd, Jr., David R. Smith, and B.D. Burks. 1979. Catalog of Hymenoptera in America North of Mexico Vol. 2. Washington, DC: Smithsonian Institution Press. 2209 pp.

Spider Wasp, Agenioideus humilis, Caught on Video

I am finally remembering to shoot video of interesting insect behavior when I'm presented with the opportunity. Please do not come to expect movies and clips as a regular part of this blog, but know that I am trying to get that kind of documentation. For example, I recently happened upon a female spider wasp, which I later identified as Agenioideus humilis, dragging an unidentified, comatose orbweaver down the rockwork on the exterior of an outbuilding in North Cheyenne Cañon park here in Colorado Springs, on June 27.

This is a small wasp, females ranging from 5.5-10.5 millimeters in body length (8 mm average), males even more diminutive at 4-9.5 millimeters (6.5 mm average). Both genders are dull black, with a dorsal white spot near the base of the tibia ("shin" segment) on the hind leg. The wings are clear, but with a dark edge and broad dark band on the front wing.

Agenioideus humilis ranges across the entire U.S. save for the northern Rockies, northern Great Plains, most of Minnesota, Wisconsin, and northern Michigan. Nowhere does it appear that this species is common, and it is scarce in collections. The wasp does not appear to feed on flower nectar or aphid honeydew, the favorite foods of most adult spider wasps in the family Pompilidae.

I almost missed seeing this female completely, as she had ducked behind a drainpipe running vertically down the building. The shadow cast by her and her prey is actually what caught my attention. Despite being startled by my approach, she maintained a grip on her spider victim and continued here zig-zag descent down the wall, as reflected in the video clip below.

Once she reached the ground, she deposited her burden and commenced grooming herself briefly. She then ran about a foot away, to the base of the building, where it appeared she had already started a nest burrow. This next clip shows her digging at warp speed, sand flying between her legs and behind her.

Prior records for this species show it will also nest in pre-existing cavities such as cracks and crevices in rocks or the walls of buildings. The single victim is paralyzed by the wasp's sting and hauled to a suitable location for....burial. The wasp lays a single egg on the spider, then covers her tracks by scraping soil over the nest entrance and compacting it with blows from her abdomen. She then departs to begin the process again.

While this wasp was actively engaged in nesting, another wasp lurked nearby, on the wall of the building. Initially, I thought this was some kind of parasitic wasp, but upon closer examination, it turned out to be a male of her own kind. He was substantially smaller and of considerably different body type than the female.

Male A. humilis

Prey records for Agenioideus humilis reflect that the preferred prey are orbweavers in the family Araneidae, with several different species represented: Acacesia hamata, Larinioides cornutus, and Araneus pegnia among them.

This spider wasp apparently favors woodland habitats with sandy soil, and indeed the landscape where I encountered this one was a mixed conifer (mostly pine) forest with Gambel's Oak, chokecherry, and other shrubs in the understory.

I rarely find wasps toting prey, but I hope the next time that I do I will have means to record the event. Keep your own camera handy, you never known when you will happen upon entomological drama.

Sources: Evans, Howard E. 1950. "A Taxonomic Study of the Nearctic Spider Wasps Belonging to the Tribe Pompilini (Hymenoptera: Pompilidae), Part I" Trans. Amer. Entomol. Soc. Vol. LXXV[75], pp. 133-270
Krombein, Karl V., Paul D. Hurd, Jr., David R. Smith, and B.D. Burks. 1979. Catalog of Hymenoptera in America North of Mexico Vol. 2. Washington, DC: Smithsonian Institution Press. 2209 pp.
Wasbauer, M.S. and L.S. Kimsey. 1985. "California Spider Wasps of the Subfamily Pompilinae (Hymenoptera: Pompilidae)," Bull. Calif. Insect Survey. Vol. 26. 130 pp.

Courting Robber Flies

It must be spring. Love is in the air, on twigs, on the ground....at least if you are watching insects. They are courting and mating everywhere. My last couple of outings afield on the plains here in eastern Colorado have given me the opportunity to witness some insect romance up close; and I remembered to use the video function on my camera, too.

Male Ablautus(?) robber fly with leafhopper prey

One particularly abundant insect in early spring is a small robber fly, family Asilidae, possibly in the genus Ablautus. Adults of this dipteran measure only about 6-7 millimeters, and they are sand-colored, so rather difficult to see. They prey on insects smaller than they are. The one in the image above has killed a leafhopper.

I discovered that the males are slightly smaller and more slender than females, with bright white hairs on their faces. Females have gold or ochre-colored hairs on their faces.

Female Ablautus(?) robber fly

Males are very energetic, and once engaged in courting a female, they are not easily frightened away. So, once I discerned there was a pair of the flies on the ground in front of me, I stopped and watched. This is the amazing result. The male alights near the stationary female, then flies and alights again, sometimes sidling into a different position. Eventually, he waves his front legs in front of her and rocks up and down. It is quite a display.

This next video is of a different pair of flies, perhaps a little farther along in the process, because it has an, uh...."happy ending." The male is the one with the smile on his face.

Many flies have elaborate courtship rituals, but asilids (robber flies) have some of the fanciest. I was lucky enough to also capture video of the aerial display of Heteropogon macerinus in Ohio a couple of years ago.

Robber fly "wedding photo"

I urge you to find your own examples of "bug love," and document them with your camera, even your smartphone. There are plenty of places to share the results online. Maybe your video will even go viral on YouTube. In any event, we stand to learn a good deal more about insect behavior through the efforts of curious citizen scientists.

Grand Theft Caterpillar (caught on video)

Parasitoid wasps, those species in which the female incapacitates its host, and often caches one or more victims in a burrow, mud nest, or natural cavity, are not above stealing prey from others of their own kind, rather than doing an honest day's hunting. Such was the case I captured recently on video, while watching a Podalonia cutworm hunter in my Colorado Springs neighborhood.

Walking a path through degraded shortgrass prairie habitat, I suddenly noticed this wasp, with her prey, in the middle of the trail. She may have been feeding on the caterpillar's hemolymph (blood), or just making sure the larva was properly paralyzed.

She was nearly motionless for some time, so it came as a bit of a shock when it became apparent she was at the very entrance of a burrow she had excavated before going hunting. Here, in the video clip below, she finishes opening the tunnel, then drags her prize underground. Notice she is a "puller," carrying "armloads" of soil out of the nest rather than scratching it out behind her in a fountain of sand like sand wasps do.

Emerging from the tunnel after burying the cutworm, the female wasp suddenly took flight. I heard a loud buzzing and noticed she was engaged in a literal knock-down drag-out battle with another female Podalonia. The tangle of wings, legs, and bodies persisted a surprisingly long time before the two separated.

I could not tell who the victor was, until a wasp dragged the caterpillar back out of the nest burrow. Clearly, the winner was the usurper, and she was now claiming her spoils.

What is revealing about the complex instincts of hunting wasps is how their internal "program" demands they follow a strict sequence of behaviors, regardless of circumstance. So, the wasp repeatedly stung the already-paralyzed caterpillar, as it would if it had hunted the larva instead of pilfering it from the other wasp.

This drama was playing out in mid afternoon, and I had to get back home to eat something, feed and walk the dog, and whatever other chores I had been neglecting. Consequently, I could not determine whether the thief had not yet excavated her own burrow. She deposited the caterpillar and scurried seemingly randomly before beginning to dig. Perhaps she was opening her own burrow, or digging a new one. She tried digging in another, nearby spot as well, but I had to leave before the whole situation played out completely.

When I left, the original wasp had returned, and the paralyzed caterpillar at the center of the robbery was, ironically, sitting equidistant from both wasps. For all I know, the honest wasp was able to reclaim her property.

Podalonia version of detente

Every day in the world of "bugwatching" is an adventure, and your likelihood of witnessing such captivating episodes increases the more time you are outdoors looking. Sure, there is a fair degree of luck involved, but I guarantee you will see and hear many amazing behaviors if you are the least bit alert.

Ammophila in Action

Here in Colorado Springs on July 16, 2013 I had the good fortune of encountering an adult female thread-waisted wasp, Ammophila procera, lugging a caterpillar to a burrow she had prepared previously. Even better, I remembered that my camera has the capability to take video.

I was taking pictures of a skipper butterfly when I caught a glimpse of something moving almost under my feet. It was the wasp hauling her prey through the tangled vegetation. Getting images is a challenge because if you are too far away you get little detail, but if you venture too close you disrupt the behavior if you don’t scare the wasp into abandoning its prey altogether. I have done the latter before and felt guilty afterwards.

I was initially intent on getting the still images, when I remembered I could also get video. That was the same moment the wasp took off at a breakneck pace, making it almost impossible to follow her. Her ability to run with such awkward cargo would put a human athlete to shame. Anyway, she eventually paused, propping her limp caterpillar victim in the crotch of a plant while she went off to explore parts unknown.

I patiently waited and, sure enough, she returned. Soon, she resumed her trek, eventually reaching a more open spot. She promptly dropped the caterpillar, removed a large clod or pebble that was blocking her burrow entrance, dove down, turned around, popped back up, grabbed the caterpillar, and in an instant there was no sign of either creature. Without knowing the location of the burrow entrance ahead of time, I did not stand a prayer of recording the action.

A short time passed, presumably while the wasp laid an egg on her victim, and then she appeared at the surface again. She quickly began closing the burrow, permanently, this time, and at last I was able to capture her energetic activities in moving pixels. The location of all this drama was close enough to an airport that the sound of arriving and departing aircraft overwhelmed much of the audio, but I managed to find a portion that was relatively quiet. Listen for the buzz of the wasp’s wing muscles as she works.

Since this encounter I have learned how to recognize when a wasp might have a burrow in a certain spot. If I walk by and startle a wasp, but it does not leave, there is high potential that she has a burrow in the immediate vicinity and I should back off slightly and watch where she goes. I managed to get video of another Ammophila and two Prionyx atratus later that same day I got this video.

You can improve your chances of capturing the behavior of solitary wasps by being observant of their behavior, and putting yourself in the appropriate habitat. Open areas with sandy soil are favored nesting sites for many different species of wasps. They are not aggressive insects, but instead intent on accomplishing the business of providing for their future offspring. Happy wasp-watching!

Robber Fly: Heteropogon macerinus

Happy “Fly Day Friday.” Robber flies in the family Asilidae have to be among the most compelling of all insects, as evidenced by the many professional and amateur entomologists who study them. They are diverse in appearance and behavior, and yet there is still much to be learned about them.

This past August I had occasion to visit southern Ohio, and in several places I found specimens of the species Heteropogon macerinus. They are not terribly large, about 10 millimeters long or so, and fairly drab in appearance as you can see from the images here. They are fairly easy to spot, however, because they tend to frequent forest edges where they habitually perch on the tips of twigs at about eye level.

Robber flies like these remind one of flycatchers in the world of birds. They survey the world from their perch, cocking their head this way and that when an insect passes by. Should a flying bug seem to be a potential meal, the robber fly dashes out, grabs its victim, and returns to its perch to feed.

Robber flies have piercing-sucking mouthparts much like a mosquito, but shorter, stouter, and used to prey on other insects, not to feed on the blood of vertebrates. What is visible to us is the sheath that houses the stylets that do the actual piercing, so while it appears that a robber fly has a thick, knife-like beak, the killing and feeding machinery is virtually hair-like.

Asilids have an uncanny ability to find the weak spots in another insect’s armor, and quickly thrust their mouthparts into those areas. Some species go for the “neck,” stabbing through the thin and flexible exoskeleton that joins the head and thorax. Some are able to drive their stylets into the membranes between abdominal segments; or in the seams between various segments of the thorax as this H. macerinus has apparently done to a winged ant in the image below.

What really got my attention was a courting pair of Heteropogon macerinus that my wife and I spotted at the edge of a cemetery in Lynx, Ohio on August 25, 2013. The tarsi (“feet”) on the front legs of male Heteropogon species are at least slightly decorated with ornamental setae (“hairs”), and he uses these “bracelets” to full advantage. Norm Lavers, on his own robber fly website, describes their behavior most eloquently:

”If you are lucky enough to see the courtship, that will put the identification out of doubt….they all seem to do it the same way. The female makes herself visible by sitting on a twig usually rather high in the air, on the top of a sapling or tall bush. The male hovers before her, his hind legs out wide to the side, perhaps to show off the red coloring. The female responds by throwing up her hind legs (whether that means yes or no I don't know). If the male is allowed to get close enough, he begins stroking her eyeballs with his front claws while he is still hovering, a delicate operation, one presumes. If she likes him, she will eventually let him sit down beside her, where after a while one thing leads to another.”

Fortunately, another person in our party remarked that it would be wonderful to have a video of the aerial dance we were watching there in Ohio, and I remembered my camera has video capabilities. Here is the resulting….pixelage?

Is it any wonder why entomologists become enamored with asilids? The life history of the majority of species remains a mystery. The larval stage of those few that are known seem to be external parasites of beetle grubs, or the larvae of other insects. Your own observations could yield vital new information as to predator-prey relationships, and/or larval hosts.

I have yet to find any place in North America that does not have a pretty diverse assemblage of robber flies, so I challenge you to go looking, even in your own backyard. I will also bet you are likely to get addicted to these charismatic flies once you find them.

Sources: Hull, Frank M. 1962. Robber Flies of the World: The Genera of the Family Asilidae. Washington, DC: Smithsonian Institution Bulletin 224, Parts 1 and 2. 907 pp.
Lavers, Norman. 2007. “Asilidae: Stenopogoninae,” The Robber Flies of Crowley’s Ridge, Arkansas.
Preston-Mafham, Rod and Ken. 1993. The Encyclopedia of Land Invertebrate Behavior. Cambridge, MA: The MIT Press. 320 pp.
Raney, Herschel. 2009. “Heteropogon Page,” Random Acts of Nature.

Caught on Video: Prionyx atratus

I have been neglectful in exploiting my camera’s ability to shoot video as well as still images, until this year. I use a Canon PowerShot SX10 IS, and it does a nice job delivering the quality still images you see here on my blog. I am surprised by the detail I can get in video, too, perfect for documenting insects in action, with all their odd behaviors. One of my first subjects was a thread-waisted wasp, Prionyx atratus. Actually, I know I took video of at least two different females, both in the process of stocking their underground burrows with paralyzed grasshoppers.

July 16, 2013 was, for whatever reason, my lucky day to find several wasps engaged in nesting behavior. Up the street from our townhouse here in Colorado Springs is a vast open area cut by Sand Creek, a mostly dry riverbed or “arroyo,” and the surrounding soil is likewise sandy and very hospitable to burrowing insects of all sorts. Many “social trails” weave throughout the vacant, degraded shortgrass prairie, and it was in these trails that Prionyx atratus were nesting.

Normally, wasps resting on the ground are quick to fly far away at your approach, so I was confused as to why this one wasp was not eager to make an exit. Instead, it was persistent in running around my feet. I backed off and noticed freshly-excavated sand at the mouth of a small hole. I watched, and sure enough, the female wasp made her way back to her construction site. I shot many still pictures before I even thought to try video, so she was nearly finished opening the nest when I shot the following clip.

Notice how she “pulls” loads of soil out of the burrow, using her front legs. This is in contrast to other wasps that actively kick sand out behind them (Bembix “sand wasps” for example).

Prionyx atratus, like most members of the genus, dig nest burrows after obtaining prey. After securing prey, they leave their paralyzed victim a good distance away from where they begin digging, perhaps minimizing the opportunity for parasites like the tiny “satellite flies” you can see in the video that stake out a nest and wait for an opportunity to lay their own eggs (satellite flies actually “larviposit,” laying tiny, live larvae) on the wasp’s prey.

What surprised me was the speed with which the wasp retrieved her prey and hauled it head first down into the nest. I only managed this still shot.

Later, I came across a second wasp, and this time I did manage to capture her retrieving her prey. She still nearly outran my ability to keep up with her through the lens. Keep in mind, too, that grasshoppers are not lightweight insects. She has no problem trucking the creature overland despite its size and weight. I imagine that feat would be comparable to a human carrying a sofa in their arms and teeth, holding the couch out in front of them. And then running with it.

Prionyx closes her nest as carefully as she digs it, packing the loose soil into the tunnel for at least a centimeter, then obliterating all evidence of her labors on the surface before flying off to start another nest elsewhere. Here is a short clip of the closing process.

This species is a stocky animal not easily confused with similar wasps given a good look. The body is relatively short, the abdomen not extending beyond the wingtips when the wasp is at rest. The legs are relatively short and very spiny, more so than in other sphecid wasps. The abdomen is nearly spherical, not oval or elongate like most other wasps. This species is entirely black, females with silvery or gold faces, owing to appressed, reflective scales. Females average 15 millimeters in body length, males 12 millimeters. Their stocky form makes the look substantially larger.

Look for this insect across virtually the entire U.S. and southwest Canada (British Columbia and Saskatchewan near the border). Take heed if a wasp sticks around in your presence, she may have a burrow close by.

Sources: Bohart, R.M. and A.S. Menke. 1976. Sphecid Wasps of the World. Berkeley: University of California Press. 695 pp.
Pickering, John, et al. 2013. Discover Life.

Wasp Wednesday: Audition Video

I had the privilege of auditioning for a pool of new talent with the BBC Natural History Unit back in December of 2008. They wanted a demo DVD, so I had to enlist some help. I decided I would use grass-carrier wasps of the genus Isodontia, family Sphecidae, as my subject. The result is shown below.

A huge amount of thanks goes to Kirk Sellinger of Kalypsis Productions. Kirk helped me out on a moment's notice, charged reasonable rates, and shared a few tricks of the production trade. When he isn't working with minor clients like me, Kirk joins National Geographic tours documenting both the natural history and the guests, making DVDs available to the guests at the end of the expedition.

Nothing became of this particular audition for the BBC, but they were most gracious. I would very much like to make a living interpreting insect and spider natural history through all types of media, regardless of whether I am in front of the camera or not. Watching myself in this video I might actually prefer to be behind the scenes. I welcome inquiries from those who produce nature documentaries, or referrals to production companies and others in that business.

I have appeared on television before, locally (at the "Bug Fest" at the Arkansas Museum of Discovery in Little Rock, July, 2000) nationally (a guest on Donahue in February, 1989 for a discussion on children of divorce), and syndicated (Make Peace With Nature in the 1990s). I have also performed stand-up comedy for a live audience at the end of a comedy workshop.

Since I will be out of my current part-time job come May of this year, I figure I better get started on my next move. Creative enterprises really are "my thing," and I look forward to collaborating with like minds. Oh, and I’ll be back next week with a bit more on Isodontia. Thanks.