Wasp Wednesday: Chirotica

I never expect to encounter wasps in the middle of December, but then I also don’t go out looking for them at that time of year. A trip to the Sabino Canyon Recreation Area north of Tucson on December 19 has me re-thinking that assumption. I was surprised by the number and diversity of wasps I saw. Among the more interesting was an ichneumon wasp I later identified as belonging to the genus Chirotica.

Fred Heath, a volunteer naturalist at Sabino Canyon, had invited me along for a short hike in the late morning and early afternoon. He knows the area very well and was able to point out everything from plants to puffballs. On a willow tree full of bagworms (moth family Psychidae), a flash of movement caught my eye. A very elegant-looking ichneumon wasp was exploring one of the branches of the willow.

Ichneumons are notoriously quick to fly at the slightest movement, so I did not expect this wasp to stick around. Much to my surprise it simply continued its searching behavior, allowing me a couple images with my camera before it departed. What was this female looking for?

It turns out that the four North American species of Chirotica are parasites of….bagworms! It all made sense, and a series of images on the website Bugguide.net even show one of these wasps investigating a bagworm cocoon.

The “stinger” on my specimen is actually the female’s egg-laying organ, called an ovipositor. She does not use this structure as a weapon in self-defense and so is harmless to inquisitive people like me. Not that I could have caught her by hand anyway.

Anyone with an infestation of bagworms would likely welcome more of these wasps, but I honestly have no idea just how common (or scarce) they are. You can learn about the known distribution of our four species by using the Database of Hymenoptera in America North of Mexico. Bob Carlson, an expert on ichneumon wasps who is now retired from the National Museum of Natural History (Smithsonian) put together that part of the database.

Ichneumons are among the most diverse group of insects on the planet, so even an “armchair entomologist” can make significant contributions to science by documenting specimens through collection and imaging, but especially through rearing the wasps from host insects like butterfly and moth caterpillars.

Pygmy Mole Crickets

I know! What the heck is a “pygmy mole cricket?” Well, they are actually more akin to short-horned grasshoppers than mole crickets. I have known about them for some time, but finally saw two “in the wild” in the Sabino Canyon Recreation Area last Sunday, December 19.

The family Tridactylidae occurs on all the major continents except Antarctica, but most species are apparently tropical. There are only two species currently recognized in North America, and the one I encountered is likely Neotridactylus apicalis, the “Larger Pygmy Mole Cricket.” That species ranges from extreme southern Ontario east to Massachusetts, south to Florida, and west to southern California.

At about the size of a grain of rice (ok, from 5.5-10 mm), they are not very noticeable. Couple that with their habit of tunneling under the sand along the margins of streams, rivers, ponds and lakes, and it is no wonder they are not more familiar to naturalists. They move rather slowly, or at least this pair did as they crept up the surface of a streamside boulder. The hind legs of these insects are positively enormous, and the hind femora alone usually conceal the folded wings of the adults. The front wings are leathery and reduced to short stubs, while the membranous, pleated hind wings extend just beyond the abdomen when folded.

I was pleased that these individual specimens were so tolerant of a close approach with my camera (though I wished for a really good macro lens), because when they finally did decide to jump….Game over! They seemed to disappear into thin air. There was certainly no finding them again.

The physics of these jumps is remarkable, as revealed in the abstract for ”Jumping Mechanisms and Performance of Pygmy Mole Crickets” in the Journal of Experimental Biology, 2010 Jul 15;213(Pt 14):2386-98, by M. Burrows and M. D. Picker. Were a human even capable of such a feat, he would likely pass out from the G-force alone.

Pygmy mole crickets, which are also known as pygmy sand crickets or pygmy mole grasshoppers, apparently ingest sand particles and whatever algae and other organic matter adheres to them. Their subterranean burrows extend 2-3 centimeters below the surface, and females create brood chambers at the bottom of their tunnels.

Do keep an eye out for these little wonders. You are likely to find other insects in the same habitats, like the grouse locusts I’ll discuss in the next week or two. Happy hunting.

Wasp Wednesday: Campsomeris

I could never have imagined that I would confront another mystery wasp in the middle of December, but there it was: an e-mail from a friend describing what I knew (even in the absence of an image) was a species of wasp that had been recorded only recently in Arizona, and far closer to the Mexican border than in the Sabino Canyon Recreation Area where my friend’s sighting took place.

Fred Heath is an outstanding naturalist, author of the Introduction to Southern California Butterflies, and a member of the Sabino Canyon Volunteer Naturalists. On a visit to the area on Tuesday, December 14, he and others spied a male specimen of Campsomeris ephippium on blooming flowers of Desert Lavender (Hyptis emoryi). Fred didn’t get an image, but this wasp is so conspicuous and distinctive that it didn’t matter.

Fred posted a message on the e-mail list for the Sabino Canyon Volunteer Naturalists, sparking David Lazaroff, a founder of the SCVN, to go looking himself, camera in hand. The above image is used with David’s permission, and what a great picture it is. The long antennae, relatively slender body, and “pseudostinger” at the posterior of the abdomen reveal the gender of this specimen. Females, more robust with shorter antennae, have the real deal: a retractable stinger used to subdue the scarab beetle grubs that are the hosts for its larval offspring.

I would not have known what this was had it not been for this image from the spring of 2009. Up until that time, Campsomeris ephippium was known only from south Texas, and south to Ecuador.

Fred Heath and I went back to Sabino Canyon on Sunday, December 19, but failed to find the beast. Ironically, we did manage to spot a few males of the common local species, Campsomeris tolteca. They were hungrily feeding on the nectar of Coreocarpus arizonicus (Little Lemonhead) beside Queen butterflies and Mexican Yellows (also butterflies).

Campsomeris wasps belong to the family Scoliidae, all of which are known parasitoids of scarab beetle grubs. A parasitoid is a parasite that invariably kills its host. Female scoliids, with their heavy, spiny legs, dig up a scarab grub, sting it into brief paralysis, and then lay a single egg on the beetle larva. Then the wasp leaves the scene. The grub eventually regains consciousness and control over its motor skills (such as they are), resuming its underground existence feeding on the roots of plants. Meanwhile, the wasp egg hatches and the wasp larva begins feeding as an external parasite of the beetle grub.

I hope to eventually find more specimens of Campsomeris ephippium, and females of some of our other scoliid species here in Arizona, but I certainly enjoy the pleasure of the hunt regardless of the outcome. Special thanks to Fred Heath for allowing me to join him in the great outdoors. Thanks again to David Lazaroff for use of his fine image.

Wasp Wednesday: Mellinus

It never fails that just when I think I’ve seen it all I get surprised by some “new” insect. That happened on September 5, 2009, when I photographed a small wasp carrying a fly. Surely that must be a species in the Crabronini tribe, I told myself. I was dumbfounded when I downloaded the image and realized it was nothing I was already familiar with. Detective work ensued.

I posted the image above to Bugguide.net in hopes that another wasp expert might recognize it. Possible identifications were offered, but none of the suspects matched in terms of either morphology or prey selection. The mystery deepened.

I next went to my good friend and mentor Arnold Menke, a hymenopterist retired from the USDA Agricultural Research Service at the National Museum of Natural History. He literally wrote the book (Sphecid Wasps of the World) on the larger group of wasps that my specimen belongs in. Arnold also enlisted the help of Woj Pulawski at the California Academy of Sciences. We were conducting our correspondence over e-mail.

Meanwhile, my own continued research led me to believe that I had imaged a female Mellinus bipunctatus. I found images of other species in that genus carrying flies in a similar manner; and a close look at my image seemed to show that the wasp has a petiolate (“stalked”) abdomen, a character not shared by other fly predators of similar size (8-10 millimeters).

Arnold was initially unconvinced, believing it to be in a different subfamily. I had to agree, except for the fly prey factor. I created a guide page back on Bugguide for the genus Mellinus and moved my image there, adding my suggestion for the species. That coincided with a visit to Bugguide by Matthias Buck at the Royal Alberta Museum in Edmonton. He was delighted because Mellinus bipunctatus is a rarely-seen species.

Back in Arizona this year, I imaged another species of Mellinus while photographing small blow flies on some scat at the edge of Sabino Creek in the Sabino Canyon Recreation Area on April 13, 2010 at about 1 PM. Like pigeons reacting to a falcon, all the flies flew when the wasp alighted.

This image was yet another challenge, and Arnold sent me a couple reprints on the genus this time, one of which he co-authored. I also posted a link to my image on the professional entomology listserv I subscribe to, and received positive responses from Doug Yanega at UC Riverside, and James R. Wiley at the Florida State Collection of Arthropods. Doug suggested there was a possibility it was a new species given how uncommon these wasps are. Jim Wiley suggested the species M. imperialis, which was supported by Matthias Buck and also by Carl Olson, Associate Curator of Entomology at the University of Arizona. Carl found a specimen collected by Richard Bailowitz at Organ Pipe National Monument in 1987.

I went from the exhilaration of a potential new species to a possible state record, to not even a county record (dang western states with those huge counties…grumble, grumble). Ah, well, I know Rich and I’m happy that he got the first Arizona record.

Oh, you want to know something about the biology of these wasps? Virtually all we know comes from observations of the European species M. arvensis which is oddly common. These are “digger” wasps, excavating burrows in sandy soil, often in the company of other members of their species. The burrows extend 30-50 centimeters underground, terminating in one to ten individual cells. Four to nine paralyzed flies are provisioned in each cell, an egg laid on the last victim. The cells are closed with an earthen plug when finished, but the entrance to the main tunnel is left open while the female hunts.

The wasps hunt mostly in the vicinity of fresh manure, with males staking out territories there and intercepting females to mate with them. Observers note that the females stalk their prey in feline fashion, slowly creeping up behind an unsuspecting fly, then pouncing and pinning the fly’s wings while stinging it underneath its body. Once the prey is subdued, the wasp turns it over, grabs the fly by its mouthparts, and flies off.

Given that the bulk of the prey taken by Mellinus are muscoid flies (house flies and their kin), it is a shame the wasps are not more plentiful. They could be employed as biological controls of such “filth flies,” thereby improving rural sanitation.

Special thanks to all of those mentioned above, plus Julieta Bramblia who enlisted Jim Wiley’s help on my behalf. Entomologists rarely work alone, and we are privileged to have so many helpful colleagues.

Wasp Wednesday: Ammophila wrightii

Ok, I couldn’t resist writing about one more species in the genus Ammophila, if only because it represents a distinct pair of species that differs considerably from other members of their species group. Ammophila wrightii, and its relative A. formicoides, are mimics of ants.

I was fortunate to find this specimen nectaring on flowers of Burroweed (Isocoma tenuisecta) at the Arizona Sonora Desert Museum just west of Tucson on the afternoon of September 26, 2010. One rarely sees this insect on flowers. Females are usually actively crawling on the ground in the manner of harvester ants. They are easily mistaken for those social insects and thus frequently overlooked.

This is one of the smaller species of Ammophila (under 20 mm), and colored almost uniformly reddish brown. The species ranges from California and Nevada east to northern Nebraska and south to at least the Mexican border. There is one record from north-central Oregon. Oddly, most western specimens have three submarginal cells in the front wing while specimens from the eastern portion of its range have only two submarginal cells. Why the extra wing vein in some specimens remains a mystery. Both A. wrightii and A. formicoides also have a low, flattened pronotal collar (base of the “neck”). It is hard to believe, but both species are in the same species group as the gargantuan Ammophila procera!

Ammophila wrightii exhibits at least one rather primitive behavioral characteristic: The nest burrow is excavated after a prey item is collected, instead of beforehand. Burrows are vertical in orientation, and only inchworm caterpillars from the moth family Geometridae are recorded as hosts.

Not a great deal of field observations on this species have been recorded since C. H. Hicks published his in the journal Psyche in 1934. That was back when the species went by the name Sphex wrightii. Obviously, there is room for improvement. Go forth my friends, and seek your fortune of knowledge.

Special thanks to my friend and mentor Arnold Menke who identified my images.

Chiricahua Whites

Mary Klinkel, one of the volunteers for the Butterfly Magic display at the Tucson Botanical Gardens, invited me to join her in her quest to find a female Chiricahua White butterfly, Neophasia terlooii, in Madera Canyon on November 17. I eagerly accepted since I had never seen this species myself. The day was warm and clear, and we saw many butterflies and other insects.

We drove to the very end of the road and struck out on the trail at around 11:30 AM. Walking up the dry streambed we eventually encountered a trickle of water, and insects seemed to appear instantly, out of thin air. Among them was a lone male Chiricahua White. He quickly vanished from view, however, actively crawling into the leaf litter to reach the water underneath. I approached cautiously, and after several minutes succeeded in spying the sneaky devil.

The Chiricahua White is restricted in its geographic distribution to the isolated “sky islands” of southeast Arizona in the U.S., but also occurs in Mexico. Many of you are probably more familiar with its cousin, the Pine White, Neophasia menapia. The Pine White ranges from southern British Columbia south to California and northern Arizona, east to the Rocky Mountains. The caterpillars of both species feed on conifers, the Chiricahuan White apparently restricted to Ponderosa Pine and Engelmann Spruce.

There are two generations of the Chiricahuan White, one in early summer and one in autumn. The fall population seems to be much larger than the summer population. Males tend to outnumber females, which is normally the case in most insects. How do you tell the genders apart, though, and why was Mary so anxious to find a female?

Many species of butterflies exhibit “sexual dimorphism,” whereby males and females may appear radically different in appearance. Color, size, and even wing shape can vary in these cases. Females of the Chiricahuan White are, of all things, Halloween orange in color, with black wing veins.

I was lucky to see this tattered female (above) alight along the edge of the stream, where she remained while I called to Mary. Mary worked her way back down the trail and then stalked the butterfly with camera in hand. Eventually, she was able to gently coax the creature onto her finger. It was a real Kodak moment and a thrill for Mary.

We managed to find one more male on the way back down the trail. He was in perfect condition but seemed to fly clumsily, becoming tangled among grassblades before finally extricating himself and settling on this rock. I suspect that many specimens of this species simply drown in attempts to drink.

NOTE: This species is also known as the “Mexican Pine White,” with alternate spellings, or misspellings of the species name: terlooti and terlootii. Another excellent account of this species can be found at the ”Firefly Forest” website.

Wasp Wednesday: Ammophila nigricans

We’re going into overtime on “Ammophila Month,” so we can conclude with what may be the most elegant and impressive of all the eastern species in this genus: A. nigricans. This species is easily as large as A. procera, but readily identified by the lack of silver stripes on the thorax, the overall deep blue-black body with red on the abdomen, and the black wings.

I was fortunate enough to encounter this particular specimen around 5:00 PM on July 5, 2009 in South Deerfield, Massachusetts. She was in the process of finding a place to settle in for the night and was quite tolerant of my photographic activities. This is often the best time to look for Ammophila wasps in general, because of this “sleeping” behavior.

The wasps will grip a grass stem or twig with their jaws, then prop their slender bodies at about a forty-five degree angle away from their perch. It doesn’t look very comfortable, but this stiff posture appears to suit the wasps just fine. You can sometimes find several species of Ammophila in the same general vicinity as they bed down at dusk. There are certainly often several individuals of the same species in close proximity, as in the image below of an unidentified species.

When they are awake, females of Ammophila nigricans are all business. Each wasp digs a vertical or angled burrow in clayey or sandy soil, terminating in a horizontal chamber at the bottom. Once the nest is excavated, it is off to find a large caterpillar. Known hosts include the larvae of underwing moths (Catocala spp.), the locust underwing (Euparthenos nubilis), and zale moths (genus Zale). Those are hefty caterpillars, but then they are destined to feed the larva of a very robust wasp. This YouTube video may or may not depict A. nigricans, but the searching behavior must be very similar at the least. The female wasp is not likely to locate a caterpillar based on movement or color, as the caterpillars are very cryptic and usually resting stock still, feeding at night to avoid predators like the wasp. So, she must find her prey by touch.

I hope you have enjoyed this introduction to this genus of wasps, and that you are excited to find specimens of your own once the warm weather returns to your location. Meanwhile, feel free to share your past observations here. Happy holidays to you!

Wasp Wednesday: Ammophila aberti

One of the most beautiful species of thread-waisted wasps is Ammophila aberti, found commonly here in southern Arizona. It actually ranges throughout western North America, east as far as Iowa, and south into Mexico. These sleek, silvery wasps are a little larger than the average Ammophila, approaching the length of A. procera, but not nearly as robust.

I was fortunate enough to come across a fairly large nesting aggregation of this species at Ft. Lowell Park in east Tucson on May 11, 2009. The female wasps were digging in a very flat area with hard, baked soil. They would literally take bites out of the earth in order to excavate their nests. Despite the abundance of wasps, it was still a challenge to get images of them. The wasps would dig a bit, fly up, settle again, and repeat the process. Consequently, I had many images with no wasp in sight!

It turns out that the nesting behavior of Ammophila aberti has been well documented. One study revealed that females may initiate more than one nest at a time. Some had simultaneously started eight different burrows, up to a dozen for one ambitious specimen. Few of the nests were finished, however. Could they be creating “dummy” nests designed to confuse parasites like velvet ants that will dig open the nests of their hosts? That would be an ingenious ploy if so.

It may also take a female wasp a long time to furnish food for its offspring. A single egg is laid on the first caterpillar to be stored in the cell at the end of the vertical or angled burrow. By the time the last caterpillar is hunted, the larva from that egg may be reaching maturity. This has been interpreted by some researchers as progressive or “delayed” provisioning, feeding the larva as it develops, but clearly this is not the case. It may simply take some female wasps longer to find a full complement of caterpillars. Also, prolonged inclement weather may delay hunting activities for the females. Lastly, temporary scarcity of prey may delay the ability of the females to find caterpillars.

Ammophila aberti might be considered something of a generalist in that it uses a wide variety of Lepidoptera species in provisioning its nests. The study cited above recorded caterpillars from five different families of moths and butterflies (and skippers) used by this wasp: Geometridae, Noctuidae, Pyralidae, Hesperiidae, and Pieridae. An average of about six caterpillars per nest was the norm for the Colorado study of this species.

Another trait exhibited by this species is prey-stealing from other wasps in the nesting aggregation. A female returning to her nest is vulnerable to robbery since she must put down her caterpillar catch to open the temporary plug on her burrow. She may be attacked by one or more others of her kind that try to wrest the caterpillar from her. The hijacking is frequently successful. Further, some wasps may actually dig open the nest of another wasp and pilfer the paralyzed cache, though this is a rarer phenomenon.

As is the case with most other fossorial (burrowing) wasps, satellite flies (Sarcophagidae: Miltogramminae) are a constant threat to parasitize the nest. Interestingly, I observed another potential parasite in the form of a bee fly, Thyridanthrax sp. The female flies were hovering over the open nests of the wasps, lobbing eggs down into the tunnels in the manner of a jet bomber. Thanks to Joel Kits for making the identification from the above image, originally published on Bugguide.net.

Clearly, there is still much to be learned about this, and the vast majority of other species of solitary wasps. So, next summer, resolve to get out and make your own observations. You are almost guaranteed of making groundbreaking contributions to our collective knowledge. Meanwhile, have a very happy Thanksgiving holiday. Good luck provisioning your table with things more appetizing (and hearty) than caterpillars 

Wasp Wednesday: Ammophila pictipennis

One of the most common, and most handsome members of the genus Ammophila east of the Rockies (and south to Mexico City) is A. pictipennis. It is black in color, with red on the abdomen, and the black areas have metallic blue reflections in the right light. The wings are orange or yellow. The orange wings and lack of any silver bars on the side of the thorax help identify the species easily.

The individual above was imaged in Ocean City, New Jersey, fairly early on an overcast morning (October 19, 2010). It is in the classic “sleeping” posture adopted by Ammophila wasps during the night and inclement weather. The wasps grip a stem with their jaws, and prop their bodies at about a forty-five degree angle with their second and third pairs of legs. They often roost in loose clusters, jockeying for the best locations before settling down. This seems like odd behavior for supposedly solitary wasps. I once found a tight cluster of several Ammophila at Smith Rock State Park in Oregon. I initially thought it was a cluster of seeds or berries drooping from a short, erect plant.

When not resting, a female A. pictipennis is a busy insect. The species usually nests in sand, but will also excavate its shallow, vertical or nearly vertical burrow in hard-baked soil. The shaft is barely longer than the wasp herself, but ends in a nearly perpendicular cell that is spacious enough to accommodate the wasp and a lone caterpillar host. The specimen below was imaged at the Orange Airport in Orange, Massachusetts, September 7, 2009. She had brought a caterpillar to the vicinity of the burrow and was preparing to open it.

Known host caterpillars used by this species include mostly cutworms like the Armyworm, Mythimna unipucta, the Spotted Cutworm, Xestia c-nigrum, the Yellow-striped Armyworm, Spodoptera ornithogalli, and the Corn Earworm, Helicoverpa zea. There is at least one record of a caterpillar of the Common Sootywing (a skipper), Pholisora Catullus being used as prey.

Image above courtesy of Giff Beaton

The nesting behavior of this species is covered in detail by Phil and Nellie Rau in Wasp Studies Afield (Princeton University Press, 1918). Their interpretation of the wasps reveals at times perhaps more about the human observers than the reality of the instinctive processes going on in the insects. Still, it makes captivating reading and creates a real appreciation for the toiling labor of these creatures, as in the process of closing a nest:

”In her next selection she seems to be more particular. She goes here and yonder, pausing at clods and tiny pebbles, sometimes lifting them or turning them over. When finally she finds one that suits her fancy…she brings it in her mandibles and, grasping it firmly, she rubs, pounds and hammers down the dirt on the top of the hole until all traces of the fill are obliterated. When she has finished, we ourselves cannot discern the spot. Her task, so skillfully done, is now at an end; she throws her tool aside a few inches and flits away with an utterly careless air, as if she had forgotten all interest whatsoever in this place – and quite possibly she has. It is interesting to note that she cannot be persuaded to use this tool before the precise time for it. Once we tossed her a tiny pebble while she was yet busy grinding to pieces her clods with a pestle-and-mortar motion, but she only took it, without ado, and laid it back on her rubbish-heap, where an annoying bit of stick and a troublesome cinder had already been placed. Later on, when she was ready for her hammer, she went directly and, to our great delight, got our pebble which she had so stolidly spurned only a few minutes before….”

The image of an ungrateful hymenopteran is at least slightly amusing.

Subsequent research has shown that the “tool use” is simply the culmination of a series of instinctive behaviors. Still, one has to wonder if there was an individual “smart” wasp that increased the survival chances of her offspring by securing the closure of the nest burrow more thoroughly in this manner. Certainly, velvet ants are expert at detecting the subterranean nests of their hosts and digging them open, so such parasites must exert strong evolutionary pressure on the wasps to prevent break-ins.

A little more technical information is available on this page from Discover Life; and once again Dick Walton provides a wonderful online video that highlights the differences in nest excavation between A. pictipennis and A. procera. See if you can make your own observations of these fascinating species.

Caught on the Wing

In the nearly two years I have been taking digital images of insects, I have managed to capture, largely be accident, a few insects in flight. The resulting images reveal that insects are far from fragile, but definitely agile.

For every shot I get of an insect winging its way out of the picture frame, I get at least as many of flower without fly, or rock without wasp, the perches long since vacated by the insects, if that only means by a millisecond. And that happens when I’m trying to capture an image of a stationary insect!

unidentified fly

I can’t imagine trying to capture insects in flight on purpose, but that is exactly what some photographers have been able to do regularly. Stephen Dalton, and English naturalist and photographer, was perhaps the first to successfully document different insects in flight. His book Borne on the Wind (Reader’s Digest Press, 1975) remains a classic. Another Englishman, Dr. John Brakenbury, published Insects in Flight in 1992 (Blandford, a Cassell Imprint). Both men achieved their success under largely controlled circumstances, rather than outdoors in “the wild.” Still, the resulting images are breathtaking, and highly informative about the physics of insect flight.

I’m happy to simply communicate the fact that some insects *can* fly. Many people are unaware that most beetles can fly, so having an image like this one of a blister beetle (Lytta auriculata) taking off is helpful in illustrating that beneath its wing covers a beetle has membranous wings it uses to fly.

Sometimes I can even capture courtship behavior, like between these two Golden Longwing butterflies, Heliconius hecale, native to Central America but performing locally in “Butterfly Magic” at the Tucson Botanical Gardens.

Here, the male is making hovering overtures to a female that is unreceptive. She signals this by essentially mooning him. Yeah, I used to get that a lot, too, dude….

Most of the time, I get images of insects arriving at, or departing from, a flower, or other perch. Here are a few examples:

Eumenes bollii potter waspVilla bee flyAmmophila thread-waisted wasp

Insects are the undisputed evolutionary pioneers of animal flight, so it should come as no surprise that they are masters of aerial maneuvering, speed (at least for their size), and durability. Even the butterflies banging their way around indoor butterfly exhibits are barely slowed down despite what one might consider devastating damage to their wings.

We stand to prosper by continuing research into insect flight. How can a dragonfly manufacture turbulence, something deadly to a fixed-winged aircraft, and then use that turbulence to generate lift? Imagine the possibilities if we could duplicate the intricacies of insect wing movements in our own planes and helicopters. Maybe we, ourselves, could ultimately float like a butterfly….

Sleepy Orange, Eurema nicippe

Wasp Wednesday: Ammophila femurrubra

It probably became apparent several postings ago that the vast majority of insects have no “common name” in English. Today’s featured species, Ammophila femurrubra, is no exception. In fact, information on this handsome wasp seems to be lacking as well.

Little in the way of research funds and scientific attention is lavished on most insects unless they are of economic importance (read “pests”). You could argue that Ammophila thread-waisted wasps that prey on caterpillars in agricultural settings actually *are* economically important, but in a good way. Most administrators and bureaucrats that dole out research dollars don’t seem to be convinced, however. Consequently, any observations and documentation on such solitary wasps is usually executed voluntarily by “amateur entomologists” that in today’s language we call “citizen scientists.”

Chief among the pioneers to illuminate the biology of solitary wasps were George and Elizabeth Peckham, whose ground-breaking work Wasps, Social and Solitary (Archibald Constable and Company, Ltd., 1905) set the standard for their American followers. Phil and Nellie Rau, who published Wasp Studies Afield in 1918 (Princeton University Press), continued the Peckham’s legacy. There was also Edward G. Reinhard, author of The Witchery of Wasps (The Century Company, 1929); and John Crompton, who penned The Hunting Wasp (Houghton Mifflin Company, 1955). We also owe a debt of gratitude to the reigning champion of popular entomology, the late Howard Ensign Evans. His masterpiece Wasp Farm (Natural History Press, Doubleday, 1963) remains an inspiration to my own writing and love of the Hymenoptera. Still, Evans is best known for his book Life on a Little-Known Planet (Dutton, 1968), easily the best popular book on insects ever published.

So what does this have to do with Ammophila femurrubra? It means we need another Howard Evans to investigate the biology and behavior of this species. All I was able to determine in my research is that the species ranges in the “southwestern U.S.” How enlightening. My personal observations would tend to reinforce the idea that it is typical of the genus, even “sleeping” in the manner of other Ammophila. It is one of the more common species in urban Tucson, so perhaps it is more adaptable to habitat fragmentation than other species. At about 25 millimeters in length it is of average size for the genus, too.

As always, I encourage all of you to be observant and record your observations if possible. You really never know what you are adding to our collective body of knowledge.

Wasp Wednesday: Ammophila procera

I am declaring November as “Ammophila Month,” with the postings on Wednesdays dedicated to different species of this diverse genus of thread-waisted wasps in the family Sphecidae. There are over sixty species in the genus in North America. We’ll start with one of the most spectacular, Ammophila procera, which I was able to photograph near the lighthouse at Cape May Point State Park in New Jersey.

This is not a small wasp, females at least approaching two inches (25-38 mm according to the Bugguide.net page) in length. It ranges across the entire continent from southern Canada to Guatemala. This is the largest species in the eastern U.S. to sport the silver stripes on the side of the thorax, a hallmark of most members of the genus.

I was able to get very close to this female as she was nectaring on goldenrod blossoms, but that is typical of most species of Ammophila. They are solitary, and shy or gentle in nature. They are quite distracted while feeding on nectar, but otherwise very alert and quick to fly. Nesting females are very persistent, however, and if frightened away from a burrow they are excavating will return most of the time to finish it.

Females of Ammophila procera nest in compact sand, so finding this one at the beach on October 15 was not too surprising. The burrow varies from slanted to vertical and ends in a single cell. Once the burrow is completed, the wasp exits, covering the opening and making an orientation flight so she can find it again. Then, off she goes to find a caterpillar.

She will attack a large caterpillar, stinging it into paralysis and then lugging it back to the nest. She grips the caterpillar with her mandibles and middle legs in a manner that seems to render the prey rigid, allowing her to run in a pretty agile manner, all things considered. She can also fly with the caterpillar oriented beneath her body for maximum aerodynamic efficiency. To see one flying with a caterpillar is quite something. The caterpillar often contrasts greatly in color with the wasp, making for an absurd visual unless you know what is going on.

Known host caterpillars for A. procera include caterpillars of the Prominent Moth family Notodontidae such as the White-dotted Prominent Moth, Nadata gibbosa, the Variable Oakleaf Caterpillar, Heterocampa manteo, H. Astarte (no common name), the Morning-glory Prominent, Schizura ipomoeae, members of the genera Datana and Symmerista; and at least one record of the One-eyed Sphinx, Smerinthus cerisyi.

Despite its size and imposing nature, A. procera is not without its own enemies. Among its parasites are “satellite flies” in the family Sarcophagidae, especially Senotainia vigilans and Metopia laterallis. The female flies follow a prey-laden female wasp to her burrow and then look for a chance to lay their own “live” larvae at the mouth of her nest burrow.

You owe it to yourself to see these wasps in action, and I have just the thing to get you hooked on their amazing biology. Dick Walton has shot some amazing videos of this was which can be seen at his websiteDick Walton Natural History Services. The one for the species discussed even includes the satellite flies! Watch for their cameo appearance about midway through the clip.

Have a great week, friends, and remember to tune in again next Wednesday for another installment of “Ammophila Month.”

Holiday Gift Ideas

As I write this there are only 54 shopping days until Christmas. Time for my annual gift recommendations for your naturalist friends (or to add to your own wish list). I won’t even toot my own horn for the Kaufman Field Guide to Insects of North America. Here are three ideas that I am sure will please any “amateur” entomologist out there.

My good friend Daniel Marlos, who started up the website What’sThatBug.com now has a new book to add to his list of successes. The Curious World of Insects: The Bugman’s Guide to the Mysterious and Remarkable Lives of Things That Crawl, a Perigree Book (Penguin Group), has a decidedly whimsical, Victorian-era flavor, in part due to the historical, clip art style illustrations throughout.

Marlos is a visual artist whose interest in insects comes more from a pop culture perspective than an entomological one. Still, Daniel has become a trusted authority in a very short time. He knows Australian insects better than I do, in part because he gets many submissions to his website from that island continent. He is a professor of photography at Los Angeles City College, but is independent of an academic institution when it comes to entomology. This has allowed him to set his own standards for responses to his website users.

Here in his book, he spotlights the insects and related arthropods most frequently encountered and asked about. Daniel’s research skills are first rate, and he excels at interpreting the lives of “bugs” in a way that is both educational and entertaining. It has been my pleasure and delight to see Daniel’s website succeed beyond all expectations; and to see an entomologist and writer metamorphose from such humble beginnings.

Yet another gifted gentleman, Dr. Edward Eric Grissell (Eric to his friends and colleagues), has come out with a much-needed popular book about stinging insects. Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in Gardens, published by Timber Press in Portland, Oregon, is an outstanding treatment of this fascinating order of insects.

Grissell’s prose is complemented by the jaw-dropping images that illustrate the book. No other popular book still in print communicates the sheer diversity of bees, wasps, sawflies, ants, and related insects in such an eloquent and captivating fashion. This is not a field guide, but is easily the best overview of Hymenoptera for amateur naturalists. Many specimens will be identifiable from the images in this book, but the reader gets a complete understanding of the biology and ecology of the insects as well.

I can’t help but be amused by the endorsement of the book provided by another author, Amy Stewart, who concludes that “Eric Grissell will make a hymenopteran out of all of us.” I, for one, certainly hope not. I enjoy being a human being. Maybe she meant he’ll make a hymenopterist out of all of us.

My final recommendation is a different product that all of us can use: a wall calendar. The Xerces Society presents its 2011 North American Bee Calendar featuring fabulous images of, and pertinent information about, the many solitary bees that pollinate wildflowers and crops across the continent.

The image here shows the cover of the 2010 calendar, but I can hardly wait to get my hands on the new one. Besides getting a superb product, your purchase aids the premiere invertebrate conservation organization in the world.

Wasp Wednesday: Chelonus

Among the parasitic wasps, members of the family Braconidae are often very conspicuous. Most braconids are very similar to ichneumon wasps, and easily mistaken for them at first glance. Differences in wing venation and abdominal structure are the key to separating the two families. The subfamily Cheloninae is one of the more easily recognized because the abdomen appears to consist of only one segment.

The first three “urotergites” of these wasps are fused, meaning that what are normally individual segments on the dorsal (top) side of the abdomen are fused into essentially one plate that hides the remaining dorsal segmens. The ventral (underside) of the abdomen is at least slightly more normal in its segmentation.

The Cheloninae includes seven genera worldwide. The genus Chelonus alone contains approximately 139 species in North America north of Mexico. All are internal parasites of the larvae of Lepidoptera, especially the pyralid and tortricid moths.

The life cycle of chelonines is quite remarkable. Females use their hair-like ovipositor to insert an egg into the egg of the host. I initially thought that the wasp in these images was ovipositing into the flowerhead, but apparently it had detected the eggs of a host already embedded in this flower. Once the larval wasp hatches, things get really interesting.

The wasp larva remains in its first instar (the first larval stage that hatches from the egg) while the host caterpillar it is living inside of matures. It is not until the caterpillar spins a cocoon or otherwise prepares to pupate that the wasp larva resumes its own development, consuming the host in the process. Even more amazing, there is at least one documented instance of the host caterpillar’s life history being altered to the point that the caterpillar attempts to pupate earlier than normal. Theories on how the parasite might cause this interruption in the host’s normal life cycle are discussed in this 1985 article in the journal Physiological Entomology.

These are not large wasps, maybe 5 millimeters on average, but they are fairly robust and easy to spot on late summer and fall flowers like wild carrot. See if you can’t find some in your own neighborhood.

Boxelder Bugs Revisited

It is that time of year again! No, not Halloween. No, not elections (and which of those two is more scary, anyway?). It is Boxelder Bug season. I imaged this one a couple of weeks ago at the Rea Farm in Cape May, New Jersey:

Rather than repeat myself, I’ll kindly refer you to the blog I did last year as part of my ”Indoor Insects of Autumn” series. The other three parts covered the Western Conifer Seed Bug, Brown Marmorated Stink Bug, and Multicolored Asian Lady Beetle. See if you can’t find some of these in your own neck of the woods this week.