A Lady Beetle-Mimicking Cuckoo Bee and Its Host

Kleptoparasitic bee (Holcopasites calliopsidis) nectaring on fleabane Northfield, Minnesota – August 13, 2014

As winter suddenly tightens its grip on us here in Minnesota (it’s snowing outside as I write this, and cold), it’s the perfect time to sit back and do some reading and to reflect on this past summer’s encounters. This means more poetry, more desk work, and more blog posts.

On a recent visit to the college library to retrieve a book about the ecology of tropical bees, I found a slim pamphlet standing near it on the same shelf. Picking it up and opening it, I saw that it was a published lecture given April 22, 1970, at Utah State University by George Edward Bohart. Bohart was an internationally recognized expert on pollination biology and a professor at USU. (Interestingly, his brother, Richard M. Bohart, was another well known entomologist, founder and namesake of The Bohart Museum of Entomology at the University of Califonia, Davis.)

In his lecture, The Evolution of Parasitism among Bees, Bohart discusses the various bee families and the parasitic black sheep among them: from honey-robbing honey bees and resource-pillaging stingless bees to cuckoo bumble bees displacing rightful queens from established nests and myriad kleptoparasites stealing into nests of solitary bees and laying their eggs upon pollen stores not rightfully their own. The trickery involved in parasitism must be quite successful in the grand scheme of things given the abundance and variety of parasitic species. For example, Bohart points out that just among the bees “morphological evidence indicates that existing parasitic lines were derived at least 16 times from non-parasitic ancestors.” (emphasis mine) This lecture reminded me of the interesting parasitic bees I’d encountered, in particular the host prey pair discussed here.

In 2014, I encountered, for the first time, Holcopasites calliopsidis, a brightly colored but tiny parasitic bee that targets the mining bee Calliopsis andreniformis (a fact reflected in the species name of the parasite). At 5 mm in length, this bee is smaller than a grain of rice. A single photograph, mid August, taken as the bee nectared on fleabane (see photo above). I revisited these flowers many times that autumn and the following year and did not encounter this bee again.

This summer I had much better luck. One day in June I noticed a number of tiny bees at several patches of hard-packed, bare ground along the walking trails in the St Olaf Natural Lands. These turned out to be Beautiful Mining Bees, Calliopsis andreniformis. Again, grain-of-rice-sized, though perhaps a millimeter or two greater in length than the aforementioned species. On subsequent visits to the same locations, I was able to get very good photos of these small bees, both the females and the surprisingly different males, with their lemon-yellow legs, face and antennae. According to the description in The Bees in Your Backyard, almost all the bees of the genus Calliopsis are specialist pollinators. Unfortunately, I was unable to observe which particular plants Calliopsis andreniformis had been visiting at this location. (A photo on Bugguide by Heather Holm shows this species on Blue Vervain at a nearby location in Minnesota, and that’s one possibility here as well.)

Mining Bees (Calliopsis andreniformis) and mines Northfield, Minnesota – June 20, 2016
Mining Bee (Calliopsis andreniformis) Northfield, Minnesota – June 20, 2016
Mining Bee, male (Calliopsis andreniformis) Northfield, Minnesota – June 20, 2016

My good luck continued. Several times while watching the mining bees, Holcopasites calliopsidis showed up, snuffling the ground with their antennae, searching the nesting sites of their hosts. After I had several photographs of Holcopasites calliopsidis, I began to notice that this bee almost always kept its wings tucked under its abdomen. A curious and unique behavior. I haven’t been able to locate any explanation or even mention of this behavior. Considering the bee’s equally unusual colors and patterning, it seems at least plausible that the bee is mimicking the appearance of lady beetle larvae. I’ve included a photo by Katja Schulz of a Convergent Lady Beetle for comparison. If anyone has any alternative theories…I’d like to hear them.

Kleptoparasitic bee (Holcopasites calliopsidis) searching for host nests Northfield, Minnesota – June 20, 2016
Convergent Lady Beetle Larva Tuscon, Arizona – February 20, 2016. Photo by Katja Schulz , used by permission and creative commons license

Bohart, G. E. 1970. The Evolution of Parasitism among Bees. Utah State University.

King, S. 2016. A Photographic Guide to Some Common Wasps and Bees of Minnesota. Thistlewords Press.

Wilson, J.S. and O. Messinger Carril. 2016. The Bees in Your Backyard: A Guide to North America’s Bees. Princeton University Press.

Devious Sand Wasp

Nysson plagiatus
Devious Sand Wasp (Nysson plagiatus) – Minnesota – July 2016  

Obviously, the laws of the universe are such that the day after one finishes a guidebook to the wasps and bees the author will step outside and immediately see a species that is new and not included in the book. Actually, make that seven new species. In the weeks following the printing of the first edition of A Photographic Guide to Some Common Wasps and Bees of Minnesota, I’ve encountered seven species I hadn’t photographed before in the state. While I expected this would happen, I’m a little surprised at the abundance of previously overlooked species. But it’s a good thing. And I plan to add information here at Of Books and Bugs on these additional species. The first species (discussed below) probably doesn’t qualify as a “common” species.

Scientific name: Nysson plagiatus Cresson, 1882
Common name: Devious Sand Wasp (proposed)
Family: Crabronidae

This wasp showed up, a little conspicuously, among a densely congregated nesting site of Great Golden Digger Wasps (Sphex ichneumoneus). At first it stood at the entrance to one of the nests, then (as I leaned in for a closer look) this black and yellow wasp flew a few inches away to a leaf and proceeded to groom itself. In the moments that followed, several of the large sphex wasps arrived with prey, katydid nymphs, long and slender and pallid after being envenomed. Each paralyzed katydid is left unguarded for a brief period of time at the lip of their burrow while sphex disappears below to prepare the cell. She reappears a few seconds later, takes hold of the katydid antennae, and whisks the katydid below ground. I wonder, if Nysson plagiatus is quick enough, devious enough, might it not be able to secret an egg on the katydid during the brief interval that sphex spends underground?

While Nysson plagiatus hasn’t been confirmed as a brood parasite of the Great Golden Digger Wasps (this would require rearing one from the contents of one of the nests), the circumstantial evidence seems to be mounting. Most of the Nysson species are brood parasites of closely related wasps within their same family, the Crabronidae, so it’s a bit of a mystery why or how this wasp came to be a brood parasite of a wasp from an unrelated family, the Sphecidae. It’s thought that the jump was facilitated by the Orthoptera prey certain Crabronid hunting wasps have in common with this Sphecid hunting wasp.

Formerly placed in genus Synnevrus but recently moved to Nysson, its taxonomical status may not be settled. The yellow marking the full width of the first abdominal segment, differentiates Nysson plagiatus from Nysson aequalis which has a yellow marking only about half as wide.

Nysson plagiatus
Devious Sand Wasp (Nysson plagiatus) – Minnesota – July 2016

Wasps and Bees of Minnesota

I’m pleased to announce the publication of A Photographic Guide to Some Common Wasps and Bees of Minnesota. The last nine months I’ve been hard at work organizing, editing and writing this guidebook. It all began with the simple thought last October after the realization that I had photographed over one hundred species of wasps and bees…I know, I’ll put together a little book. Well, what at first seemed a straightforward and reasonable project, quickly consumed nine months. I hope it was time well spent, that the book will be useful and enjoyable.

In the end, I was able to include photos and descriptions for over 125 species (see sample page below). Also included are an introductory essay, a list of North American Hymenoptera families, and an index of scientific and common names. The book is available for purchase direct from me via PayPal at the book’s website or by sending a check for $28 (includes shipping) payable to Scott King to the 307 Oxford Street Northfield MN 55057. If you prefer a pdf for use on a tablet, that is available for $10. (176 pages, ISBN 978-1523208319)

A Photographic Guide to Some Common Wasps and Bees of Minnesota

The book is also available from Amazon.

Screen Shot 2016-07-07 at 10.44.15 PM

Wright Morris, Pecos Diamonds, and Hunting Wasps

Fire Sermon
After a mean-spirited coinhabitation of the flu, occupying the couch the way a bad stretch of weather occupies a week, needing something solid, lasting, earthbound to see me through some hours of misery, I took down an old hardcover from a nearby shelf. The book, Fire Sermon by Nebraskan novelist Wright Morris, would do.

The title made me think of T. S. Eliot and The Waste Land—it is after all the title of one of the sections of that poem. What I discovered, quickly, in the first few pages, was a humorous narrative of a boy, one Kermit Oelsligle, orphaned and living with a strange uncle, one Floyd Warner. The story and the style brought to mind The Christmas Story, that holiday film favorite based upon the writings of Jean Shepherd. This passage describing an employee at the local post office suffices for a flavor of Morris’s writing:

“He stands there, his pale face green in the shadow of his visor, the shirtsleeves turned back on his hairless arms. As many as eight or ten pens—ballpoints, felt points, etc.—fit into a plastic holder that protects his shirt pocket, although the only pen the boy has seen him use lies on the metal counter with several rubber stamps. Now and then he takes a puff of the cigarette he balances on the rim of the scales, right over one of the pouches, and there is no way to explain why the place hasn’t burnt down.”

These days when I read I’m always alert to allusions and comments referring to insects (as if spending hours and days looking for real insects is not enough!). Thus the following passage caught my entomological eye:

“He had sat down on a rock, and let his eyes rest on the small hole of some earth creature. Not so big as a prairie dog hole, or a mouse hole, but somewhat larger than most ant holes. Heaped around it, as in most cases, were the sand and pebbles kicked up out of the hole. A tiny volcano: that was how it would look in a photograph. He was struck by the color of one of the pebbles, and took a closer look. Separated from the others, in the palm of his hand, it looked very much like the stub of a pencil, only not so large. One end of it was sharpened to a very fine point, and it had six smooth polished sides. The other end was just a crude stump of dirt and sand, as if left unfinished.”

What the uncle, as a boy, held in his hand was a variety of quartz crystal known as a Pecos diamond. In a glass jar containing agates and crystals, inherited from my rockhound grandparents, are a few of these minute, crystalline pencil stubs, each no bigger than a tic-tac mint, sift their way to the bottom. And I wonder, now, having read this passage, if my grandparent’s adventures took them to the Pecos River country, and if these were authentic Pecos diamonds?

Obviously one of the great pleasures of reading is the synchronicity between reader and what’s written—the surprising way our memories bring living images up from the author’s printed words, the consentaneous way we are allowed to wander off the page and back again. So after wandering off in thought about my grandparents, I return and wander off in a new direction, this time in thought about the insects responsible for excavating these gems.

Mining bees seem the best match for a burrow shaped like a mini volcano, but there are a lot of contenders for insects that might excavate a hole the dimensions of which fall between that of the entrance to an ant hill and that of the entrance to a prairie dog burrow. Digger bees, cicadas, tiger beetles, come to mind. Or sand wasps that flick sand from their burrows through their legs like digging dogs. Or the hunting wasp that meticulously excavates, mouthful by mouthful, and discretely deposits her tailings some distance from the entrance to their burrow. If there were Pecos diamonds where I live, these wasps, like the thread-waisted wasp pictured below, would be likely excavators, hauling the buried gemstones up from the earth so they might glint in the sunlight of summer like tiny sparks of fire. I can’t help but think this would have been a wonderful mechanism for the reappearance of the magic ring in J. R. R. Tolkien’s middle earth saga, better perhaps than its surprising presence at the bottom of a stream.

Ammophila wasp – Northfield, Minnesota – September 23, 2014
Ammophila wasp – Northfield, Minnesota – September 23, 2014

Fire Sermon, to return to the novel, abruptly ends. After a long road trip in the uncle’s dilapidated car, driving from the California coast to the Nebraska plains (opposite the western movement of earlier generations), giving a lift to a couple of hitchhikers, the house that they have been journeying toward, that contains all the family possessions goes up in flames. And the fire, like that spoken of in the Buddhist Fire Sermon, liberates as it destroys. “Fire purifies” is what the hitchhiker, Joy, tells the boy in the book’s final sentence.

Jagged Ambush Bug

It’s been a long week, make that a long month. So many new tasks added to old obligations—construction of a new website for Red Dragonfly Press, publication of several new books (also for the press), new sports teams (for my daughter), and a couple of household wood-working projects—have left little time for visits to even nearby natural areas (let alone time to write about them). Yesterday, however, between fetching my daughter’s bike at the junior high and dinner, I found time for a quick hike at the Cannon River Wilderness Area.

At a pace near to running, it took me nearly fifteen minutes to breach the armpit-high ramparts of horse nettle that crowded the trail through ravine and river bottoms and break through to the good stuff, the wide-open fen and the hillside oak savanna. Catching my breath, I knelt alongside a section of sandy trail. A tiger beetle kicked sand out of a shallow burrow, either hunting or seeking shelter for the night. A bright, black-and-yellow beewolf arrived, its captured prey—a small, metallic bee, barely visible—slung beneath its belly. After remaining motionless for some time, the beewolf flew a few inches into a thicket of grass stems and began to excavate the entrance to its burrow. A satellite fly, gray and rather nondescript, tagged along behind the wasp, no doubt hoping to larviposit on the wasp’s prey before the wasp buries it. (This is probably one of the reasons beewolves rarely set down their prey, even while digging.) I now noticed a second wasp, a thread-waisted wasp. I watched as this wasp searched for a pebble, picked it up in her mandibles, then used it to seal the entrance of her burrow, tamping and pounding with the pebble before dropping it. After a few minutes of kicking sand around and the addition of several more pebbles, the burrow was sealed and camouflaged. The wasp, done with her day’s labors, flew a loose circle around the site, then departed.

Ready to move on, pleased to have been a small part of the landscape the departing wasp had memorized, I stood up. A line encountered recently in a poem by John Fuller came to mind. “But we so easy are still not at our ease.” The poem, ‘Aberporth,’ is a meditation upon a visit to a village on the west coast of Wales. I felt the poet’s admonishment. Here I was, ready to push on, when there was no need to push on. I could have sat down and continued watching over this small patch of sand until it was time to go. Instead, I turned and began to climb the prairie hills toward the oaks above, noting this failure to take my ease, but noting also that the grasses had lost much of their green since my visit earlier in the summer, that the year itself was speeding on as well. A few clumps of Gray Goldenrod still bloomed, adding dots of yellow to the rusty field. Sweet Everlasting bloomed in places as well and added a kind of green, dusty light to the hillside prairie, its pale florets raised like unlit candelabra. Taking a closer look at one of these flowers, I noticed a very strange bug.

Jagged Ambush Bug – Northfield, Minnesota – September 18, 2014
Jagged Ambush Bug – Northfield, Minnesota – September 18, 2014

Disruptively colored, its abdomen indented and spiky, this bug would be nearly invisible on a goldenrod flower, but on the white, bud-like everlasting flower, it stood out (instead of blending in). Still it was so small I couldn’t really appreciate how odd-looking it really was. Later, when I enlarged the photos, a chimera-like creature appeared on the computer screen, part Musk Ox, part mantid. Given such a fierce aspect at larger-than-life sizes—just look at those fiery eyes!—it’s best that its true-to-life dimensions remain at less than a centimeter in length.

This strange creature is a Jagged Ambush Bug. An apt name, I think, considering it’s basically a living trap for other insects attracted to the flowers on which it waits. Supposedly it’s even capable of capturing prey larger than itself. Fair warning, I guess, to those of us who wish to stop and smell the flowers, who insist on sticking our noses into the blooms.

Browne to Green

The Works of Sir Thomas Browne (1927 John Grant edition)
The Works of Sir Thomas Browne (1927 John Grant edition)

“Men that look upon my outside, perusing onely my condition, and fortunes, do erre in my altitude; for I am above Atlas his shoulders.”

Written by Sir Thomas Browne some centuries ago in his work Religio Medici, this sentence caught my attention when I first encountered it some years ago and it continues to fascinate me. The image of Atlas is curious. I always picture this god holding the earth on his shoulder, then inevitably wonder, not how heavy it must be, but where could he be standing. What is below Atlas his feet? And I admire the surprising use of the word “altitude.” But ultimately I suspect the main reason this sentence resides and rides along in memory is its sound, the syntax and cadence, especially that final phrase zeroing in on the shoulders.

Because my thoughts tend to dash off on wild tangents when reading, I sometimes (more often than I should care to admit) miss the point, and missing the point of this sentence by Browne would be especially embarrassing given that the sentence is about misreading, about errors in judgment. So let me change directions and get to the point of this blog entry, the point being that I did err in my estimation of the month of April.

Just as it’s possible to err in the estimation of a person’s “altitude,” it’s also possible to mistake the weather. By and large the general consensus of the weather throughout the month of April was that it was the pits, that it wasn’t fit for man nor beast. Perusing the conditions at my window or on the computer screen I too easily agreed. I was convinced spring wasn’t coming. The days linked together to form a malicious, unwelcome limbo. Each afternoon seemed to lose its way between melting ice and freezing water. However much I griped and kept from venturing out, the world beyond our snow-spattered windows found enough sunlight and warmth to get on about the business of changing seasons.

Judged by the list of first-of-the-year sightings—the first Chorus Frogs, the first Sandhill Cranes, the first mining bees, the first dragonflies, the first flowers, Scilla and Sanguinaria on the ground, Salix and Acer overhead —spring undoubtedly arrived in April. The ice went out. The grass turned green. Underneath the shroud of inclement weather, snow falling even to the final days of the month, the soil unthawed, the buds burst, and the insects awoke.

So far, May has been a lot easier to read.

Mining Bee (Andrena sp.) on Siberian Squill
Mining Bee (Andrena sp.) on Siberian Squill

What You Can Do For Bumble Bees

A Sting in the Tale by Dave Goulson

A Sting in the Tale: My Adventures with Bumblebees by Dave Goulson is due out in the United States from Picador at the end of April. By ordering a used copy of the English edition that was printed last year, I was able to jump ahead and read it in advance. Anyone with even a fleeting interest in native pollinators, in habitat loss, in agriculture, or in conservation will want to order this well-written, often-entertaining book. Combining memoir and natural history into a near perfect blend, Goulson gives us tales of tagging and tracking bumblebees, of grad students paired up with bumblebee sniffer dogs, of reintroducing locally extinct populations, all the while giving clear explanations of the science involved and the current research being done. If you’re already a bumble bee aficionado, who perhaps, like my daughter, enjoys watching and petting these big fuzzies while they visit summer flowers, I know you’ll enjoy this book immensely.

In one of the final chapters, Goulson admits to what must be a common frustration for scientists and researchers: “one might find out everything there is to know about bumblebees, and publish it for others to read in scientific journals, but only a handful of other scientists would read it and it would not result in there being one more bumblebee in the world.” Because of his knowledge and the need to get something done, Goulson founded the Bumblebee Conservation Trust, a non-profit charity “for the bumblebees” with the goal of raising awareness of endangered bumblebees and bumblebee conservation among farmers and land managers and gardeners, people in a position to improve habitat and increase the number of bumblebees in the world.

While most of the science and natural history in this book relates to the UK, much of it applies equally well to our North American bumble bees and their conservation needs. (One difference being the spelling of “bumble bee”–the convention seems to be two words here, but a single word in the UK. If we look back more than a century, we find “Humble-bee” in use by Ralph Waldo Emerson and Charles Darwin, because of the hum the bees make when flying). In North America, with one of our native species believed to be extinct, Franklin’s Bumble Bee (Bombus franklini), and numerous other species numbers in alarming decline, it’s obviously time to do something for our bumble bees as well.

Fortunately, many people here in the states have been hard at work protecting bumble bees for some time. The Xerces Society, which has been involved with protecting and raising awareness of native pollinators for many years, has recently helped to launch Bumble Bee Watch, a citizen scientist survey and monitoring project and website. As soon as I learned of this site, I searched through my old photos for some that I could submit. I didn’t find many. Bumble bees are difficult to photograph—they rarely stay still and if they do, their head is buried out of sight in the petals of the flower they are visiting. Out of three years of photos, I was more than a little disappointed to find only four bees to submit. Even still, it was satisfying to make even this small contribution to this wonderful new project.

Brown-belted Bumble Bee, Northfield, Minnesota, July 30, 2013
Brown-belted Bumble Bee (Bombus griseocollis) – Northfield, Minnesota, July 30, 2013

Last spring, aided by a copy of Befriending Bumble Bees: A Practical Guide to Raising Local Bumble Bees by Elaine Hodges, Ian Burns, and Marla Spivak, I attempted to rear bumble bees. I built the small boxes for the queens, in some ways like match-box size rabbit hutches. Rolled pollen balls. Prepared nectar. Captured and detained four separate queens: one Common Eastern Bumble Bee (Bombus impatiens) and three Two-spotted Bumble Bees (Bombus bimaculatus). None of them nested. I think my mistake was that I didn’t keep the queens in the starter nests warm enough (last spring was not an average spring, resembling rather a two-month extension of winter). When the queens didn’t show signs of nesting, I set them free. Hopefully this year I’ll have better luck coaxing a couple queens into starting a nest. Beyond the satisfaction and entertainment of rearing a colony, it seems useful to pursue the possibility of providing some local farmers with local pollinators.

Earlier this week, yet another bumble bee book landed in my mailbox: the new identification guide Bumble Bees of North America by Paul Williams, Robbin Thorp, Leif Richardson, and Sheila Colla. And while I’ve only just begun to read through the front matter, and flip through the individual species accounts, this surely will be another great asset to anyone working with bumble bees in North America.

So, if you’re still wondering what you can do for bumble bees, I’d recommend digging into any of the books mentioned here during the few weeks left of winter. Then do some gardening, add some native plants that will provide native bees with needed nectar and pollen to your property. If you want to do more, throw some support to The Xerces Society or other organizations conserving needed habitat and start telling others about ways to support native pollinators.

Bumble Bees of North America
Bumble Bees of North America

First Wasp of 2014

Northfield, Minnesota. March 17, 2014
Northfield, Minnesota. March 17, 2014

Our always vigilant cat noticed this tiny wasp (6mm in length) on a rug in our kitchen. I believe it belongs somewhere among the Aphid Wasps (Pemphredoninae). The wing venation, the single submarginal cell, is a little curious and doesn’t match any of the illustrations in Bohart and Menke (1976), so I haven’t been able to proceed much farther than the subfamily.

Finding an aphid-hunting wasp in the house in March in Minnesota raises some questions, especially with the snow still piled deeply outside. Being a cavity nester, it could have emerged from some of the stems and galls I have sitting out in my office. That’s one possibility. But, given the porosity of the walls and foundations of this old house, the avenues for a creature this size to enter into our living space are many and, having not seen a living wasp of any kind for quite a number of months, most welcome.

Northfield, Minnesota. March 17, 2014.
Northfield, Minnesota. March 17, 2014.

Trap Nest: Part Three

Trap Nest: Part Three

An examination of the open trap nest revealed four occupied cells and one empty cell, a vestibular space between the nest plug and the occupied cells. Three of the occupied cells contained potter wasp larvae, the fourth, the one closest to the entrance, did not. It held, apparently, the remains of the original provisioning, as if the potter wasp egg never hatched. Placing the nest and this suspect cell under the microscope, I discovered two tiny wasps (both dead), three tiny cocoons (one still full), and a bunch of mummified caterpillars. Something had obviously gone wrong in this cell.

Trap nest cell contents
Trap nest cell contents

The cell in question, being the closest to the entrance, was the last to be provisioned. It appears, bad luck for the provisioning wasp, that one of the caterpillars captured and placed in the cell must have been secreting a number of parasitoid wasp larvae. Like the clever Greeks in the Illiad, these wasp larvae emerged from their caterpillar host (the substitute for the Trojan Horse in this metaphor) at some point after being sealed into the cell. Unlike the successful Greeks, these stowaways perished. Not having the mandibles or the mud-dissolving spit required to breach the mud partitions, they died, immured in the dark. In describing this, I feel other literary echoes, namely the horror story The Cask of Amontillado by Edgar Allan Poe. Of course the fate of the caterpillars in this cell is hardly more disturbing than the fate of the other caterpillars stung into paralysis, then devoured alive.

These wasps really were small, just a couple millimeters in length, no larger than an Argentine Ant, that common pillager of kitchen sugar. The wing venation indicated the wasps were of the family Braconidae, a large family of parasitoids with more than 1,700 species in North America. Interestingly enough, some braconids have been used as biological agents in the control of agricultural pests, pests such as the Cabbage Butterfly. Many species are colored black and red or black and orange. Since βρακον is Greek for breeches (or pants in a less stilted dictionary) I wonder if the brightly colored hind legs resulted in the family name or if it’s those swollen thighs, the coxa, that gives the family its name? As far as I could determine, these particular wasps belong to the family Agathidinae, though in consulting a recent key to the Agathindinae I couldn’t make it past the first binomial because my microscope isn’t powerful enough to examine the shape of the foreclaws, so I don’t even have a guess at the species.

Braconid wasp
Braconid wasp

While the Braconidae are interesting in their own right, this failed cell also provided an opportunity to look over the provisions. Seven small green caterpillars, all probably of the same species (no prolegs on A3, patterned prothoracic shield) were preserved. According to both Cooper and Krombein, Ancistrocerus antilope (the likely provisioner of this nest), stuffs its nest full of small caterpillars, most often the tiny larvae of micro moths—the crambid moths, the twirler moths, the concealer moths—and that appears to be the case here. My best guess, after an hour browsing bugguide, would be a Tortricid moth larvae (Tortricidae, tribe Archipini; possibly Choristoneura sp. which seemed to have a very similar prothoracic shield). The cell also contained a different species of caterpillar, 2 to 3 times as large as the others (prolegs on A3-A6, no prothoracic shield). It seems likely that this caterpillar hosted the wasps.

Krombein also reported that Ancistrocerus antilope provisioned its cells, on average, with 3 to 10 larvae, usually of a single species, and usually of early instars, the selection of early instars no doubt lowering the likelihood of interring a larvae containing parasitoids. And Krombein, out of thousands of trap nests examined, reported braconids in just two! I feel fortunate to have happened upon this complication so early in my trap nesting career.

The nest, reassembled, has been overwintering on a frosty window sill in my cold, corner office, sitting alongside plastic cups with dragonfly nymphs, other containers filled with Lepidoptera cocoons, and several heaps of gathered plant galls. It’s a nice place to sit on a cold winter day, one large creature among numerous little creatures, all of us biding our time, preparing for warmer weather.

If I hadn’t set out this trap, I wouldn’t have learned of these wasps, or known about their presence in our back yard. I wonder, often, about how few people know or care about these small happenings. I worry, just as often, about my own lack of understanding, the little I really know about the complexities of even my backyard, let alone the larger world. And I suspect, more and more, that it’s simply a failing of patience and of imagination if, for instance, a certain moth caterpillar runs rampant in our gardens and we reach for insecticides, not trusting the unseen checks to their population provided by wasps and other predators.

I think the tension, here, is between what we manage and what we don’t manage. What escapes our hand widens and grows wild. This is not pristine wild, but salvaged wild, the wild that creeps back over the land, resettling the unweeded margins, homesteading the fallow flower pots, mining the messy understory and the fetid margins of the compost. When I see weeds I see hope; and when I see unmown, unsprayed lawns I see progress being made.


Cooper, K.W. 1953. Biology of eumenine wasps. I. the ecology, predation and competition of Ancistrocerus antilope (Panzer). Trans. Am. Ent. Soc.79: 13-35.

Evans, H. E. 1963. Wasp Farm. New York: Natural History Press, Doubleday.

Krombein, K.V. 1967. Trap-nesting wasps and bees: life histories, nests, and associates. Smithsonian Press, Washington D.C. vi + 570 pp.

Trap Nest: Part Two

Ancistrocerus antilope on Narrow-leaved Goldenrod
Ancistrocerus antilope on Narrow-leaved Goldenrod

The object left deliberately undefined in the previous post is a trap nest, a small stick of wood with a pre-drilled hole designed for collecting wasps, especially potter wasps, hence the mudded up circle in the center. This particular nest was retrieved in November from the gaps in the cement blocks beneath our rain barrel. Last June, happening across several empty nests in the garage, I set the traps: two under cross braces on the garden fence, another beneath the rain barrel. Throughout the summer, whenever it occurred to look at them, they remained unused. That was ok…for I was preoccupied with other entomological endeavors, such as rearing bumblebees (not a success), journeying to Saskatchewan, or surveying local dragonfly populations. Mostly, while in the field on dragonfly business or busy in the backyard, I kept at my incidental collecting of adult wasps from flowerheads throughout the summer, a sideline occupation. Nevertheless, this non-methodical approach yielded a surprising variety of wasps.

In August, I ordered several redwood Schmitt boxes from the Bohart Entomology Museum at the University of California, Davis. These vintage insect boxes would be perfect for housing my small collection until it can be transferred to a curated collection at one of the local colleges. Before placing this order I browsed the used and antiquarian books the museum was offering for sale as a fundraiser. One caught my eye: Trap Nesting Wasps and Bees: Life Histories, Nests, and Associates by Karl V. Krombein (Smithsonian Press,1967).


In this book, Krombein (1912 – 2005) documents the contents of over 3,400 trap nests. It is certainly a classic of the study of Hymenoptera and I was lucky to find a copy. The arrival of this book and the storage boxes in the mail instantly rekindled my interest in trap nests. I set about preparing a number of new nests but almost simultaneously the weather turned cold and the season was over. So I’d have to wait until next summer. Read and wait.

I revisited the pages in Wasp Farm where Howard Ensign Evans discusses trap nesting. When I read this account some years ago, I followed the simple instructions and prepared a handful nests for my own use. These went unused for several years. I remember a couple of them sitting upright on a bookshelf, functioning as rustic vases, holding sprigs of bittersweet and a dried thistle flower. Then, during the summer of 2012, I finally got around to setting them out in a variety of places in the back yard, successfully collecting wasps from two of the nests.

While I have the specimens from the two nests, I didn’t gather all the data I might have. One nest was presplit, but when I opened it the larvae tumbled out and the information regarding their order in the nest was lost. These larvae were placed in vials where they pupated and, some weeks later, emerged as adults. Nor did I take note of the structure of the nest. And while the second nest was left intact for later examination, the examination never happened because the wasps emerged while in storage. The wasps in both nests, after graduating from translucent white larvae to opaque winged adults, were identified as Ancistrocerus antilope, a common, black-and-yellow potter wasp. There was, however, a single, bright metallic-blue exception…a cuckoo wasp (Chrysididae). This resplendent intruder, a kleptoparasite of cavity nesting wasps, had grown from a stealthily deposited egg, usurping one of the potter wasp’s cells and its provisions. The presence of both of these species in our backyard was surprising, for I’d never noticed either of them before.

Now, a little over a year later, I found my third occupied trap nest. It had been weeks since I’d seen a dragonfly and wasps were nearly the last thing on my mind when I happened upon the forgotten trap nest left in the blocks beneath the rain barrel. Finding it there and finding it occupied was a real treat, perhaps the year’s final entomological bonne trouvaille. Facing the cold winter months, the nest seemed a promise of the summer to follow.

Determined to document the contents of this nest properly (or at least better than the previous two), I consulted the methods section of Krombien’s book. When he retrieved nests from the field, he opened them, recorded the contents and structure of the nests, then closed them up again for overwintering and rearing. The wasps need to be reared to adults in order to be identified to species. Simple enough, right?

Well, the block of wood used for this particular trap nest contained a knot and splitting it turned out to be rather nerve-wracking, involving the violent touch of hammer and chisel. But eventually the grain grave up its grip and split, right along the bore-hole as planned, leaving the contents visible and intact. I took a quick photograph alongside a ruler for the records. Looking at the cells…the first cell had no larva, and appeared to be still filled with provisions. Perhaps the egg didn’t hatch or the larva had died. A closer look at the contents revealed a rather interesting drama within the already interesting drama of the nest itself. Details forthcoming in the next post…

Opened trap nest. The suspect first cell is to the left of the two larvae (below the ruler at the 3 to 5cm mark).
Opened trap nest. The suspect first cell is to the left of the two larvae (below the ruler at the 3 to 5cm mark).


Evans, H. E. 1963. Wasp Farm. New York: Natural History Press, Doubleday.

Krombein, K.V. 1967. Trap-nesting wasps and bees: life histories, nests, and associates. Smithsonian Press, Washington D.C. vi + 570 pp.