The Daily Entomologist

Ento-musings from the University of Kentucky Department of Entomology

Monday, May 30, 2016

News of a Trigonalid

Back on April 30th, I found an adjoining pair of potter wasp nests (likely belonging to Eumenes sp.) while on a collecting trip to Zaleski State Forest with the Ohio State University's undergraduate entomology club. At the recommendation of one of my fellow students, I saved the stout clay pots in hopes that something more interesting than the offspring of their creator would emerge.

My hope paid off just one day shy of a month later, when two distinctly non-eumenine wasps emerged, one from each pot: both larvae had been parasitized (females of the Eumenini lay a single egg in each jar; Hermes et al., 2015). Much to my pleasure, the parasitoids I had unwittingly collected were Lycogaster pullata, a member of the small, seldom-encountered family Trigonalidae.

Four genera of trigonalids are present in North America. They tend to be moderately sized, chunky wasps with unreduced wing venation and >16 flagellomeres, distinguished from other apocritans of this description by finger-like ventral projections at their tarsomeres' apices and reduced ovipositors in females (Goulet & Huber, 1993). Distinctive enough to warrant their own superfamily, trigonalids have most recently been classified within the infraorder Evaniomorpha (Heraty et al., 2011).

The reduced ovipositor is a consequence of the wasps' distinctive biology, the convolutions of which are at least partially responsible for their rarity: rather than lay eggs directly upon or within their desired hosts, trigonalid females oviposit large quantities of minute eggs in foliage, where they are ingested by herbivorous sawfly and lepidopteran larvae. This strategy is not unique, but trigonalids add a bizarre wrinkle in that they are for the most part obligate hyperparasitoids, attacking ichneumonid or tachinid larvae that are themselves parasitoids of the insect that originally ingested the eggs (Murphy et al., 2009).

L. pullata has been reported both as a hyperparasitoid, and as facultatively employing a different stratagem—the one employed by the particular specimen I collected (Smith, 1996). Namely, it (and other trigonalids) may parasitize the larvae of vespid wasps (including eumenines) that provision their nests with caterpillars, infesting these hosts through inadvertent larval ingestion of minute trigonalid larvae. Evidently, one should thoroughly chew one's food.


Goulet, H and Huber, J. T. (1993). Hymenoptera of the World: an Identification Guide to Families. Ottawa: Agriculture Canada.

Heraty, J.; Ronquist, F.; Carpenter, J. M.; Hawks, D.; Schulmeister, S.; Dowling, A. P.; Murray, D.; Munro, J.; Wheeler, W. C.; Schiff, N.; and Sharkey, M. (2011). Evolution of the hymenopteran megaradiation. Molecular Phylogenetics & Evolution, 60, 73-88. 

Hermes, M. G.; Araujo, G. and Antonini, Y. (2015). On the nesting biology of eumenine wasps yet again: Minixi brasilianum (de Saussure) is a builder and a renter… at the same time! (Hymenoptera, Vespidae, Eumeninae). Revista Brasileira de Entomologia, 59(2), 121-142. Retrieved 5/30/16 from

Murphy, S. M.; Lill, J. T.; and Smith, D. R. (2009). A scattershot approach to host location: uncovering the unique life history of the trigonalid hyperparasitoid Orthogonalys pulchella (Cresson). American Entomologist, 55, 82-87. Retrieved 5/29/16 from

Smith, D. R. (1996). Trigonalyidae (Hymenoptera) in the eastern United States: seasonal flight activity, distributions, hosts. Proceedings of the Entomological Society of Washington, 98(1), 109-118.

Tuesday, May 19, 2015

Switch On Those Mercury Vapor Lights: It's Time for Pyrgotids

Recently, I at last collected an example of an insect taxon I have long coveted: the Pyrgotidae, a family of acalyptrate flies that (so far as is known) are parasitoids of scarabaeid beetles (Marshall, 2012). The species in question is Pyrgota undata: a large, colorfully patterned insect that bears more than a passing resemblance to a polistine wasp in flight, yet could not be mistaken for anything other than itself when perched.

Female P. undata are known for intercepting airborne "June beetles" (Phyllophaga sp.) and ramming a lone egg between the hapless beetle's momentarily exposed tergites; since these coleopterans are their sole hosts, they can only be found during these beetles' flight periodin Kentucky, mid-April through late May—and during that period when the beetles are most active, namely, at night (although P. undata may rarely be visible during the sunlit hours, as happened in the case of the specimen I personally collected) (Swan & Papp, 1972). 

There are merely five genera of pyrgotids in North America (Steyskal, 1978); the family as a whole is distinctive in their lack of ocelli and noticeably protuberant frons (Borror & White, 1970). Of the Nearctic species, P. undata is by far the most likely to be encountered by the layperson.


Borror, D. J. and White, R. E. (1970). A Field Guide to Insects: America North of Mexico. Boston: Houghton Mifflin Company. 

Marshall, S. (2012). Flies: the Natural History and Diversity of Diptera. Richmond Hill: Firefly Books Ltd.

Steyskal, G. C. (1978). Synopsis of the North American Pyrgotidae. Proceedings of the Entomological Society of Washington, 80(2), 149-155. Retrieved 5/19/15 from 

Swan, L. A. and Papp, C. S. (1972). The Common Insects of North America. New York: Harper & Row Publishers.     

Tuesday, December 30, 2014

An Overview of Archostematan Beetles

Some years ago, I had the privilege of attending an entomology/forestry camp provided by the University of Kentucky near Jabez, KY. Aside from learning the "racist" system for distinguishing white vs. red oaks and collecting my first mantidfly (Dicromantispa sayi), I also happened upon a specimen of the beetle Tenomerga cinerea, a member of the Cupedidae. In North America, these are the most commonly encountered examples of the suborder Archostemata: which, despite being less diverse than most other beetle suborders, display enough variety to justify an overview

Wednesday, August 6, 2014

Armadillo Ants and Odd Moths

Now that I have reached something of a respite from the terrors of my summer class, I can take the time to post links to the two most recent offerings on my personal blog (Life, et al.). The first summarizes our knowledge of a tiny subfamily of rare ants (the Agroecomyrmecinae) which have received the epithet of "armadillo", owing to a most distinctive habitus: as with most rare ants, this knowledge is frustratingly scant.

The second was inspired by my collecting a nondescript grayish moth on the Ohio State University's main campus; it was trapped within the set of double doors leading into my favored cafeteria, which create an aerial suction that ensnares insectile flyers-by. I subsequently identified this moth as Fulgoraecia exigua, the caterpillars of which are noted for their peculiar custom of feeding on planthopper innards. As a result, I set out to post some information not just on F. exigua but concerning their strange family (the Epipyropidae) as a whole.  

Saturday, March 15, 2014

It's About Time March Became Earwig Appreciation Month

St. Helena, an island in the South Atlantic located roughly over 1,200 miles distant from the nearest major landmass (Africa) and 810 from the nearest fellow isle (Ascension) is better known than most places of comparable remoteness: mainly since it served as the place of Napoleon Bonaparte's final exile and eventual death.

As far as I am concerned, the island's principal claim to fame would be the sole home of the world's largest earwig (84 millimeters long including forceps): Labidura herculeana, has not been seen since 1967 and is thus very likely extinct, probably due to the introduction of invasive predators. (Of course.) Construction of the St. Helena International Airport (which commenced in 2012) is no doubt swiftly extirpating whatever population may remain.

This sad event only draws attention to the lack of respect that earwigs (order Dermaptera) commonly receive from Earth's only sentient species. Although it is too late to save the St. Helena giant earwig, I have volunteered to remedy this dearth of appreciation for dermapterans by creating a blog post on their murky evolutionary history (in lieu of petitioning that March be designated Earwig Appreciation Month).

Beware the Ides of March...   

Friday, December 27, 2013

Slavery: Does it Exist in Ants?

On the afternoon of (the most recent) August 13, I observed a spectacular (in myrmecological terms) raid by Formica sanguinea-group ants upon their cousins (Formica fusca-group). The trail of pupa-laden aggressors could be traced some 20 meters from the assaulted colony (which I, a human who tries to pay close attention to what is going on in his own front yard, was unaware of prior to this event) before I lost track of it in some non-mowed grass.

The purpose of the abduction of brood was not simple predation: once they eclose, the Formica fusca will assimilate into their abductor's society, caring for the brood of F. sanguinea without a fuss. They are treated as full members of the colony into which they were inducted: a behavior termed dulosis. Humans (English-speakers at least) have colloquially called it "slave-making" for 203 years; this popularity belies fundamental dissimilarities between human slavery and dulosis, which I iterated in a message-board rebuttal some five years ago:   

"Furthermore, referring to some kinds of ants (such as Harpagoxenus and Polyergus) as “slave makers” is another sad example of ants being anthropomorphized by uninformed laymen. Calling them 'adopters' or 'foster families' would be more accurate. While it is true that ants that practice dulosis (a behavior in ants that humans often inaccurately term as 'slavery') brutally kill other ants to capture those ant’s pupae, those ants that emerge from the said pupae are brought up as members of their foster colony and are never discriminated from their 'enslavers,' as far as myrmecologists can tell. I define slavery as being the capture of a member of your own species and the coercion of that individual to do work that you consider too dirty, dangerous, or dull (DDD, if I may utilize an acronym originally used in robotics) for you to do yourself: on the other hand, while the notorious dulotic myrmicine ant Strongylognathus emeryi, for instance, makes those ants that it has “enslaved” do work that it never does (namely, feeding other S. emeryi members of the colony), this is not because it is unwilling to do this work itself but because it is unable to, because the gigantic mandibles it possesses are (get this!) too massive and clumsy to do anything but slice apart other ants. Dulotic ants never enslave their equals [those of the same species]—the closest human analogy to dulosis would be a human family stealing a baby monkey from its parents, bringing it up as one of their own, and training it to answer the telephone because the humans did not have an answering machine and were usually too busy to answer it themselves." [July 9, 2009]

...I need not even mention the racial baggage that is hauled into the harsh light whenever the word slavery is mentioned, not only in the United States but elsewhere around the globe. Thus, it would behoove us to phase out the term in myrmecological situations: not motivated by some fearfully reflexive desire for political correctness, but because science is a search for truth; and to call the behavior I saw for myself back in August "slavery" is nothing but an untruth. But what should the vernacular substitute be? 

First let us ask: why bother with such a substitute? Couldn't we simply use "dulosis"—a term specifically coined for the syndrome it denotes, and not a verbal hand-me-down from some unrelated activity—and call it well and good? I would be the first to say yes, but many would disagree. You see, dulosis is an attention-grabbing behavior: one violent enough to hold the interest of the general public, at least during those brief intervals when TMZ and its ilk are inactive. The sciences require the investment of the masses in order to thrive: and anything scientific that can compete with twerking pop stars is in need of a good vernacular name. (Assuming that the body politic consists mostly of infantile yahoos, which may not be so axiomatic as is thought.)

Professor Joan Herbers put it this way in an article pointing out the inappropriateness and repellent connotations of the "slave-making" simile (underlining mine): 

Yet discarding metaphors altogether in favor of obscure jargon is incompatible with interesting students and the public in my work. While no metaphor can be perfect, I offer an alternative. I suggest that we replace “slave-making ants” with “pirate ants.” Pirates certainly take captives when they board ships, and pirates rely on forced labor. We can replace “slave” with “captive” and “dulosis” with “leistic behavior,” from the Greek for pirated spoils, leistos. To be sure, the pirate metaphor has its own imperfections when we use it to describe ant behavior—but the social impact on audiences, if anything, might be positive. I, for one, prefer audiences to identify my work with Captain Jack Sparrow than with Simon Legree.
I submit that we scientists have a responsibility to communicate effectively. To do so, we must listen to those who study the impact of words. If the terminology we use is degrading or offensive, then it is time to change the terminology. (Herbers, 2007)

One wonders if Professor Herbers considered that she might have hereby offended the countless hostages who have been held by the pirates active off the Horn of Africa in recent years; or that making a plea to something as fickle as pop culture to lend weight to a scientific concept is distinctly unconvincing. (Honestly, who will remember that "Pirates of the Caribbean" even existed in a few more years?) In any event, piracy just as much as slavery is a conspecific activity driven by trade: essentially different from dulosis.

Sainted macrophotographer/myrmecologist Alex Wild proposed "kidnapper ants" (Wild, 2013) for his part: if dulosis could be called "forcible adoption", then perhaps kidnapping is the best human analogy we have. There are downsides to the phrase: yet again, by doing so we liken dulosis to a human activity often motivated by profit—and this desire for monetary aggrandizement is unique to Homo sapiens. Moreover, kidnapping is not usually motivated by a need for labor.

Bernard Werber, in Le Jour des Fourmis (1991), drew a comparison between ant "slaves" and the yeniçeri ("new militia") of the Ottoman Empire, anglicized as "janissaries" (p. 236) (this analogy was also noted by Benoit Guenard in Myrmecos' comments section): these warriors were abducted as children (a practice called devşirme) and indoctrinated to form the Sultan's personal bodyguard; drawn from Christian communities of the realm, they would fight loyally against their own kin (Werber, 1996). Shall we then call slave-makers "devshirme-ants"? Possibly, but even here we risk giving offense to the Armenians and Greeks from whom the janissaries were drawn by the Turks, and who still remember their old oppression. 

In the end, I must say that "kidnapper ant" will suffice; although for my part, dulosis (or the synonymous cleptergy) is a superior sobriquet. Why did I wait until December to write all this? A lack of time to complete the counterpart post on my personal blog, which situates dulosis in its broader ethological context: for ant-kidnapping is but one aspect of the phenomenon known as social parasitism. (Be sure to read Part 1 first.)    


Herbers, J. M. (2007). Watch your language! Racially loaded metaphors in scientific research [electronic version]. Bioscience, 57(2), 104-105. Retrieved 12/27/13 from

Werber, B. (1996). Empire of the Ants. New York City: Bantam Books. 

Wild, A. (October 24, 2013). Polyergus moves forward, and a modest proposal for kidnapper ants. Retrieved 12/24/13 from            

Tuesday, October 8, 2013

Flies of the Small-Headed Sort

The only flies more adorable than the big-headed ones (Pipunculidae) are their unrelated counterpoints, the flies of the Acroceridae. I was thrilled to find one (Acrocera orbiculata) on June 1 in Berea, KY, near the eponymous College's community garden. Inspired by this discovery, I've written a full-blown blog post on the Acroceridae (and their kin, the Nemestrinidae). These absurdly proportioned insects are seldom collected, and are especially rare in the United States east of the Mississippi. And yes: they are parasitoids. Heck, I should just call my personal blog Parasitoids, et al. and be done with it...