Researching Pelecinids – Part 2

One of the most useful resources the Triplehorn Insect Collection has to offer is its extensive HOL database, an online taxonomic initiative that documents collected specimens of various insect groups. This database already contains records for over 845 thousand Hymenoptera specimens, and it continues to grow every week through the hard work of countless contributors.

One way to contribute to HOL is to photograph and upload images of collected specimens, further enriching the available data on specific taxa. Prior to the start of my research on pelecinids, there were zero images of the genus Pelecinus available in the database. To remedy this, I had the opportunity to work with Jordan Reynolds, an undergraduate student in Art & Technology who is currently working on specimen photography for the collection. Over the last several weeks, Jordan taught me about the technologies and techniques required for taking high-quality images for the database.

My goal in photographing a selection of the collection’s Pelecinus polyturator specimens is three-fold. First, I will obtain a more in-depth understanding of the external anatomy of these intriguing insects. Second, I can compare the morphologies of males and females of different sizes and localities. Third, I will contribute previously unavailable data to the HOL database.

Photographing collection specimens is not as simple as taking a picture with a camera. Because the specimens are relatively small, and because we require intricate detail in the images, we instead use a method known as focus stacking. With this method, the camera gradually moves along a track and takes multiple images at different distances. The focused areas of each image are then “stacked” together by a computer program so that the entirety of the final image is clear. Because the P. polyturator specimens required a large depth of field, we sometimes had to photograph and stack up to 100 images to create a sufficiently focused final image.

In addition to taking individual specimen images, we also took several comparison images. These provide a quick side-by-side comparison between two different specimens. Some of the images we took compare males and females of similar localities. Other images showcase females of similar localities and their dramatic variance in size.

comparison image of P. polyturator females

Comparison image illustrating the size variation in P. polyturator females

Of course, no system is perfect, and we faced many challenges along the way. Most of the parasitic wasps that get photographed by the collection are very small in size (no more than a few millimeters long). Therefore, the collection’s microscopic camera that is traditionally used for parasitoid photography is designed to take highly detailed images of very small specimens. P. polyturator females are unusual in that they are very large parasitoids that can exceed 40 mm in length. Because of this, many of the specimens we wanted to photograph could not fit under the microscopic camera. We instead opted to use a DSLR camera, which is used for macrophotography of larger specimens such as beetles and butterflies. Using this nontraditional method of parasitoid photography, we were able to produce high-quality images of the larger specimens by exploiting various imaging techniques.

Another challenge we faced was the handling of the specimens. All mounted insects in a collection must be handled with great care because they are dry and brittle. Pelecinids must be handled with extra caution because their long, string-like antennae and fragile abdomens will break with even the slightest bump.

We ended up with many beautiful images of these wasp specimens. The complete collection of images has been uploaded to HOL and is available on the page dedicated to P. polyturator. I would like to thank Jordan for all of his help with this photography endeavor. Without the countless hours he spent performing behind-the-scenes image processing, the final images could never have turned out so well.

About the Author: Hannah McKenzie is an undergraduate entomology major at the Ohio State University. She currently works at the Triplehorn Insect Collection and is participating in undergraduate research on Pelecinus wasps.

Researching Pelecinids – Part 1

image of a pelecinus wasp

Wasp in the genus Pelecinus, image by Cynthia L. McLaughlin and licensed under CC BY 2.0

Many years ago, arthropods were one of my greatest childhood fears. I was so petrified of bugs that I hardly ever went outside during the summer. Anyone who knew me as a child would never have guessed that I would someday develop a passion for entomology and a love for the insect world. I began to collect insects in little plastic jars, but my rudimentary “collection” might as well have been a dermestid buffet; this was long before I understood how to properly store, curate, and preserve specimens.

It wasn’t until my final year of high school that I realized that I could become an “entomologist” as a profession, a life-changing revelation. During the summer of 2016, I finally learned how to make a proper insect collection at the Ohio State University’s Stone Lab, where I enrolled in a week-long course on insect field biology. That autumn I started my first semester at Ohio State as an entomology major, commuting every day from my home in Westerville, Ohio.

I recently completed my first year in the entomology undergraduate program, and I couldn’t be more excited about my academic future. I have met so many great peers and faculty members within the entomology department, and I have had the chance to explore entomology in ways that my younger self could never have imagined. I joined my general entomology class on an all-day collecting trip in Hocking Hills. I visited the on-campus insectary and learned about rearing insects with Chrysalis Entomology Club. But perhaps the most enlightening experience I have had so far was my interaction with the Triplehorn Insect Collection. I participated in an internship at the collection during autumn semester, then continued to work there part-time during spring semester. This summer I plan to continue working at the collection, but now the collection has presented me with yet another exciting opportunity: working on my first undergraduate research project.

image of a June bug

Unidentified June bug (Phyllophaga) from central Ohio, image by author

I will work with Dr. Norman Johnson and Dr. Luciana Musetti over the summer to research wasps belonging to the genus Pelecinus. These beautiful insects may appear intimidating with their long, slender abdomens, but they are not aggressive toward humans and stings inflicted by their small ovipositors are rare. Their flexible abdomens are instead used to parasitize the larvae of Phyllophaga beetles, more commonly known as “June bugs”. The female wasp does this by thrusting its abdomen into the ground and ovipositing into the subterranean grubs.

My research will focus on Pelecinus polyturator, a species that can be found in areas of South America and in North America east of the Rocky Mountains, including here in central Ohio. One of the most interesting aspects of P. polyturator is that males are extremely uncommon north of Mexico but become much more common further south.

The goal of my research is to examine P. polyturator specimens from both northern localities and southern localities and determine if they are one species or if they are actually multiple distinct species. This can be determined using nondestructive DNA extraction and barcoding, which consists of using a species-specific genetic marker in a specimen’s DNA for species identification. I do not have any prior experience with DNA barcoding, or even molecular genetics in general, so I see this as an incredible opportunity to learn new skills that will benefit me throughout my entire scientific career. I will also get to learn first-hand how specimens such as Pelecinus wasps end up in an insect collection by going through the complete collecting process, from malaise trapping all the way to entering specimen data in the collection’s online Hymenoptera database.

At the conclusion of this research project, I plan to present my findings at both the Denman and the CFAES Undergraduate Research Forums. One of my main hopes for this project is that it can be used to illustrate the research experience for other students interested in undergraduate research, both entomological and otherwise.

As I continue to learn more about topics such as DNA barcoding, specimen collection, and Pelecinus wasps themselves, I will update this blog so that everyone reading can learn alongside me and watch the progress of my research in real-time. Keep watch for another post from me next week about taking photographs of P. polyturator specimens currently owned by the collection. I can hardly wait to share these images and the photography process behind them.

About the Author: Hannah McKenzie is an undergraduate entomology major at the Ohio State University. She currently works at the Triplehorn Insect Collection and is participating in undergraduate research on Pelecinus wasps.

Chalcidoidea: Minute “Gems of the Woodlands”

Lelaps sp., parasitoid wasp (Hymenoptera: Chalcidoidea: Pteromalidae) from the Amazon Basin, specimen ID = OSUC 45851; image by the author.

Lelaps sp., parasitoid wasp (Hymenoptera: Chalcidoidea: Pteromalidae) from the Amazon Basin, specimen ID = OSUC 45851; image by the author. (original title: Unidentified chalcidoid wasp (Pteromalidae) from the Amazon Basin)

I have always been fascinated by insects, but it was not until, at age 15, I took a week-long field insect taxonomy course at the Ohio State University’s Stone Laboratory. There, I learned the conventions of arthropod collection and preservation and something of proper curatorial practices. Ever since, I have steadily accumulated a collection with pretensions made modest by the limited resources of a teenager; and collection and identification remain an exceedingly enjoyable activity for me.

Therefore, it was only natural that I gravitated to the Triplehorn Insect Collection upon commencing my undergraduate career. Sorting unidentified specimens was easily my favorite task there. Although the collection contains the full range of insect diversity, those specimens that I was tasked with identifying almost always belonged to the order Hymenoptera—often casually referred to as “ants, bees, and wasps”, but technically including far more taxa than simply those that happen to have colloquial names.

Being one of the four most diverse insect orders, the variety of Hymenoptera is considerable: and I encountered much of their phylogenetic span through this process, while becoming intimately familiar with Goulet and Huber’s tome Hymenoptera of the World: an Identification Guide to Families (1993) (PDF), the monochromatic line drawings within which—printed on thick, coarse paper—have caused hymenopterists to nickname it “the coloring book”.

As an exemplar of the many taxa with which I thereby became familiar, I have chosen to briefly discuss the superfamily Chalcidoidea herein. These parasitoid wasps (using what is a phylogenetically useless term) are one of those aforementioned many prominent insect taxa that have no name in the vernacular—understandable, given that the vast majority of these particular parasitoids are a few millimeters in length or less. (Indeed, the smallest insect known to science—the 0.13-mm.-long male of Dicopomorpha echmepterygis [Mockford, 1997]—is a chalcidoid.)

This diminution has also resulted in a lack of taxonomic attention from entomologists, and chalcidoid systematics is by consequence a frustratingly opaque matter—something one is immediately impressed with while attempting to identify the miniscule things: keys are peppered with qualifiers like “usually” and “most”, not to mention annotated with lengthy footnotes elucidating the exceptions to each couplet. The fundamental problem at hand, as Goulet and Huber point out, is that chalcidoid families are often defined by combinations of characters, as opposed to singular traits that are unique to that taxa and none other (synapomorphies, in cladistic terms). This has resulted in a superfamily littered with taxa whose boundaries are under constant debate (e.g., the Agaonidae) or that do not hold up to scrutiny whatsoever (the grossest wastebasket taxon of flagrant wastebasket taxa, the Pteromalidae).

Chalcidoids are hardly deserving of this neglect, considering their ecological and numerical diversity (they possibly constitute 10% of all insect species; Noyes, 2003). I would have impartially respected this significance regardless of my work at the Collection, but parsing through unit tray after unit tray of nigh-microscopic specimens representing untold numbers of species—each one a chalcidoid—gave me a concrete grasp of that abstraction.

I still have strong visual impressions of many of them: the subtly turquoise, spatula-shaped abdomen I swiftly came to associate with the Tetracampidae; the minute serrations on the inner rims of a stocky chalcidid’s femora, making its thighs appear like chitinous razors; the oar-like forewings of many an insubstantial mymarid, fringed with haloes of setae; the metallic, spindle-shaped abdomen that accounted for two-thirds the length of a sycoryctine. I am not the only one to have thought them often quite showy under sufficient magnification: Alexandre A. Girault, a notoriously verbose chalcidologist, spoke of the tiny wasps as “gem-like inhabitants of the woodlands, by most never seen or dreamt of” (Thomer & Twidale, 2014).

Suffice it to say, without my work at the Collection, I would not have seen nor dreamt of so many chalcidoids.

Mockford, E. L. (1997). A new species of Dicopomorpha (Hymenoptera: Mymaridae) with diminutive, apterous males. Annals of the Entomological Society of America, 90, 115-120.

Noyes, J. S. (2003). Universal Chalcidoidea Database. Retrieved 5/18/16 from

Thomer, A. K. and Twidale, M. B. (2014). How Databases Learn. In: iConference 2014 Proceedings (pp. 827-833). Retrieved 4/8/15 from


About the Author: Zach Griebenow is an undergraduate majoring in entomology at the Ohio State University. You can read his personal blog on entomological matters here.

Fossils – a look into the past


Parasitic wasps in amber (above). These specimens have been studied and some are deposited at the Triplehorn Insect Collection.

No one really knows the number of insect species that have been formally described and named, but it is surely a six-figure number.  Of these, some will sure turn out to be duplications, but beyond that, the consensus opinion is that the real total number of different kinds of insects in the world is in the millions or tens of millions (and some think it may be even higher).  That leaves a lot of exploration, discovery and documentation left to do, the first two of those being the “fun” parts of insect taxonomy.

If those numbers are not not impressive enough, consider that the estimates only include insect species that are alive today! Most paleontologists (the scientists who study fossils) will tell you that the number of ‘extant species‘ (same as living species) is but a tiny fraction of all those that have ever existed on Earth.

Despite the fact that we taxonomists already have a monumental task in front of us with just today’s species, we also tend to investigate fossils as well. Why? Because they provide precious insight in the evolution of insects and help inform our research of the living groups.

Until recently the Triplehorn Insect Collection did not have any fossil specimens in its holdings. That’s partly due to our history — the collection is a reflection of the interests of previous curators, faculty and students associated with it, and their focus was in extant species.  It’s also partly due to the chronic lack of storage space that plagued our collection for so many years.  Another big obstacle is the fact that keeping fossils adds a whole new level of complication to our already complex curatorial task.

All that aside, my research interests, and those of my students and collaborators, led us to take a determined step into the past. As the current caretaker of the Triplehorn collection, that meant the addition of fossil insects to our roster. We started creeping into this new adventure slowly.  It began some 15 years ago with a colleague in Germany who is deeply interested in the insects embedded in amber, and in particular, Baltic amber.  He would sort specimens of parasitoid wasps of the group we are currently studying and offer to sell them to us.

Amber from the area around the Baltic Sea has been known since the Stone Age and was used both for jewelry and medicine.  Pieces were either collected along the shores or, later, actively mined in countries stretching from Denmark in the west to Russia in the east.  This is a huge area, and the deposits occurred over a long period of time.  The age, actually really the ages, of Baltic amber range from roughly 40 to 60 million years.  The amazing thing, for our purposes, is that insects, mites, and other small organisms would get caught in the sticky tree resin and be preserved for the ages.  In a good specimen it feels like you’re looking at something that was just collected yesterday, with all the smallest details of hairs and body texture perfectly preserved.  In fact, though, there’s usually very, very little of the original specimen left, and what we see is merely the cast of its body.

We began to slowly acquire amber specimens of the minute parasitoid wasps we study (order Hymenopera, family Platygastridae) and deposit them in the Triplehorn collection.  Slowly, not because these inclusions are particularly rare, but because they’re not cheap.  We now have several hundred of these, from which we’ve described a few new species and one new genus (Cobaloscelio Johnson & Masner in Masner et. al. 2007.)  On a global scale our collection is small and specialized.  Much, much larger collections with amber from many other places around the world may be found in, for example, the Museum of Comparative Zoology, the American Museum of Natural History, and the State Museum of Natural History in Stuttgart, Germany.

[Just as a historical side note, the main collection of Baltic amber used to be stored in the Zoological Museum in the city of Königsberg in Germany. This city is now known as Kaliningrad and is located in a small piece of Russia on the Baltic coast, otherwise surrounded by the country of Poland. Unfortunately, this museum and almost all of its contents were destroyed by bombardment during World War II.]

In the past few weeks we’ve graduated from our own small niche of amber wasps. This began when Ohio State’s Orton Geological Museum decided that they needed to make more space for dinosaur bones. Their solution was to find a new home for some of their fossil insect specimens. (Can you imagine prioritizing dinosaurs over insects? Neither can I.)  We decided that it was most appropriate for the material to stay at Ohio State, and so the Triplehorn collection is now the proud owner of hundreds of specimens of Green River Shale insects.

Moving the Green River Shale cabinets and drawers was strenuous work. Soon we’ll start the cataloguing process.

Fossils from the Green River formation are comparable in age to Baltic amber, but we know that number more precisely: 53.5 – 48.5 million years. And we’re no longer dealing with amber, but with rocks. There are three main deposits of Green River shale made up of the sediments that were deposited in mountain lakes near the present day area of the Uinta Mountains in Utah. They’ve been known to Europeans since the explorations of the West in the first half of the 19th Century, and the fossils are very well known. In fact, if you go to a natural history shop that sells fossils, it’s likely that some of the amazing fossils of fish you see come from the Green River deposits. The best areas for fossils were made from fine mud deposits. In those, the very small details of insects and spiders are preserved. Unlike amber though, these fossils are compression fossils, specimens that have been pretty much flattened by tons of sediments sitting on top of them.

Fossil Butte 2015.jpg

Fossil Butte National Monument in Wyoming. Not the kind of habitat where we’d normally be looking for insects!

The adoption of this collection will call for skills and expertise beyond those typical of a collection of dried insects. One thing we won’t have to worry about are “museum pests,” insects like carpet beetles that will feast on all sorts of dried organic matter such as the bodies of dead insects. Instead, we need to take into account the pure dead weight. These fossils are, after all, embedded in rocks. Handling hundreds of pounds of stones will surely put a premium on strong, athletic undergrad student assistants in the future!

Our tasks ahead are, first, using the records of the Orton Museum, to determine as precisely as we can the area(s) within the Green River Formation that these specimens were collected.  Then we’ll use our existing connections as well as the Fossil Insect Collaborative, to let paleoentomologists (entomologists specialized in the study of fossil insects) know that these materials exist and are available for study.  We need their help because, while we can distinguish beetles from flies, they are the ones who can figure out exactly which species of beetle or fly is in a particular fossil.

I have a colleague, recently retired, who always emphasizes that fossil collections add the critical dimension of “deep time” to our understanding of biodiversity.  With this new acquisition then, we hope to make a contribution to that understanding.  Along the way we’ll certainly learn a lot about paleontology and the curation of fossil insects.

Here’s a list of our work with Baltic, Canadian and Lebanese amber over the last several years. The Canadian and Lebanese materials are much older than Baltic amber, by about 80 million years! Some species and one genus were described based in part on specimens in the amber collection at the Triplehorn Insect Collection (photos, top):

Johnson, Norman F., Lubomir Masner, and Luciana Musetti. 2008. Review of genera of the tribe Sparasionini (Hymenoptera: Platygastroidea, Scelionidae), and description of two new genera from the New World. American Museum Novitates 2629: 1-24. (available online here)

Johnson, Norman F., Luciana Musetti, and Jens-Wilhelm Janzen. 2001. A new fossil species of the Australian endemic genus Peradenia Naumann & Masner (Hymenoptera: Proctotrupoidea, Peradeniidae) from Baltic amber.  Insect Systematics & Evolution 32: 191-194.

Masner, Lubomir, Norman F. Johnson & Andrew Polaszek. 2007. Redescription of Archaeoscelio Brues and description of three new genera of Scelionidae (Hymenoptera): a challenge to the definition of the family.  American Museum Novitates 3550: 1-24. (available online here)

Johnson, Norman F., Luciana Musetti, and Lubomir Masner.  2008. The Cretaceous scelionid genus Proteroscelio Brues (Hymenoptera: Platygastroidea).  American Museum Novitates 3603: 1-7. (available online here)


About the Author: Dr. Norman Johnson is Professor of Biology and Entomology with appointments in EEOB and Entomology. He’s also the Director of the Triplehorn Insect Collection. Norman works with minute, but crucially important, parasitoid wasps. You can learn more about his work by visiting the website of the Johnson Lab.

Collection moving day


As I mentioned in the previous post, we received the Parshall Butterfly Collection on October 15th. Here’s a quick account of the events of that day as I remember them.

It was a splendid Autumn day: dry, sunny, and cool.  Great weather to move an insect collection!  By the time I arrived at the Triplehorn collection (8:15 AM or so), Sara, Riley, KatherineB and Huayan were already there. Matt arrived right after I did.  Almost immediately after that Matt and Norman left to go pick up the 17-ft rental truck that we had reserved for the occasion. We decided on this size truck after calculating the total cabinet footprint of the Parshall collection. We also reserved a bunch of moving blankets (that’s what they are called) to serve as padding and protection for the cabinets.

When Cody arrived, we loaded ‘Dale’ (that’s what we call our heavy duty hand truck) plus all the other supplies we thought we were going to need (bubble wrap, packing tape, cardboard boxes, box cutters, scissors, rope, king size markers, plastic bags) and rolled away. Sara stayed behind to hold the fort and to get the home team ready for the unloading of the Parshall collection when we got back.

Riley, KatherineB, Cody, Huayan, and I arrived at Dave Parshall’s house a little before 10 AM. Norman and Matt had just arrived with the (large!) moving truck.  Dave was waiting at the door. He was excited to pass the collection on to us, but understandably sad to part with it. We got right to work.

Splendid day to move an insect collection.

Splendid day to move an insect collection.

The collection was in a dedicated room up two flights of carpeted stairs — they did not look as steep and narrow the first time I was there. Oh, well.

The pinned specimens were stored in two ways: 1) in drawers inside (three different size) cabinets and 2) in regular and large size Schmidt boxes (wood boxes with hinges and tight-fitting lids).

The papered specimens were stored in miscellaneous boxes that were already packed in large cardboard boxes. We started by moving those boxes downstairs and out of our way.  Next, KatherineB, Riley and I started preparing the Schmidt boxes for transportation. I’ll only say this: that process involved lots of bubble wrap and shrink wrap.

Meanwhile, Matt, Norman, Huayan, and Cody started moving the cabinets down the two flights of stairs — the carpet helped!

The two groups worked quickly and efficiently. By 1 PM we had the collection safely packed into the truck, which, by the way, was full almost to the door.

Before heading back we took a well-deserved lunch break at this small (and great) Greek restaurant located on a strip mall right across the street from Dave’s house — a sweet find.

Tummies full, we drove back to the Museum and got there around 2 PM. Our home crew (Sara, Lauralee, Cherokee, Alex, Gisele, Zach, and KatherineN) was ready to help unload the truck. Together we moved everything safely and in record time. By 3:00 PM the Parshall Butterfly Collection was neatly stored in our temporary quarantine area. The freezing process was scheduled to commence the next week.

A quick peak at the collection:

I went around opening random cabinets and boxes for a first view of the collection. Here’s some of what I saw:


Big thanks to our dedicated, skillful and overall amazing undergraduate curatorial assistants: Matt Elder, Riley Gott, Katherine Beigel, Cody Cardenas, Zach Hunt, who came in during their Fall Break to help with the move.  They worked long hours and could not have been more professional! Thanks also to our fantastic interns and volunteers: Alex DeMilto, Cherokee Hill-Read, and Lauralee Thompson, who generously give their time, knowledge and enthusiasm to the benefit of the collection. A special thank you to the graduate students in the Johnson lab: Huayan Chen, Gisele da Silva Katherine Nesheim, who put their own research aside for a day to provide support to the staff of the collection during this move. Finally, thanks to Sara Hemly, our Curatorial Technician, for her always efficient work.


About the Author: Dr. Luciana Musetti is an Entomologist and Curator of the (now significantly larger and more valuable) C. A. Triplehorn Insect Collection at The Ohio State University.