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.

Two gorgeous gasteruptiid wasp species found in Antrim Park, Columbus.

 

Gasteruptiidae wasps are some of the most peculiar among the parasitic wasps. Larvae of gasteruptiids are predators (eat the host) or predator-inquilines (feed on the host and the host’s food storage, also known as kleptoparasites) in nests of solitary bees and wasps. Females lay eggs in the host nest; the hatched larvae may feed on the host’s eggs, larvae and on their food stores (Zhao et al. 2012). Adults are usually found around the nesting sites of their hosts such as dead tree trunks and clay banks, as well as on the flowers of plants in the carrot and parsley family (Apiaceae).

This small family of parasitic wasps in the superfamily Evanioidea (order Hymenoptera) contains only about 500 described species worldwide, although the real number of species is estimated to be 3-4 times larger (Jennings and Austin, 2002).

To date, only fifteen species, all in the genus Gasteruption Latreille, have been recorded in North America (Smith 1996).  So, I would expect these insects to be difficult to find around here and I would certainly not expect to find more than one species of these wasps visiting the same kind of flower at the same time. But, to my delight, Columbus always gets to surprise me! Just the other day, at Antrim Park, I found at least two species of these fascinating wasps visiting the flowers of a plant I identified as Golden Zizia (Zizia aurea), in the family Apiaceae. This plant, also known as Golden Alexanders, is a native prairie species that, in our area, will bloom from spring to early summer.

You can observe these elegant gasteruptiid wasps too if you are interested. They are usually dark in color, contrasting sharply with flowers they feed on. They are very easily recognized by 1) the slender and long abdomen that attaches high (dorsally) on the thorax, 2) the very long and thin ovipositor (not a stinger as these wasps do not sting), 3) the long “neck” that connects the head to the body, and 4) the swollen hind tibia.

So, next time you are cycling or jogging along the Olentangy Trail, check out the flowering Golden Zizias and look at these gorgeous wasps.

Female Gasteruption assectator (L.) foraging on Zizia aurea flowers.

A female Gasteruption assectator (L.) foraging on Zizia aurea flowers. You can tell it’s a female by the presence of the ovipositor.

Male Gasteruption assectator (L.) foraging on Zizia aurea flowers

A male Gasteruption assectator (L.) foraging on Zizia aurea flowers.

A female Gasteruption sp. foraging on Zizia aurea flowers

A female Gasteruption sp. foraging on Zizia aurea flowers.

A male Gasteruption sp. hovering around Zizia aurea flowers

A male Gasteruption sp. hovering around Zizia aurea flowers.

Golden zizia,

Golden Zizia, Zizia aurea, blooming in Columbus.

Acknowledgments: Thanks to Luciana Musetti, Curator, Triplehorn Insect Collection, OSU, for the help in improving the manuscript.

About the Author: Huayan Chen is an Entomology graduate student in Norman Johnson‘s Systematics Lab here at The Ohio State University. He studies tiny parasitic wasps in the family Platygastridae (Hymenoptera), but is interested in all sorts of insects. All photos courtesy of Huayan Chen. For more insect photos taken by Huayan, please visit his Flickr site.

References:

Smith, D.R. (1996) Review of the Gasteruptiidae (Hymenoptera) of Eastern North America. Proceedings of the Entomological Society of Washington 98: 491-499.

Jennings, J. T. & A. D. Austin. 2002. Systematics and distribution of world hyptiogastrine wasps (Hymenoptera: Gasteruptiidae). Invertebrate Systematics 16: 735–811.

Zhao, K., van Achterberg, C., and Xu, Z. (2012) A revision of the Chinese Gasteruptiidae (Hymenoptera, Evanioidea). Zookeys 237: 1-123.