Researching Pelecinids – Part 4

image of author extracting DNA

The author learning DNA extraction protocols

Over the last several weeks, I have been hard at work with my research on Pelecinids. I continued to collect weekly samples from the Triplehorn Insect Collection’s malaise traps, and I began to practice keying various families and superfamilies of Hymenoptera. I also learned the protocols for DNA extraction, PCR, and gel electrophoresis from graduate student Huayan Chen.

Not every aspect of research, however, is an active endeavor taking place in a lab or in the field. Research also requires a considerable amount of time for reading, writing, planning, and patience.

I am now in the process of shaping my research into an honors project that will span multiple semesters rather than this summer alone. Honors research is a much more demanding ambition than a single semester of research, but it is also a very rewarding experience that will push me to delve deeper into my research topic. I plan to expand the scope of my current research on Pelecinus DNA by also looking for DNA from Wolbachia, a bacteria that can influence sexual differentiation in insects. Huayan and I have already found that Wolbachia is present in several of our wasp specimens. I am also interested in the possibility of geographical parthenogenesis in P. polyturator females.

My current focus is on composing an honors project proposal. The purpose of the proposal is to establish how I plan to conduct my research, what materials I will need, and what goals I aim to meet. The proposal also includes an abstract, which is vital for exhibiting my research to the scientific community, and a literature review, which is important for ensuring the quality and relevance of my project.

The literature review has proven to be the most challenging portion of the proposal. It involves finding and reading the research of others, then synthesizing the information into a concise review and citing the sources in a list of references. Because there is such a vast amount of previously conducted research available to read, picking out the relevant studies and piecing the information together can be a time-consuming process. While searching for material to read, it isn’t uncommon for me to feel a little overwhelmed.

Despite the challenge, the literature review is one of the most important components of any research project for many reasons. First, it prevents the unnecessary repetition of collecting and interpreting data that another study already collected and interpreted in an identical manner. Second, it provides helpful context for the researcher. By reading about work that others have done on Pelecinus, Wolbachia, and parthenogenesis in Hymenoptera, I will be better equipped to design a procedure that is effective and efficient, or modify that procedure should something not work. Third, I can interpret data from other studies in relation to my own research findings, and vice versa, leading to a more comprehensive understanding of my final results.

image of P. polyturator

P. polyturator female

Although summer semester is coming to a close, I still have several research-related plans before I head back to classes this autumn. I will collect fresh P. polyturator specimens from Zaleski State Forest this August, which is when adults are most prominent in Ohio. These specimens will then be used for DNA extraction, along with several frozen or mounted specimens already in the collection. We also received a generous donation of West Virginian and Canadian P. polyturator specimens, which will be very useful for sampling DNA from a wider range of localities. I will also continue collecting from the malaise traps, keying Hymenoptera families and superfamilies, and reading relevant materials on DNA barcoding.

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 3

A misconception that I often hear regarding research is that it only takes place inside a laboratory. Although procedures such as PCR and DNA barcoding do take place inside the lab, there is also an in-the-field component that is vital to producing quality molecular research. In order to analyze the DNA of specimens, it is first necessary to collect those specimens. While I research pelecinids in the molecular lab, I will simultaneously learn about the process an insect collection goes through to collect, curate, and document new specimens that can then be made available for research.

image of malaise trap

A malaise trap located at Waterman Farm

One of the most effective means for collecting large quantities of insects in a short amount of time is the malaise trap. These large traps consist of a black mesh base and a white mesh tent. At the peak of the tent is an empty plastic bottle attached to a second bottle full of ethanol. Insects flying close to the ground become caught in the mesh and instinctively climb upward to escape, leading them into the empty jar. The ethanol vapors then knock out the insects and cause them to fall into the ethanol bottle (Vogel, 2017). Not only does the ethanol preserve the specimens, it also makes collection very simple. All one must do is detach the bottle of ethanol and empty it into a storage container such as a Whirl-Pak, then refill the bottle with fresh ethanol and reattach it for further trapping.

The Triplehorn Insect Collection sets up three Malaise traps during the warmer months, one near the Carmack parking lots and two at Waterman Farm. Each trap is set up in a different environment, so each trap collects a different variety of insects. For example, the Carmack trap is located near a pond and collects damselflies, whereas the Waterman Farm traps do not typically collect damselflies because they are located in dryer areas.

Although the traps are mostly intended for flying insects, other organisms such as spiders and ants often climb up the mesh and meet a similar fate. Pelecinid wasps will occasionally find their way into the traps, but it is not a very common occurrence. I will have the opportunity to collect from more Pelecinus-rich habitats later this summer.

I learned how to collect from these malaise traps from Huayan Chen, one of the graduate entomology students conducting research at the collection. In addition to learning how to empty and refill the ethanol bottles, I also learned that I need to cut back the weeds that grow around the traps and how to tie the knot that secures the bottles (a feat which took an embarrassingly excessive number of attempts for me to master). As part of my research experience, it is now my responsibility to collect the specimens from each trap once every week for the next several weeks. Each sample, which must be labelled with the collection date and locality, then gets stored in one of the collection’s freezers.

These samples will eventually get sorted into separate vials for each insect Order. What happens next depends on the goals of the collection. Some vials may be stored in the freezer for future use. Others will be further sorted to Superfamily or Family. They can then be further identified, mounted into the collection and databased, or used in molecular work.

I will use the Hymenoptera from these samples to learn the process of adding specimens to the collection. My plan is to further sort some of these specimens by Superfamily or Family (or even genus!), mount and label them, and enter them into the HOL database. In addition to teaching me the full collection process, this will also provide me with a better understanding of Hymenopetera morphology and identification that will be invaluable for the rest of my research.

Vogel, Gretchen. (2017). Where have all the insects gone? Science, 356 (6338), 576-579.


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 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.

New beginning for butterflies & moths

Butterfly backlog at Ohio State

Butterfly specimens from the 1880’s that have been just mounted and still need to be sorted

The first curator of the Triplehorn Insect Collection at Ohio State, Josef Knull, was appointed in 1934, over 82 years ago. The core of the collection at that time was mostly the working collections from faculty and students, and the large Wenzel Beetle Collection that was acquired in 1925.

Now, Joe Knull was a ‘beetle guy,’ specialized in wood-boring beetles. He collected all insects, including butterflies and moths, but his main efforts were concentrated on the Coleoptera. Joe’s wife, Dorothy, had a PhD in Entomology from Ohio State. Her interest was the leafhoppers. She studied under the supervision of Herbert Osborn and collaborated with Dwight DeLong. Together these three specialists left us a massive collection of leafhopper types that is second only to that at the U.S. National Museum in Washington, DC.

By the time Joe Knull retired the collection had grown to number over 1.5 million specimens, most of them collected and preserved by Joe and Dorothy (as a volunteer) in their 28 ½ years of service. After Knull came Charles Triplehorn, another ‘beetle guy’. He was curator for 30 years and had many students. No wonder we have such a significant beetle collection!

The OSU collection kept growing. We became one of the largest university insect collections in the country, an active research and education facility focused on insect taxonomy and systematics, and a valued resource to scientists in the USA and abroad. But we have never been known for our Lepidoptera collection. It’s just how the chips have fallen. The insect groups that were actively being studied by faculty or students, especially beetles and leafhoppers, grew faster, became well-known, were borrowed and studied by more scientists. To be fair, three significant Lepidoptera collections were added to our holdings over the years: the Tallant, the Leussler, and the Homer Price collections. But still we did not become known by our Lepidoptera collection … until recently.

Since 2011, we have received various small to medium size moth and butterfly donations, some quite important, like the Asher E. Treat Moth Voucher collection. In 2015 we received the massive Parshall Butterfly Collection (see my blog posts here  and here), with over 50,000 mounted specimens. As a result of these donations, we currently have many cabinets marked ‘Miscellaneous Unsorted Lepidoptera’ that have yet to be separated to family, genus and species. Unfortunately, we lack the expertise and the money to do that ourselves.

And there, my friends, lies my problem and the reason why I’m writing this. Our goal is to digitize the specimen data for all our butterflies and moths so the information is available online to anyone interested in Lepidoptera. But before we can do that, we need help to tackle the curation and identification of our Lepidoptera collection.

I am reaching out to the members of the Ohio Lepidopterists Society, a group that uses and understands the value of insect collections, in the hope that some of you will be interested in helping us achieve our goals.

Lepidopterists can help the OSU insect collection by providing identifications for some of our many unsorted butterflies and moths. Or by simply helping us reorganize them. There is a lot of manual labor that goes into the curation of a collection: moving specimens (sometimes repairing them), labeling unit trays, drawers and cabinets, and organization. And the final stage of publishing all the data on the Internet also takes labor in transcribing specimen labels, putting latitude and longitude values on collecting localities, and uploading to the database. There aren’t enough hours in a day that would allow me, personally, to do everything. But volunteers can have a tremendously positive impact, especially experienced volunteers.

Collections document the biodiversity that makes the world such an interesting place, and in the long run help us to understand nature and to make wise, evidence-based decisions on conservation and enhancement. Please contact us if you are interested in donating some of your time, energy, and knowledge to help improve our Lepidoptera collection.

If you’re unable to make a gift of your time, you can also do the next best thing: please consider a monetary gift to our Friends Fund. The money goes directly to the collection for the support of student workers and for the purchase of specimen trays, drawers, pins, etc.

Thank you!

This article was first published in the December 2016 issue of the Ohio Lepidopterists Newsletter as “A new beginning for Lepidoptera at the Ohio State Insect Collection.” Posted here with minor editing.

About the Author: Luciana Musetti is an Entomologist who studies parasitoid wasps & and the current Curator of the Triplehorn Insect Collection.