Frost Curators' Blog

Musings and miscellanea from the Frost Entomological Museum

“That is really big for a one-celled thing!”

Last summer I was funded by the National Science Foundation to work at the University of Michigan Biological Station (UMBS) through a Research Experiences for Undergraduates (REU) program. I like to think of this time as the beginning of my broad appreciation for entomology. This also was the time that I began to find host-parasite relationships so fascinating. In my research I calculated gregarine parasitism in the damselfly Calopteryx maculata (Beauvois, 1805) and attempted to correlate those findings with stream characteristics of the habitat in which they were caught. My paper, which I recently submitted to a small research journal, specifically focused on the idea that climate change will dramatically affect freshwater ecosystems, and therefore the interactions between the aquatic insect hosts and their parasites. My stream measurements included stream flow, dissolved oxygen, pH, and water temperature. That part of my research, though very interesting in its own right, is not the focus of this blog post. Gregarines are!

Gregarine parasites are one-celled protozoa that can be found within a variety of insect hosts. These parasites attach themselves to the gut epithelium of a odonate after ingestion through drinking water contaminated with oocytes or eating prey physically carrying these protists on their bodies. Once attached to the gut, gregarines absorb food ingested by the host. As other researchers have found, if a host contains a large number of gregarines, those parasites could restrict food and shorten the host’s lifespan.

After hearing of my research, István Mikó was interested in seeing some of these little guys up close and asked me on our last field outing to try and collect a few Calopteryx maculata (Beauvois, 1805). I don’t like to disappoint entomologists so I set out on my task. Luckily the site we went to in Whipple Dam State Park had a stream that had several! After collecting a few unlucky damselflies, it was back to the lab to dissect. I have included a picture of one male damselfly to honor his sacrifice to our research.

Rachel holding a calopteryx maculata by the wings, up close.
Thank you Sir Damselfly. Rest in peace. Photo by R.Davis (CC BY 2.0). Click for source.

To dissect, we cut off the abdomen of the damselfly and carefully pull out the gut onto a glass slide with a small amount of distilled water. You can see the result of this in the picture below. Something to note about this picture is that you can actually see the protozoa with your naked eye! The small white flecks contained in the gut epithelium are the massive one-celled gregarines. It was no guarantee that this collecting site would have damselflies that hosted parasites but we got lucky!

A damselfly epithelium has been pulled out onto a glass slide and is ready to be observed for parasites.
You can see them with the naked eye! Photo by R.Davis (CC BY 2.0). Click for source.

István excitedly took the slide and began to set up the Frost’s imaging system for me. The pictures below are Brightfield images taken with an Olympus Compound Microscope.

High resolution photo of white gregarine parasites within a damselfly epithelium.
I think you should go get that checked out mate. You don’t look too good. Photo by István Mikó (CC BY 2.0). Click for source.
High resolution photo of gregarine parasites within a damselfly epithelium.
The things within. Photo by István Mikó (CC BY 2.0). Click for source.

Hopefully you can see how colossal these ONE-CELLED parasites can be! After counting these little guys on a rudimentary microscope last summer at UMBS this was an amazing experience and I hope you enjoy these high definition pictures as much as I did.

 

 

Light it up, up, up

A view of the room that stores the entomology collection at the Frost Entomological Museum. The collection is stored in the cabinets and there is a nice workspace near the front windows for curatorial projects and digitization.
Frost Museum Collection Space. On the left are unit trays for organizing and adding specimens to collection drawers. At the center left of the image are the cabinets which house a majority of the collection. At center right you can see that there is a nice work space near the front windows for curatorial projects and digitization. Photo by Isa Betancourt (CC BY 2.0)

This summer I’m digitizing the Syrphidae (Hover Fly) and Aculeata (Stinging wasp and bee) specimens of the Penn State University Collection. It’s my first time imaging insect specimens and their data as a primary focus of work. I’ve enjoyed trying out the gear and set ups here at the Frost Museum.

Below is a photo of the main set up that I use. The red tape lines allow software to sort the sections of the image into different categories: insect specimen, collection information, determination information, unique identifier (unique number and barcode), color and size reference, misc info, and photographer & repository names. The glass dish on the right serves as the unique identifiers pool. I take one out and place it in the photograph with the specimen. When returning the specimen back to it’s place in the collection, I put the unique identifier label on the pin with the original specimen information labels.

Lighting is key to obtaining an ideal image. I surrounded the subject area with white panels to help distribute and soften the light emitted from the fixtures. It doesn’t look very pretty – there are gobs of tape and pins holding different parts together – but it works. It makes a huge difference and greatly contributes to a pretty final image. What ever takes to properly light up the stage!

Pinned insect specimen digitization set up. A camera facing down at a platform. On the platform rests the specimen information and the pinned specimen itself. The area is surrounded with white panels and lit with muted light fixtures
Pinned insect specimen digitization set up. A camera faces down at a platform. On the platform rests the specimen information and the pinned specimen itself. The area is surrounded with white panels to help evenly distribute light and it is lit with muted light fixtures. Photo by Isa Betancourt (CC BY 2.0)

We came across a hurdle when it came to the color reference pad. The one we had was too big! It took up too much space. The focus is supposed to be on the specimen and information yet the color reference pad took up 1/3 of the frame.
The picture below is of one of the larger vespid wasps in the collection. If the color pad made that look small, there would surely be a size issue when digitizing the much smaller hover flies.

Pinned insect digitization layout with large color reference pad.
Pinned insect digitization layout with large color reference pad. Photo by Isa Betancourt (CC BY 2.0)

We ordered a smaller color reference pad. This one is about the size of a penny. Vertical space is the limiting factor when it comes to zooming into the image. I’ll probably readjust the arrangement by rotating the ruler to a vertical position and repositioning it to the left or right side of the color reference pad. That would allow me to shift the lower horizontal red border upwards.

Pinned insect digitization layout with small color reference pad.
Pinned insect digitization layout with small color reference pad. Photo by Isa Betancourt (CC BY 2.0)

 

We have a GIGAmacro robotic imaging system that we will likely use to collect a higher quality, stacked and stitched, image of a representative of each species. More on that system in a future post!

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Check out this Frost Museum Instagram post that features some of the images that are finished and ready for transcription:

Error: You are not good at GIS

I’ve been receiving a lot of error messages while attempting to model the distributions of the species I have been assigned on ArcMap. I took a semester of introductory GIS last fall but I don’t think it is helping.

This picture displaces a map of North America with locality data of specimen catches throughout.
The beginning of a very complicated process. Photo by R. Davis (CC BY 2.0).

That is all I have to share! Maybe next week I can gush about my models to you all. Currently however, I have a long way to go. I hope something gives!

The Trials of Translation– Tricky and Misleading Words

While translating Dessart’s texts, I found some words that were tricky to translate. I’ve listed some of the more amusing ones for your entertainment- enjoy!

Chagrine: The English word chagrine means “sorrowful”. Google Translate thought this was what Dessart meant as well, and I became confused about why Dessart kept describing so many sorrowful wasps. But what Dessart actually meant was “chagrined”, referring to the texture of the wasps. The error in translating chagrine was worsened by the fact that Dessart often describes the wasps as being sombre, which means “dark”; in this case, he means that the wasps are dark in color, not dark in mood.

Alutace: This was one of the first terms that gave me problems. Searches online could not reveal the translation or even the origin of this word. My grandfather dug out an old dictionary from his collection and was able to tell me that the term referred to the texture of book leather. After talking to István, I learned that the term alutaceous is commonly used among hymenopterists to refer to the texture of the cuticle.

Lyrees: It looks like lyre, but words don’t always mean what they look like (take chagrine or sombre, for example). Talking to István, however, we worked out that lyrees could mean “lyre- shaped,” referring to the dorsal sutures on megaspilids which do indeed resemble the shape of a lyre.

Can you see the lyre shape on the back of this Conostigmus specimen from Madagascar? Photo by István Mikó (CC BY 2.0).

Bombées: It looks like “bomb”, right? Or perhaps Bombus, to those bee fans out there? Google translated this word as “bomb” at first, but then I noticed that I forgot the accent over the first “e”, which changed the translation to “bent” or “rounded”. It makes much more sense to have a rounded mesopleuron than an exploding one.

You know what Assuming Does? Assuming Makes an… Acceptable Georeference of a Specimen?

A niche model can allow scientists to examine climatic preferences of a certain species by modeling their distribution. Certain factors such as precipitation and temperature allow us to examine those habit preferences. One might imagine that to construct something like this, it would require the very exact location of where a bird, mammal, or in our case, insect was caught. As I have explained before in previous blog posts, however, georeferencing the exact locations something is caught is not always possible to do- especially when you are processing specimens that were collected before a time that one could readily obtain GPS coordinates. Before you begin creating a niche model, I think it is important to understand that said niche model will never be perfect. You must leave your perfectionism at the door before beginning.

Below I will outline the steps I went through to find an acceptable (by my own standards) locality:

  1. Above, highlighted in yellow is a location that has not been easily found through a combination of Google Maps and Tulane University’s GEOLocate platform. I must now put some elbow-grease into finding Toplovich Bog.
This shows an excel file with multiple locations and coordinates. The row of
Only a few more localities to georeference. Photo by R. Davis (CC BY 2.0). Click for source.

2. A series of blog posts and travel sites tells me Toplovich Bog exists. There is even a field trip scheduled to visit Toplovich Bog next week. If anyone is interested, there is a group planning to leave from the Westfield McDonald’s parking lot at 9:30 AM on July, 16th. But they don’t give me coordinates. Thanks a lot!

3. With a few lucky Google posts I come across this map. This map details the recreation opportunities in Warren County. After reading that this bog was very close to the border on other websites, I began to look for any reference to Toplovich Bog. Do you see it? Upper left corner!

4. I now have a general idea of where this bog is. I can now begin to explore this area with Google Maps. If you reference back to the map, it shows that Toplovich Bog is underneath State Game Lands Number 197. We can even double-check ourselves by comparing the streets of the Warren County map and Google Map results.

This collage shows two separate pictures of the State Games Lands Number 197.
Exploring the area with Google Maps. Photo by R. Davis (CC BY 2.0). Click for source.

5. Now we are ready to Georeference this locality and get the coordinates. Using everything I know from previous information on the bog I can place a marker to obtain the coordinates of the general area. These coordinates will represent the location of the catch and is essential to our modeling. After all that interweb searching we are done! Only 300+ localities to georeference!

Using GEOLocate I was able to find the coordinates of the general area of Toplovich bog.
Finally! You have not beaten me locality! Photo by R. Davis (CC BY 2.0). Click for source.

So, I must ask, are my own standards acceptable? I started with a blog and worked my way up. Throughout my undergraduate career I was always told to be wary of less than reputable sources and strive to be near-perfect when carrying out an experiment. Is that attitude applicable in this field of science? I think realistically, we simply cannot perform at that level of perfectionism when georeferencing locations with no given coordinates. You can either assume a location to the best of your abilities or you can throw the sample out of your model. I would enjoy hearing other’s perspectives!

Department of Entomology, in the College of Agricultural Sciences, at Penn State

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