Excuse the clickbait title, but you’ve got to see this! For the last few weeks I have been slowly chipping away at digitizing and updating the Odonata ethanol collection. There is an abnormal smell that I expect can only come from 50-year-old ethanol with rubber tops, but I am glad that these little guys can be put in new homes- with a plastic top! Rafa did a great job with the louses and now I am trying to do the same with the odes.
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.
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!
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.
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.
Andy Deans, the director of the Frost Entomological Museum gave us interns (guinea pigs) a challenge this week. Could we observe a 4×4 patch of land and its insect inhabitants for 4 hours and document our findings? Andy calls this experiment, “Discover[ing] Your Inner Darwin”. He told us that he drew inspiration for this challenge by reading an article in the Harvard Magazine entitled, The Power of Patience. In this article, art-history professor, Jennifer Roberts requires her students to engage in a similar practice- focus on one painting for 4 hours. Roberts describes this amount of time as “painfully long”, but crucial to her goal. She states, “What this exercise shows students is that just because you have looked at something doesn’t mean that you have seen it. Just because something is available instantly to vision does not mean that it is available instantly to consciousness”. I think this is what Andy was trying to get at. I might see a beetle or damselfly in a natural landscape but key details of its very existence may be lost if I only give it a brief amount of attention.
So I sat. While sitting I recorded my observations, hypotheses, questions, and sketches in the notebook provided.
I sat at a creek in Whipple Dam State Park and watched water striders (and a variety of other specimens) for about 4 hours. As expected, when forced to sit and observe for a long amount of time (without internet), you begin to formulate different questions and hypotheses than if you were to simply look at them and then begin to observe something else- something that I think we have all become very accustomed to in this age of rapid information. Rather than asking myself, “what is that insect?”, I began to ask, “Why is it behaving like that?”. It was hard for me to begin asking myself these questions because my undergraduate education was very focused on memorizing structures and names and not asking creative questions on behavior. During this experiment I even began delving into the big questions such as, “Why was that morphology evolutionarily beneficial and how did it come to be?”.
One thing I noticed was how territorial it seemed water striders are. I even wrote in my notebook, “The waterbugs [excuse my basic description] seemed very ‘respectful’ of each others space. If one begins to encroach then the other will usually begin to move in the opposite direction, almost like bumper cars”. I show my rudimentary sketch of this below.
I think there is something quite special about this experiment and Andy should be very proud of developing something like this for his students. It allows creative thought to flow freely. It allows students to escape distractions of their everyday life and get outside (perhaps even better than Pokémon Go – as I didn’t have cell service at Whipple Dam). It allows students to get comfortable with the feeling of being uncomfortable. The Internet and the age of rapid technology have absolutely benefitted us of course. Sometimes, however, one just needs to sit down and watch water striders for 4 hours to appreciate our eyes and minds at work.
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.
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!
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:
- 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.
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.
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!
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!
Do you know what a teenage dragonfly looks like? I will sheepishly admit that I did not know before starting at the Frost! The proper term for a young adult dragonfly that has just emerged is a teneral. The Latin root word of teneral, tener, means tender or young. After moulting, an insect is in the teneral stage. An arthropod in the teneral state is described as soft-bodied, as their new exoskeleton has not hardened yet. In addition, an Odonata teneral can often have a paler coloration than their mature adult counterpart. Therefore, one should be cautious about identifying species in the teneral stage, as the colorings can be very different and misleading. However, with an expert’s help in identification, we can see these extreme differences in the two pictures below of the Common Whitetail Dragonfly (Plathemis lydia, Drury, 1773).
Some might say that the dragonfly above is nothing special. But wait there’s more! In the picture below, do you see how the adult is so much more vibrant than its teneral counterpart? I guess the awkward teenage phase exists in dragonflies too!
After catching a teneral at Ten Acre Pond a few weekends ago I became very interested in this life stage of the dragonfly. You can see in the picture below that the dragonfly I caught had very shiny wings. It could not fly well and was an easy catch. Learning about the life stages of insects is fun, and I encourage budding entomologists to get out there, explore, and maybe find a few tenerals!