How One Entomologist is Exploring the Insect Diversity of Prairies
By Karl Roeder, Ph.D.
Editor’s Note: This is the next post in the “Standout ECPs” series contributed by the Entomological Society of America’s Early Career Professionals (ECP) Committee, highlighting outstanding ECPs that are doing great work in the profession. (An ECP is defined as anyone within the first five years of obtaining their terminal degree in their field.) Learn more about the work ECPs are doing within ESA, and read past posts in the Standout ECPs series.
Rebecca Prather, Ph.D., is a postdoctoral researcher in the Department of Biological Science at Florida State University. Her current research at the Rocky Mountain Biological Laboratory focuses on phenological shifts of multiple taxa in response to various climatic factors. Previously, Rebecca earned a Ph.D. in ecology and evolutionary biology with Michael Kaspari, Ph.D., at the University of Oklahoma by examining how various environmental drivers structure insect communities in prairie ecosystems. Below, we ask Rebecca a few questions about her research and why she is interested in prairies.
Roeder: Were you always interested in insects?
Prather: Pretty much. As a kid I spent most of my recesses hunting for caterpillars or other insects, and I remember getting in trouble for ruining several outfits with lots of mud while I was digging for insects. Through most of my childhood, I spent a lot of time outdoors exploring the natural world.
As I approached college, I did not know of any careers studying insects, so I decided I would study biology and become a doctor. My second year of college I took an ecology course, and mid-semester my ecology professor invited me to work in his lab. On my first day, he showed me an ant colony under a microscope. Seeing an insect that closely was a transformational experience for me and solidified my love of insects, especially of ants. Through talking to my professor, I learned that research was a viable career option and knew that was the route I wanted to pursue.
I began working on my own research project in the lab, studying inter- and intraspecific competition in two acorn-dwelling ant species, Temnothorax curvispinosus and T. longispinosus. The more I learned about ants, the more I fell in love with them. As I approached my final year of undergrad, I began looking into ant ecology labs for graduate school, and the rest is history.
During your Ph.D., you worked a lot with insect communities in prairies. Why were you interested in that topic?
From my undergraduate research experiences working on leaf litter ants, I knew I wanted to do a dissertation that was heavily based on field work. Prairies were an obvious place to begin, as they are all around Oklahoma.
The first summer of my Ph.D., I wanted to better learn the local grassland ant species, so I started a weekly baiting project examining foraging preferences for different nutrients. I baited once a week at three separate times of day to try and capture the entire ant community. I ended up continuing this project for 8 months and, during that time, became more interested in not just ants but in the many insects and interactions happening in grasslands.
Specifically, I became more interested in all the interconnected drivers that determine insect community structure, and I wanted to know how these communities will be affected by future climate scenarios and anthropogenic effects like nutrient runoff. I love prairies because from a distance it seems like not much is going on, but when you stop and take a minute you see hundreds of interactions between insects occurring in any given moment.
If you continued to work in prairie ecosystems, what question, hypothesis, or topic interests you the most? And why?
Food quality including macro- and micro-nutrient concentrations available to herbivores and pollinators interests me. I am fascinated by how different plants acquire nutrients and how that in turn can affect the insect community. During my Ph.D., I started a literature search on grassland fertilization experiments, which turned into a meta-analysis examining how nutrients affect grassland insects across trophic levels. From that, I learned that micronutrients are understudied in field experiments and that not much is known about how pollinators respond to micronutrients.
As we all know, pollination is a key ecosystem service provided by insects, so going forward I’d be interested in studying how micronutrients might alter plant traits and how those varied traits affect pollinators and pollination rates.
What is the most interesting research challenge that you have encountered, and what was your approach to solving it?
During my Ph.D., I was working on a project studying foraging risk versus reward with the red imported fire ant (Solenopsis invicta). Specifically, I was interested in how far a worker would travel to reach foods of different quality if there is a high likelihood of overheating and death while foraging. The idea was that workers would only be willing to risk death if the reward was good (i.e., high-quality food).
I first tried using a diet common in lab nutrition experiments, which consisted of sugar and protein in an agar base, with the idea that I could dilute the amount of sugar and protein to change bait quality. However, when I did a trial run, I couldn’t get a single ant to forage on even my high-quality bait placed right next to a nest. I knew I needed to try something else, so I went back to the drawing board and decided I could simply use sugar water baits with different sugar concentrations, as I had previously used those to effectively bait other ant species.
When I tried out a sugar bait, I attracted all the species in my study area except for S. invicta. At this point, field season was rapidly approaching and I was beginning to panic. I read more studies and noticed that hotdogs were often used to bait S. invicta, so I tried putting hotdog slices out and got numerous S. invicta at my baits. Now I had a diet that would attract fire ants but did not know if I could pursue my initial line of inquiry because I thought I wouldn’t be able to change hotdog quality. I mentioned this dilemma to my husband, and he responded, “Why can’t you dilute a hotdog?”
His question made me re-examine my assumptions. If I put a hotdog in a blender, I could mix different amounts of hotdog paste into an agar solution to achieve baits of higher and lower quality. I tried these baits and found to my delight that I could get S. invicta foraging on my three different baits! I was able to use those baits to run my experiment that field season. Less delightedly, I haven’t wanted to so much as look at a hotdog since. Overall, that challenge helped me use more out-of-the-box thinking to solve other problems that arose in fieldwork during my dissertation.
As a postdoctoral researcher at FSU, you have shifted gears and are now working with long-term data and phenological shifts. Could you tell us more about the main goals of your current research?
My current postdoctoral research focuses on understanding how climate change is affecting an organism’s phenology. I have two ongoing projects.
First, I am working on maintaining a long-term flower phenology dataset. Researchers at the Rocky Mountain Biological Lab (RMBL) have been collecting data on plant phenology in the same plots since 1973 with the goal of examining how phenology has changed over time with climate. This project involves collecting phenology data each summer at RMBL to continue building the dataset. Working in montane grasslands is very different from the mixed-grass prairies I worked in during my dissertation. I like all grasslands, but I have to say I do enjoy the cooler weather during fieldwork in Colorado.
Second, RMBL has many principal investigators (PIs) who have been collecting data on the abundance and phenology of a variety of taxa for many years. I am working with those PIs on two synthesis projects. For the first project, I am examining how phenology is changing across taxa based on different climate drivers. It is neat to see that some drivers affect plants, insects, mammals, and amphibians, while others only affect insects, for instance. For the second project, I am working on examining how abundance of different taxa has changed over time based on climate drivers. Both projects are exciting, and it has felt good to be able to use the coding and statistics I learned during my dissertation.
How has the shift from your dissertation work to your postdoctoral work been? Any advice for graduate students making that transition?
During my dissertation, I learned a lot about how insects are responding to abiotic stressors in prairies. As I approached the end of my graduate studies, I felt like I had a good grasp on insect community ecology but was missing a deeper understanding of plant community ecology. I knew I wanted to continue studying plant-insect interactions after my Ph.D., so I tried to find a postdoc that would help me fill in my knowledge gaps.
The transition was challenging at first because I had a lot of new literature to grasp, and, with the brief nature of postdoc positions, I needed to get up to speed as quickly as possible. I built a strong community in graduate school, so on a more personal level I found transitioning to a postdoc in a new state during the pandemic difficult, as it has been harder to make new connections. My advice to graduate students making the transition to a postdoc is to be kind to yourself and give yourself time to adjust to the new lab, town, and potentially new study system.
Finally, what is your favorite insect and why?
My favorite insect is Temnothorax curvispinosus. I studied this species during my undergrad, and it was through my time working on it that I discovered my passion for community ecology. I am fascinated in general by cavity-nesting ant species, especially ones that nest in old acorns or twigs previously inhabited by other organisms.
Thanks Rebecca! You can learn more about Rebecca’s work at her website: https://rmprather.wordpress.com/.
Karl Roeder, Ph.D., is a research entomologist with the USDA-Agricultural Research Service in Brookings, South Dakota, and the North Central Branch representative to the ESA Early Career Professionals Committee. Email: email@example.com.
All photos courtesy of Rebecca Prather, Ph.D.