Does the heat turn caterpillars into cannibals?
Contributed by: Kale Rougeau (they/them)
Keywords: Abiotic stressors, Agriculture, Agroecosystem, Animals, Behavior, Behavioral Ecology, Climate change, Consumption, Disease ecology, Ecology, Environmental change, Experimental, First generation, Income, Interactions, LGBTQIA+, Mental health, non-binary, Queer, Societal Relevance, Terrestrial, transgender, Viruses
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Resources
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Notes
Slide 1: Researcher’s Background
Researcher’s Background
Kale Rougeau is a graduate student in the Systematics, Ecology, and Evolution division of Biological Sciences at Louisiana State University. They are a member of the Elderd Lab, a Disease and Quantitative Ecology lab. Kale’s research focuses on disease transmission, particularly how climate change and cannibalism might affect the spread of a species-specific baculovirus in the fall armyworm.
Why did you become a biologist?
I have always been interested in science and nature from a young age. Growing up, I would read extensively about various animal species in encyclopedias and online and write up fact sheets just for fun. I knew I didn’t want to work in veterinary medicine or pursue a job too closely related to my hobbies, so I mostly studied wildlife ecology in my undergraduate research. I realized I was very interested in ecology, so I continued my path to studying biology in graduate school at LSU.
What is your favorite part about your job?
My favorite part of my job is knowing that I am contributing to a greater overall understanding of the world. Knowledge is powerful, and all research contributes a little bit more knowledge to the general public, no matter how small. I think it’s fun to stay curious and interested in the world around us, and it’s important to keep asking questions and trying to answer them.
What obstacles have you overcome to get where you are?
As someone from a low-income background and a first-generation college student, I have always struggled with the financial barrier to higher education. I’ve never had a lot of money, and I’ve always had to work. At times, it has been difficult to succeed in my STEM career while worrying about my financial situation. This has sometimes impacted my grades, mental health, productivity, and overall success in the field. To overcome this obstacle, I have put an immense amount of effort into securing scholarships, grants, awards, and stipends from the moment I first applied to college. I am fortunate enough to have received many scholarships and grants to fund my education. To cover other living expenses, I have always chosen work avenues that are most conducive to my academic success, such as taking up student worker positions on campus during my undergraduate studies, being a Research Associate or Teaching Assistant to get paid while getting my master’s degree, and finding freelance gigs that work with my schedule. Through perseverance, hard work, and some gracious opportunities, I have overcome various financial hurdles to my education and will soon be working a full-time job in STEM.
What advice do you have for aspiring biologists?
I would tell aspiring biologists to choose a field that truly interests them, always be yourself, and surround yourself with supportive colleagues.
Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?
I am non-binary, transgender, and queer. These aspects of my identity certainly make me stand out from many others in STEM and society in general. I also come from a low-income background, and I am a first-generation college student, so I have struggled in terms of navigating finances and higher education in general.
Slide 2: Research Overview
Take home message of study
Kale is interested in seeing whether climate change will affect disease spread in fall armyworm caterpillars. Specifically, they want to see whether increased temperatures lead to an increase in cannibalism, potentially due to higher metabolic rates at warmer temperatures. Through a series of experiments, Kale found that the caterpillars did cannibalize more at higher temperatures, but the percent of cannibals that contracted a disease from infected conspecifics did not show a clear pattern with temperature.
Study system
Fall armyworms are an agricultural pest known for destroying corn, soybeans, and other crops worldwide. In the summer, they move into fields and rapidly chow down on crops. Believe it or not, their huge appetite leads them to another food source – they will even turn into cannibals and eat each other!
Photos
Top left: A fall armyworm cannibalizing a smaller one during the experiment.
Top right: A fall armyworm that has been liquified due to a baculovirus infection.
Bottom diagram: A visual example of the experimental treatments. In each Petri dish there is a large fall armyworm, a small fall armyworm (also called conspecific), and a chunk of insect food. Each combination had 20 samples set up in the same way. Image created in BioRender.com.
Slide 3: Key Research Points
Key figures
Results from Kale’s studies show that the percent of fall armyworms that cannibalized a smaller conspecific increased with temperature (top graph). Of the fall armyworms who cannibalized an infected conspecific, the percent that became infected did not show a clear pattern, with the highest incidence at the medium temperature.
Societal Relevance
Around the world, temperatures are rising from climate change. This is a hot topic for scientists because warmer temperatures could make diseases spread a lot faster. Many diseases spread when organisms consume different types of food that may have pathogens in or on them. With warmer temperatures, metabolisms increase, and organisms need to eat more food to survive. This increases the risk of organisms eating something that will get them sick. It is important to understand how climate change can have impacts that cascade through various ecological interactions and how the complex interconnected relationships in nature may play out in the future.
