Kate Mathis, Ph.D., postdoctoral researcher at the University of Arizona and soon-to-be assistant professor at Clark University, studies complex species interactions, often focused on social insects in agricultural ecosystems. In the field, sometimes that means cutting open woody plants to collect twig-nesting ants.

By Monique Rivera, Ph.D.

Editor’s Note: This post is fourth 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.

Kate Mathis, Ph.D., is currently a postdoctoral researcher at the University of Arizona under Judith Bronstein, Ph.D. She will start a new position as an assistant professor at Clark University in the Department of Biology this fall. She has been an ESA member since 2010. Below, we ask Kate a few questions about her research, and we hope you will enjoy learning all about her multidisciplinary work.

Rivera: What would you say is the main goal of your research? 

Mathis: My lab works on a diverse array of questions related to the ecology of species interactions, agroecology, and community ecology. The central goal of my research is to examine the dynamics of complex species interactions and how they are shaped by managed systems. My research uses an integrated approach, combining observational studies, manipulative field experiments, chemical ecology techniques, and lab experiments. I am particularly interested in addressing questions whose answers will advance our basic understanding of ecological principles while also providing insight into real world problems.

I worked in several managed systems including coffee plantations, peach orchards, and rangeland using a variety of insect study organisms including ants, flies, beetles and bees. My research program currently focuses examining ant-plant defense mutualisms, which provide important ecosystem services in agriculture as well as natural communities.

Why did you choose to study entomology, specifically ants? 

I have chosen to study insects, particularly ants, for so many reasons over the course of my life, but I have to say that it began with peonies. My mother had these beautiful peonies in her gardens while I was growing up. Each spring they would bloom and, without fail, ants would swarm the opening flowers. I couldn’t find ants on any other plants in her garden, and I found this completely fascinating. What were they doing? How did they find the peonies every spring?

It wasn’t until much later when I took an Insect Ecology course in college that I discovered peony buds excrete sugary nectar that attracts ants, presumably so that the ants can ward off harmful herbivores during the early flowering stage. I also learned that ants interact with an incredible variety of other organisms in nature: some farm fungus; some harbor beetles, caterpillars, spiders, and roaches safely in their nests; some have fascinating parasites; and others have cool mutualisms with plants. There is an entire small yet complex world of interactions involving ants just waiting to be studied. I was hooked.

In one of her studies, Kate Mathis, Ph.D., developed a motorized platform to move dead, chemically neutralized ants along a track to test whether parasitoid phorid flies use movement as a visual cue to hone in on individual ants.

An Azteca sericeasur ant on a coffee plant in Mexico.

At one field site, Mathis collected ants with pitfall traps in the ground near trees in an Arizona peach orchard.

A view near the Finca Irlanda field station in the Soconusco region of Chiapas, Mexico.

Kate Mathis, Ph.D., (middle) at her Mexico field site with colleagues Esteli Jimenez-Soto (left) and Penelope Gillette.

Kate Mathis, Ph.D., and student Karen Wang conduct pollinator exclusion experiments on Mt. Lemmon in Arizona.

A lab colony of Azteca sericeasur ants used in Kate Mathis’ research.

An artificial extrafloral nectary attached to a peach tree attracts ants in research conducted by Kate Mathis, Ph.D.

What has been the most interesting research challenge you’ve approached, and how did you solve it? 

One of the coolest solutions to a research challenge was part of one of my first research projects. I was investigating the cues phorid fly parasitoids use to locate their Azteca ant hosts in Mexico. I had already found that phorid flies use the ant’s alarm pheromone to locate ants from a distance, but I hypothesized that the phorid flies were also using movement as a visual cue to hone in on individual ants.

Testing this hypothesis was tricky because so many variables needed to be controlled. I couldn’t use live ants because they might excrete additional chemical cues that could confound the results, and I couldn’t do the experiments in the lab because the phorid flies didn’t behave normally in confinement. So, I ended up building a field-ready motorized platform where dead, chemically neutralized ants moved along a track to test the hypothesis—and it worked! I found that phorid flies wouldn’t inspect ants that were still, but when the ants were in motion phorid flies would hover over individuals.

What is your favorite non-formicid insect? 

This is such a tough question! I have a big soft spot for rove beetles, particularly Myrmedonota xipe. Rove beetles are neat because many of them associate with ants in one way or another. Myrmedonota xipe is a species that I discovered, the first of its genus in Central America, and these beetles are attracted to alarm pheromones and prey on ants. In southern Mexico, these beetles are attracted in particular to the ubiquitous Azteca sericeasur ants, yet they’re only able to prey on Azteca ants that have reduced aggression from being parasitized by phorid flies.

It’s this fascinating case where these beetles are predators of the ants, but they’re only eating ants that were already doomed to die from parasitism and were harboring phorid flies. So, even though the beetles are predators, they might actually be beneficial to the ant colonies overall. This is why I named them Myrmedonota xipe, after Xipe Totec, the life-death-rebirth deity the Aztecs made human sacrifices to in order to ward off disease and bring health and prosperity to the community as a whole.

To learn more about Kate’s work, visit www.katemathis.org.

Monique Rivera, Ph.D., is a postdoctoral researcher at the University of Florida Citrus Research and Education Center and will begin a new role as assistant extension specialist at the University of California, Riverside, on July 1. She is also the Southeastern Branch Representative to the ESA Early Career Professionals Committee. Email: moniquejoyrivera@gmail.com

All images in this post courtesy of Kate Mathis.