Research

We study the population, community, and chemical ecology of mutualisms involving plants and insects. We use field and lab experiments, behavioral assays, analytical chemistry, and demographic modeling to answer questions such as:

1. How do mutualisms generate and maintain biodiversity?,
2. How does biodiversity affect the outcomes of mutualisms?
3. What are the broader population- and community-level consequences of biodiversity in mutualisms?

Ant-hemipteran mutualisms

Ant-hemipteran interactions are classic food-for-protection mutualisms. Ants protect sap-feeding hemipteran insects, such as aphids, against predators and parasitoids. In exchange, hemipterans excrete a sugary reward called "honeydew" that the ants consume. These mutualisms frequently involve dozens to hundreds of interacting ant and hemipteran species that can vary dramatically in their effectiveness as mutualist partners. One main line of research in the lab is focused on understanding the causes and consequences of biodiversity within ant-hemipteran mutualisms.

Seed dispersal mutualisms
Because plants are rooted in place, many plants produce fleshy fruits to attract animals that help disperse their seeds. Yet, fruits are also vulnerable to attack by seed predators and pathogens, perhaps explaining why fruits often contain high concentrations and diversity of toxic or deterrent secondary metabolites. Currently, the lab is investigating the role of fruit chemical trait diversity in shaping the broad range of species interactions surrounding fruits, as well as how plants may mitigate potential trade-offs between seed dispersal and fruit defense.

Bee gut symbioses

Pollination is vital for food production, yet key pollinators, including bumble bees, are declining at alarming rates. To stop these declines, we must find ways to promote bumble bee health. One promising approach is to improve gut microbiome functionality using probiotics. The bumble bee gut microbiome includes five common core bacterial species, which provide a number of benefits to bee health, as well as variable mixtures of non-core species. Composition of these bacterial species, and strains within them, varies extensively among bumble bees. Yet how this variation impacts host function—and whether it can be leveraged to support bumble bee health—are unknown. While most future research in the lab will focus on other mutualism systems, we are currently wrapping up work investigating the effects of gut microbiome diversity and composition on host health and function.