bumble bee gut bacteria and their responses to stressors
Creating "gnotobiotic" bees for experiments
Bumble bees are major pollinators and rely on specialized, coevolved gut bacteria for nutrition and protection from disease. A few species are reared commercially for crop pollination, and all are an important component of our native biodiversity. Funded by a fellowship from the USDA National Institute of Food and Agriculture, I am examining whether environmental stressors--such as parasites and rising temperatures--could be harming bumble bees indirectly by disturbing their gut bacteria. To do so, I am using bacterial growth assays in vitro and experiments with lab-reared bumble bees and genetically engineered symbionts. Numerous species of bumble bees are declining, as are many native bees and insects in general. This work will illustrate how microbial symbionts can influence host responses to climate change and other anthropogenic impacts on the environment, and may lead to information or tools to help manage and conserve bumble bees.
structure and function of gut MICROBIOMEs in Adult HELICONIINE BUTTERFLIES
Heliconius erato in Gamboa, Panama
In collaboration with Owen McMillan, I am studying the microbial symbionts and parasites of neotropical passion-vine butterflies (Heliconiini). Heliconius and related genera are a widely studied model system for the evolution and genetic/developmental basis of wing coloration. These butterflies also present an intriguing life history shift: Heliconius are unique among butterflies in their ability to consume pollen as adults (and thus acquire essential amino acids), and correspondingly have a long adult lifespan relative to other genera. However, very little is known about the microbial associations of heliconiines--particularly in the adult stage. I recently posted a preprint that describes the structure of adult gut microbiomes (including novel eukaryotic parasites) at different scales, from individuals within a population, to species and diet guilds. This study sets the stage for future experimental work testing how microbiomes intersect with host life history traits and diet shifts.
microbial mutualism in ground-nesting cellophane bees (colletidae)
Crawfordapis luctuosa in Monteverde, Costa Rica
Most of the ~20,000 bee species are solitary, where individual females provision their offspring with food. These provisions are a critical microhabitat and resource for bee development, and may contain microbial inhabitants that contribute nutrients, detoxification, defense, or other services. Funded by National Geographic, I recently began a foray into the microbial associates of the Diphaglossinae (Colletidae), also known as fork- and feather-tongued bees. In particular, I am particularly interested in the microbiology of rare, neotropical, ground-nesting Ptiloglossa bees, which have unusually microbe-rich larval provisions. Fieldwork is ongoing, so stay tuned for more updates about this project!