Research

Urban Ecology

Insects play a dominant role in urban ecosystems in terms of both their abundance and diversity. Even in a city the size of New York, ants outnumber humans by 2000-to-one, and more than 40 ant species can be found within a 10-mile radius of the Empire State Building.

But the role insects play in urban ecosystems remains poorly understood—we have barely characterized insect diversity in cities, let alone the impacts of insects on nutrient cycling, soil health, pollination, disease transmission, and other ecosystem processes.

Working in places like New York City, we study the role human foods play in urban food webs and how social insects are adapted to urban life.

Social Immunity

Just like humans, social insects live in large groups with a high chance of disease transmission. Also like us, many social insects produce antimicrobials to keep their homes and bodies free from pathogens.

We developed a high-throughput assay to quantify the antimicrobials produced by social insects. While long held theory predicts that all social insects are likely to use antimicrobials, we’re finding that many species do not. We’re now interested in elucidating other mechanisms social insects use to defend themselves against disease, including potential partnerships with beneficial bacteria and fungi.

Fire ants produce the most potent antimicrobials identified to date in ants and other social insects.

Extracting putative antimicrobials from a carpenter ant. (photo: Lea Shell)

Cuticle surface textures may influence how well ants are able to clean themselves and could also potentially harbor beneficial microbes. (images modified from www.antweb.org)

Warming chamber at Duke Forest where we heated forest plots to simulate future climate warming over five years. (photo: James Waters)

Common garden study at NC State University's Phytotron where we reared over 400 ant colonies.

Pitfall traps used to sample arthropod communities across warmed plots each month at Duke and Harvard Forests.

Control center for Duke Forest warming chambers. (photo: James Waters)

Climate Change

For millions of years, species have faced changes in climate that have shaped their evolution and their biology. The result is that species display differences in key traits that can be used to estimate thermal performance and predict how species will respond to climate change. Our lab measures traits of social insects that allow us to predict their responses to warming in the field.

Much of this work began through research at the Duke and Harvard Forests warming sites, where we warmed forest plots over five years to identify changes in insect communities. We are now linking thermal traits to the individual performance of insect species in the field.

Nest Architecture

A hallmark of insect sociality is the construction of elaborate nests, which often house tens-of-thousands of individuals. Nests are vital for colony protection as well as regulating the internal micro environment.

Our research focuses on understanding the structure of insect nests as well as their biological functions. We are currently working with engineers at Arizona State University to study honeycomb nests in bees and wasps to improve 3D-printed materials for aerospace design.