Abstracts Biological Sciences

Regional-scale climate-induced variation in ant physiology and morphology

by Daniel E Murphy

The biology of ectotherms such as insects is influenced by ambient thermal conditions. Ants are a ubiquitous and ecologically important group of insects and are well-established as bioindicators of thermal conditions. Ants are sensitive to the thermal extremes that vary with latitude, elevation, and land use, and these thermal gradients influence their spatial and temporal distributions. As a result, ants have evolved physiological and morphological thermal adaptations in response to the thermal environment of their habitats. These adaptations include increased physiological and morphological tolerance for temperature extremes. In Western New York (WNY), temperatures are temporally and spatially heterogeneous, changing with the season and in distinct regional climate zones formed by gradients in elevation and proximity to the Great Lakes. Coastal areas are relatively colder in spring and warmer in fall than inland areas, and urbanized areas are relatively warmer year-round. The goal of this study is to assess ants as climate bioindicators by investigating the relationship between ant thermal traits and regional climate variation in Western New York. Though I investigated several ant species, my focus was on two regionally abundant ant species: Aphaenogaster picea (myrmicine) and Lasius americanus (formicine). I repeatedly sampled closed canopy and open areas during the early and late summer of 2020. Ants were tested for minimum and maximum physiological thermal tolerance (CTmin and CTmax) and ant leg length morphology was measured using a stereomicroscope.