Department or Program



Ants, like other ectotherms, rely on heat from the environment to increase body temperature, and therefore, metabolic rate. However, critical thermal maximum (CTmax) and the capacity to acclimate to high temperatures is highly variable between species and affected by a variety of factors, both biotic and abiotic. First, I gathered CTmax values previously published for a multitude of United States ant species, and found that CTmax has a statistically significant, though weakly correlated, relationship with latitude. No phylogenetic signal was detected. This may suggest that local microclimate is more influential than latitude in determining thermal tolerance, although it is unclear whether this is due to local adaptation or plasticity. In light of these findings, I performed a common garden experiment to elucidate the patterns that determine thermal tolerance at a finer scale. The yellow meadow ant Lasius nearcticus is entirely subterranean and inhabits wooded areas, while the invasive pavement ant Tetramorium immigrans is a generalist, often inhabiting urban areas and foraging aboveground. I hypothesized that T. immigrans would display greater plasticity in response to acclimation at a high temperature as well as a higher CTmax. The mean CTmax value of T. immigrans was 7.4 percent higher than that of L. nearcticus (pmax findings support my hypothesis, the results of the respirometry measurements suggest that L. nearcticus may display greater plasticity, but that this may be advantageous for T. immigrans.

Level of Access

Restricted: Embargoed [Bates Community After Expiration]

First Advisor

Bavis, Ryan

Date of Graduation


Degree Name

Bachelor of Science

Number of Pages


Components of Thesis

1 pdf file


Available to Bates Community via local IP address or Bates login on Tuesday, March 30, 2027.