Meeting Abstract
Terrestrial ectotherms commonly use both physiological and behavioral strategies to avoid extreme temperatures and to maintain body temperatures within a thermal range that improves growth, development and survival. Developmental temperatures can alter maximum growth rate and optimal body temperatures, and ectotherms may use thermoregulatory behavior to maintain preferred temperatures for their relative optimum. Do developmental temperatures also affect thermoregulatory behaviors? We address this question using the Tobacco Hornworm, Manduca sexta . We reared larvae after hatching in either constant or diurnally fluctuating thermal conditions and tested at the 4th (of 5th) larval instar. To determine their preferred temperatures, larvae were placed on a gradient plate and subjected to either increasing or decreasing temperatures for one hour. Initial results suggest that while larvae from both rearing treatments respond behaviorally to escape high temperatures, they do not respond to low temperatures. We are continuing investigations to understand the contribution rearing history may have in modifying these behaviors.
