Meeting Abstract

100.4  Wednesday, Jan. 7  Does diet quality alter the temperature-size rule? DIAMOND, S.E.*; KINGSOLVER, J.G.; University of North Carolina, Chapel Hill; University of North Carolina, Chapel Hill sdiamond@email.unc.edu

How does variation in diet quality and temperature interact to affect survival, size and development time in herbivores? We conducted laboratory experiments with the tobacco hornworm, Manduca sexta, that were reared on typical (tobacco) and novel (devil’s claw) host plants at three constant temperatures (20, 25, and 30 C). Both field and domesticated laboratory populations of M. sexta were considered. Preliminary analyses suggest that survival on tobacco was relatively high (> 80%) at all temperatures for both populations; in contrast, survival on devil’s claw declined strongly with decreasing temperature, particularly in the laboratory population. Pupal mass and development rate were greater on tobacco than on devil’s claw at all temperatures. Pupal mass declines with increased rearing temperature for both populations reared on tobacco, in agreement with the temperature-size rule. However, preliminary results suggest that this pattern is obscured or reversed on devil’s claw. We discuss how diet quality may alter the associations among temperature, body size and development time in herbivorous insects.