Temperature Effects on Larval and Pupal Development, Adult Emergence, and Survival of the Pea Weevil (Coleoptera: Chrysomelidae)

Effects of temperature on the larval and pupal developmental times, adult emergence times, and survival of the pea weevil, Bruchus pisorum (L.),were examined at a range of constant temperatures. This study provided an alternative approach to analyzing stagefrequency data for determining stage transition times. It differed from the nearest published method in two vital areas: stage frequencies were expressed as the inverse of the proportion of insects in the sample that had not reached the relevant stage; mean-stage transition times were estimated by fitting a nonlinear curve to the changes i proportions with time. Mean developmental times for instar II, III, and IV, and mean adult emergence times were obtained by subtracting the estimated mean stage transition time from the mean of the previous stage. Temperature-mean developmental time relationships were described with nonlinear functions, which provided curves with a good fit, with r 2 ranging from 0.964 to 0.998. Mean developmental times were 3- to 5-fold longer for instars III and IV than for instars I and II.