Abstract
Differential survival and development rates were obtained for the bertha armyworm, Mamestra configurata Wlk., reared at nine constant temperatures. Eggs and larvae had high survival rates at temperatures ranging from 8 °C to 32 °C and pupae showed good survival between 8 °C and 28 °C. Eggs and larvae did not complete development at 6° and 36 °C; and 32 °C was lethal for pupae. Duration of the egg, larval, and pupal stages decreased as the temperature increased from 8 °C to 28 °C. When duration and developmental rates were plotted against temperatures, the observed points did not differ significantly from curves formulated from the logistic equation 1/y = K/(1 + ea−bx). With a developmental threshold of 7 °C, 82, 356, and 352 accumulated day-degrees above the threshold were required for development of eggs, larvae, and pupae, respectively.