Developmental Rates of the Navel Orangeworm (Lepidoptera: Pyralidae) at Various Constant Temperatures

Abstract

The rates of development of the egg and pupal stages of the navel orangeworm, Amyelois transitella (Walker), were measured at various constant temperatures. Estimates of the lower and upper developmental threshold temperatures and thermal constants for the egg and pupal stages were 13.6, 32.2-34.4°C, 52 degree-days (DD), and 12.9, 32.2-34.4°C, 111 DD, respectively. Analyses of these data combined with data from other sources produced estimates of lower threshold temperatures and thermal constants of 13.3°C and 53 DD, and 12.9°C and 113 DD, for the egg and pupal stages, respectively. Diel periodicity of adult eclosion was documented; most adults eclosed near the onset of the dark cycle.