INFLUENCE OF TEMPERATURE AND MOISTURE ON BLACK CUTWORM (LEPIDOPTERA: NOCTUIDAE) DEVELOPMENT AND REPRODUCTION

Abstract

Influence of temperature and moisture on black cutworm, Agrotis ipsilon (Hufnagel), development and reproduction was studied on field corn. The black cutworm spends portions of its life above and below soil, consequently influence of temperature and soil moisture and temperature and relative humidity (R.H.) was determined. Temperatures of 34°, 27°, and 20°C were used with 18%, 24%, and 30% soil moisture and with 40%, 60%, and 80% R.H. In addition, a treatment of 13 °C and 60% R.H. was included.Temperature was the only factor influencing development of all stages, with 27°C the optimum temperature studied. Soil moisture did not influence larval development, but relative humidity affected the first five instars. Larvae required from 6 to 9 instars to complete development, with temperature and relative humidity affecting the number of molts. Head capsule measurements varied depending on the number of molts required for development. Fecundity was greatest at 27° and 20°C, and at 60% and 80% R.H. The optimum treatment for reproduction and adult survival was 20°C and 80% R.H. Many females failed to lay fertile eggs at 34° and 13°C.