INFLUENCES OF TEMPERATURE AND MOISTURE ON HATCHING OF EGGS OF THE PALE WESTERN CUTWORM, AGROTIS ORTHOGONIA MORR. (LEPIDOPTERA: NOCTUIDAE)

Abstract

Laboratory studies showed that hatching of fully developed eggs of the pale western cutworm varied directly with temperature and relative humidity, that prolonged exposure to temperatures from −5° to −15 °C. did not affect ultimate hatch, and that desiccation, particularly in the range 20° to 30 °C., caused considerable embryo mortality. Studies outdoors showed that 45 to 60 days were required in the fall to complete embryonic development and that most of the hatching occurred in the early spring. Findings in the laboratory, corroborated by studies outdoors, showed that eggs are admirably adapted to develop, withstand climatic factors, and hatch at a time when their survival is ensured.