Some Environmental Factors Affecting Feeding, Oviposition, and Survival of the Southern Corn Rootworm12

Abstract

The effect of food, light, humidity, and temperature on feeding, oviposition, and survival of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, was studied under controlled laboratory conditions. Adult rootworms preferred to feed in the light on lettuce and sliced yellow squash and they preferred to oviposit in the shade or dark on moist cotton in preference to candidate legumes or curcubits. Larvae did not reject any food offered in a forced-feeding (isolation) test, but they preferred sliced yellow squash when given a choice. Humidity has a significant effect on adult survival, oviposition, and egg hatch. A relative humidity above 75% was established as essential. Adult survival, oviposition and longevity were studied at 5 temperatures ranging from 45 to 95°F. Longevity was best at 65°F, and 95°F was detrimental after 3 days’ exposure. Few eggs were deposited at 45°F, large numbers were deposited at all test temperatures above 65°F, and oviposition was optimum at 85°F