Indian meal moth survivability in stored corn with different levels of broken kernels

Survivability of Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), larvae fed a standard laboratory diet and whole corn with 0, 5 to 7, and 100% broken corn kernels, was assessed under laboratory conditions at 28°C, 65% relative humidity, and 14:10 h (L:D) photoperiod. A conventional yellow dent corn hybrid (about 3.9% oil content, dry basis) and a high-oil corn hybrid (about 7.7% oil content, dry basis) were tested. Survivability was measured as the percentage of pre-pupae, pupae, and adults observed at the end of the rearing period. For the standard laboratory diet, a mean of 97.5% larvae survived. Percentage of larval survival increased as the percentage of broken corn increased. Mean percentages of larval survival for the conventional yellow dent corn were 6.7, 63.8, and 80.0 for 0, 7, and 100% broken kernels, respectively. The mean percentages of larval survival for the high-oil corn hybrid were 28.3, 81.3, and 100.0 for 0, 5, and 100% broken kernels, respectively. Larval growth rate for high-oil corn was faster than for conventional corn. Results indicate that cleaning corn before storage could reduce P. interpunctella problems.