Effect of broken corn on indianmeal moth survivability

Survivability of Indianmeal moth, Plodia interpunctella (Hübner), larvae fed a standard laboratory diet, whole corn with 0% broken kernels, whole corn with 5 to 7% broken kernels, and 100% broken corn kernels were assessed in our laboratory at 28°C, 65% RH, and 14 h light :10 h dark photoperiod cycle. A conventional low-oil yellow dent com (about 3.9% oil content) and a highoil com hybrid (about 7.7% oil content) were tested. Survivability was measured as the percentage emergence of pre-pupae, pupae, and adults at the end of the rearing period. For the standard laboratory diet, a mean ± SD of 97.5% ±2.9 larvae survived. The mean ± SD percentages of larval survival for the conventional low-oil yellow dent corn were 6.7 ± 2.9, 63.8 ± 4.8, and 80.0 ± 14.7 for 0, 7, and 100% broken kernels, respectively. The mean ± SD percentages of larval survival for the highoil corn hybrid were 28.3 ± 12.6, 81.3 ± 4.8, and 100.0 ± 0.0 for 0, 5, and 100% broken kernels, respectively. Larval growth rate for high-oil corn was faster than for low-oil corn. Results indicate that cleaning corn before storage could reduce lndianmeal moth problems. Also, Indianmeal moth problems in high-oil corn varieties might be slightly greater than in corn varieties with normal oil levels.