Comparison of Gut Contents of Adult Diabrotica virgifera Le Conte and Diabrotica Longicornis (Say) (Coleoptera: Chrysomelidae)

The western corn rootworm Diabrotica virgifera Le Conte and Diabrotica Longicornis (Say) (Coleoptera: Chrysomelidae) are two of the most serious pests of corn in Nebraska and other states. Though they are serious pests, much is yet unknown about their biology and ecology. The present study was undertaken to determine if apparent differences in feeding behavior are real and if other differences not suggested by observation exist. Beetles were collected during 1971 from four corn fields, preserved, dissected and the contents of a portion of the gut of each beetle examined and identified by comparison with a reference slide set of known and possible beetle foods. Percentages of beetles eating specific foods or groups of foods were tested using Chi-square. Tests in 1972 of larger samples of beetles were made between species collected from corn and/or weeds, between sexes within species collected from corn and/or weeds and within species collected from corn vs. weeds. Advisor: Roscoe E. Hil