Date of Award
Doctor of Philosophy
Richard L. Hellmich
Leslie C. Lewis
Popcorn was evaluated for its potential as a refuge for European corn borer, Ostrinia nubilalis (Hubner) and the corn rootworm complex, which includes western, Diabrotica virgifera virgifera LeConte, and northern, Diabrotica barberi Smith and Lawrence, corn rootworms. The first objectives of these studies were to determine if more larvae were produced in popcorn than in field corn and to determine how popcorn influenced female oviposition and larval distribution within neighboring field corn. Two varieties of popcorn (M140, 105d and M3374Y, 118d), one mixture of popcorn (50% 105d and 50% 118d), and field corn (DK580, 108d) were evaluated. Significantly higher densities of O. nubilalis larvae were found in popcorn than field corn. Moth oviposition and larval distribution were evaluated using 105d popcorn embedded in several cornfields across Iowa. Significantly more egg masses and larvae were found in the popcorn compared with field corn. One or two rows of field corn adjacent to popcorn tended to have higher numbers of egg masses and larvae compared with background field corn. Number of eggs per egg mass was significantly higher in popcorn than field corn. These data suggests more O. nubilalis are produced in popcorn than field corn. Popcorn has no effect on O. nubilalis egg mass and larval distribution after 1.5m. The second objective was to determine if popcorn can influence corn rootworm distribution. Two varieties of popcorn (105-d and 118-d), one mixture of popcorn (50%: 105-d and 118-d), and field corn (108-d) were evaluated. Significantly higher numbers of western and northern corn rootworm adults were captured from popcorn plots in 2000 and 2002. Adult corn rootworm captures were not significantly different from popcorn and field-corn plots during 2001. The third and fourth objectives were to determine if total corn rootworm beetle emergence and the rate of beetle emergence were similar from 20 plots of popcorn and field corn with various treatment combinations. Emergence rates and total beetle emergence from popcorn plots tended to be lower than from field-corn plots. These data suggests popcorn influences adult corn rootworm distribution, however, compared to field corn, popcorn produces fewer beetles.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu
Colothdian Deavonder Tate
Tate, Colothdian Deavonder, "Evaluating popcorn as potential refuge for European corn borer (Ostrinia nubilalis) and corn rootworm beetles (Diabrotica spp) " (2004). Retrospective Theses and Dissertations. 819.