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Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/6/2005 Publication Date: 11/28/2005 Citation: Sappington, T.W. 2005. First-flight adult European corn borer (Lepidoptera: Crambidae) distribution in roadside vegetation relative to cropping patterns and corn phenology. Environmental Entomology. 34:1541-1548. Interpretive Summary: The European corn borer, Ostrinia nubilalis (Hübner), is a serious pest of corn throughout much of the U.S. east of the Rocky Mountains. The adults are moths that live for about 10 days and congregate in grassy areas like road ditches where they rest during the day. At night, the females fly into cornfields to lay their eggs. We sampled moths by disturbing the grass with a 5-foot garden stake in a series of ditches in central Iowa in 2003 and 2004, counting the number of moths that flew out. We found that the moths are not randomly distributed among ditches in the landscape, but are concentrated near corn. The moths overwinter as full grown caterpillars in corn debris on the surface of the soil, but evidence from this study indicates that they do not stay in grass near the field they emerge in. This information on moth dispersal behavior is important to scientists who are designing programs to delay development of resistance in this insect to Bt-corn, and for planning strategies to stop the spread of resistance should it develop. Technical Abstract: The European corn borer, Ostrinia nubilalis (Hübner), is a serious pest of commercial maize throughout the U.S. Corn Belt. Adults aggregate in grassy areas around and within the cornfield where they spend the daylight hours resting, and where mating activity occurs at night. Mated females leave the aggregation sites at night to oviposit in cornfields, thus using the grass as a staging area. Flush samples were taken in borrow ditches in central Iowa during the first (spring) flight of moths in 2003 and 2004 to determine if cropping patterns and crop phenology influence moth distribution across the landscape. Significantly more moths were present in ditches with an adjacent cornfield on at least one side of the road than in those with no corn on either side. In contrast, effects of corn stubble from the previous year's crop, tillage, and corn phenology were weak or not detectable. Evidence suggests that some moths emerging from corn stubble may aggregate in adjacent grass, but that they redistribute themselves in the landscape within a short time. Thus, the presence or absence of adjacent corn was the overwhelming factor affecting spatial distribution of first-flight European corn borer moths among grassy ditches. |
