Effects of Precipitation and Wind on Populations of Adult European Corn Borer (Lepidoptera: Pyralidae)1

Abstract

Adult European com borer (ECB), Ostrinia nubilalis (Hubner), populations were monitored with three different sampling methods (blacklight trap, dropnet, flush bar) during flights 1 and 2, 1980–1981. There was evidence that rainstorms (1.28 to 2.50 cm) accompanied by moderately violent (30 to 40 km/h) and violent winds (65 to 80 km/h) destroyed much of the aggregated ECB adult populations in a grassy area (action site) during flight 1, 1980. Relatively light precipitation (ca. 0.25 cm) with mild winds (0 to 15 km/h) occurred for periods during the second flight of ECB, 1980, and during the first flight of ECB, 1981. Light (0.03 to 0.25 cm), moderate (0.26 to 1.02 cm), and heavy rains (1.03 to 2.50 cm) fell throughout flight 2, 1981, but were not accompanied by violent winds. During this flight, based on sample data from all three methods, the adult population levels in four action sites were not affected by the rain. We conclude that adult ECB population levels may not be reduced by precipitation alone. But when precipitation is accompanied by violent winds, adult ECB population levels can be greatly reduced.