Migratory Aphid (Hemiptera: Aphididae) Habitat Selection in Agricultural and Adjacent Natural Habitats.

Paired suction traps were used to study the habitat choice of migrating aphids in adjacent crop and natural habitats in east central Illinois. Traps were placed in a row-crop field and a restored prairie for 4 yr at one site, and a row-crop field and a wooded plot for 3 yr at another. Row crops were corn or soybean, rotated annually. We did not wish to sample aphids that were native to the local habitats because they would be in a habitat by circumstance of birth, and not necessarily by choice. We therefore removed from the habitat choice analysis any aphid species that colonize plants in either the agricultural or natural habitat. Numbers of aphids from outside sources in the two adjacent habitats were compared. In 2 of 4 yr, outside-source aphids were more abundant in the row-crop than the restored prairie, despite the absence of potential host plants in both habitats. In all 3 yr, outside-source aphids were trapped in greater numbers in the crop than in the woods. Selection of the crop over the natural habitat occurred during almost all sampling periods throughout the summers. We present possible explanations for the aphids' apparent preference for crop habitats and provide brief discussions of abundant aphids, local--as well as outside--source species, trapped in our study. We also discuss the relevance of our study to the understanding of long- and short-distance aphid migration and aphid vectoring of plant pathogens. [ABSTRACT FROM AUTHOR]