Spatial Distribution of the Migrants of the Corn Delphacid, Peregrinus maidis (Ashmead) (Homoptera: Delphacidae) in Cornfields

Abstract

Spatial distribution of the migrants of the corn delphacid in plantings of corn used for silage was determined by sampling population density at sites throughout fields. By this means, migrants were found to aggregate along borders of fields. There were variations to this pattern, but the same borders were generally infested in successive plantings of the same field. Within each field, population density decreased continuously with distance from the borders. This decline was shown to be described by the relationship log(m) = log(a)+bx, where m is the average number of migrants per plant at distance, x (in meters), from the edge, and a is the average per plant at the field edge. Calculation of b, the regression coefficient, and use of this information in pest surveillance are described.