Dispersal ofNezara viridula1andPiezodorus guildinii1Nymphs in Soybeans

Abstract

Dispersal of Nezara viridula (L.) and Piezodorus guildinii (Westwood) nymphs, the 2 most abundant stink bugs in soybeans in Brazil, was studied. Results showed that they moved more along than across rows. Maximum distance recorded for both species along rows was 12 m, while across rows was 7.2 m for N. viridula and 4.8 m for P. guildinii . The total number of nymphs recaptured was higher for P. guildinii than N. viridula , and the recovery rate decreased with increase in distance from the release point. Nymphs in the 2nd and 3rd stages showed strong gregarism and dispersal was more pronounced for 4th and 5th stages, which were the principal ages involved in colonization of the field. Dispersal patterns of the nymphs best fitted the equation Y = a + b Log x + c/x, where Y = density, x = distance from the release point, a = intercept, b = slope, and c = a proportionality constant.