ENVIRONMENTAL HETEROGENEITY AS A STRATEGY FOR PEST-MANAGEMENT IN EUCALYPTUS PLANTATIONS

The effect of environmental heterogeneity on the distribution and abun dance of Lepidoptera was tested in Eucalyptus plantations interwoven w ith natural vegetation. Collections were carried out in Aracruz, ES, B razil, in five sites along a 1000 m transect starting in a native wood land and penetrating stands of Eucalyptus grandis and Eucalyptus salig na. Collections were undertaken with light traps, three times a month, from April to August, 1993, recording the number of individuals per m orphospecies in each site. A positive correlation was found between th e number of sites where each species was recorded and its mean local a bundance (r(2) = 0.45; P<0.01; n = 790), indicating that the more ubiq uitous Lepidoptera species are also those that were locally more abund ant. No pest species was recorded among those very abundant. Pest spec ies generally presented moderate abundances and only three out of ten were found at all sites. Tt seems, therefore, that pest species were c onstrained by the heterogeneity conferred by the coexistence of Eucaly ptus plantations and remnants of native vegetation. (C) 1998 Elsevier Science B.V.