Ambrosia and bark beetles (Scolytidae : Coleoptera) in pine and eucalypt stands in southern Brazil

More than 95% of the reforested area in Brazil is covered by exotic Eucalyp tus and Pinus plantations. Native Scolytidae, mostly ambrosia beetles, appe ar to be rapidly adapting to these exotic trees, and reports of economic da mage are becoming frequent. The objectives of our research were to survey, characterize and compare the Scolytidae fauna present in a P. taeda and an E. grandis stand in Telemaco Borba, Parana state, Brazil. Beetles were caug ht in ethanol baited ESALQ-84 vane traps in weekly collections from July 19 95 until July 1997. In all, 87 species were trapped, 62 in the pine and 75 in the eucalypt stand. The most abundant beetle species in the pines were H ypothenemus eruditus, Xyleborinus gracilis, Cryptocarenus sp. and Xylosandr us retusus, while the most frequent were H. eruditus, Cryptocarenus sp., H. obscurus, Ambrosiodmus obliquus, and X. gracilis. In the eucalypt stand, H . eruditus, X. retusus, H. obscurus, X. ferrugineus and Microcorthylus mini mus were the most abundant species, and H. eruditus, H. obscurus and M. min imus were the most frequently trapped. The majority of the species, regardl ess of the forest community, were most active between August (end of winter ) and October (mid-spring). Significantly more H. eruditus, X. gracilis, Cr yptocarenus sp., Corthylus obliquus, Hypothenemus bolivianus, A. obliquus, Sampsonius dampfi and Xyleborus affinis were trapped in the pine stand, whi le X. retusus, H. obscurus, X. ferrugineus, Xyleborinus linearicollis, Cort hylus sp, and Corthylus convexicauda were caught in higher numbers in the e ucalypt stand. Approximately 50% of the species trapped were found in both communities. Morisita's similarity index indicates the composition of the t wo communities is very similar, suggesting that most of the beetles are pol yphagous. (C) 2001 Elsevier Science B.V. All rights reserved.