Efeitos da poluição e do desmatamento sobre as comunidades de gerromopha e nepomorpha (insecta: heteroptera) nos igarapés do município de manaus, amazonas.

Abstract

There are few studies on Gerromorpha and Nepomorpha (Insecta: Heteroptera) with emphasis on anthropogenic impact. The aim objective of this present study work is to know the taxonomic composition, the diversity and the distribution of aquatic and semiaquatic heteropteran faunagoal in amazonian streams of pristine forested areas under none or minimal human interference and urban streams, together with water quality of these streams. The sampling was carried out from March, 2004 to August, 2005 in 30 streams in Reserva Florestal Adolpho Ducke (a forest reserve near Manaus, AM) and 37 streams in the city of Manaus. It was collected an amount of 2.927 especimens, distributed in 12 families, 28 genera, 30 morphotypes and 52 species of Gerromorpha and Nepomorpha. In this material, there are some exemplars not yet identified, and possible represent undescribed species. Cannonical Corresponence Analysis (CCA) and Multiple Regressions were performed and showed close relationships between heteropteran species and some envoronmental variables, indicating a positive association of some taxa and pristine environments, with higher values of current velocty in streams, higher values of dissolved oxygen, higher values of Habitat Integrity Index (HII) and lower values of total Nitrogen. Some species also were indicators to hidrologic periods and to mesohabitats. These results indicate that surveys on aquatic and semiaquatic heteropterans in human impacted areas might be usefull as aditional tools in evaluation of water quality of human impacted streams.