Composição e estrutura das comunidades de staphylinidae (coleoptera) em agroecossistemas e ecossistemas naturais no nordeste paraense

Abstract

The soil fauna and leaf litter, has high diversity and rapid reproductive capacity, are excellent bioindicators, and its properties or functions indicate and determine the quality or level of soil degradation. The Rove beetle (Coleptera: Staphylinidae) can be used as bioindicators of degraded areas, contributing to a proper environmental assessment, in addition to contributing to the ecological processes. The aim of this study was to analyze and compare the composition and structure of the Rove beetle communities in natural ecosystems and agroecosystems in the municipality of Igarapé-Açu-PA. This study took place September 2014 through April 2017. Seven ecosystems, two natural ecosystems and five agroecosystems, different in size and fauna and flora composition, were determined for the development of the research. For sampling insects using pitfall traps (Pitfall) consisting of plastic cups with 8 cm diameter and 14 cm high, with a volume of 500 mL, containing 1/3 of the volume with a solution consisting of water and 1% formaldehyde plus a few drops of detergent neutral, to kill and keep the insects. Sampling occurred every two weeks and from 2016 were monthly. The specimens collected were sent to the laboratory for sorting, assembling and labelling of beetles. The indices obtained Morisita similarity and Sorensen, Simpson's dominance and Berger-Parker, Menhinick richness and Margalaf, Shannon diversity and Fisher's alpha and Pielou evenness and Buzas and Gibson, through software PAST 3.16. During the sample period, 885 Rove beetle specimens collected from five subfamilies. It was largest Rove beetle abundance in orange tree area (L) with 488 specimens, followed by pasture area (P) with 137 and forest area (M) with 96. The agroecosystem areas were more similar, especially citrus and corn area (A). Analyses of diversity (Shannon and Fisher alpha) showed the area M as more diverse; on the other hand the capoeira area (C) showed the lowest rate of diversity. Aleocharinae (S = 20 and N = 643), Scydmaedinae (S = 8 and N = 160), Staphylininae (S = 6 and N = 46), Paederinae (S = 6 and N = 20) and Euasthetinae with only one representative, were the subfamilies that occurred during the collection period. It was noted that in every instance Aleocharinae had ecosystems, especially in the L with 422 individuals. The high similarity and dominance among the agricultural systems suggest the habit of these opportunistic beetles, while the high diversity in natural systems provides better structure in the community of Rove beetle.