Coleoborers (Curculionidae: Scolytinae) in native and homogeneous systems of Brazil nut (Bertholletia excelsa bonpl.) in the Southern Amazon, Brazil

Abstract

Brazil nut is one of the most important species of the Amazon due to its socioeconomic importance. Especially in homogeneous production systems, it may be susceptible to damage by wood-boring insects, as by the subfamily Scolytinae (Coleoptera: Curculionidae); thus, inadequate management conditions can cause economic damage. Therefore, the objective of the present work is to evaluate the occurrence of wood-boring insects (Curculionidae: Scolytinae) in native and homogeneous systems of Brazil nut in the Meridional Amazonian, Brazil. The study was conducted in three environments: Brazil Nut Native Anthropized, Homogeneous Brazil Nut and Brazil Nut Native Preserved. Twelve ethanol (96° GL) traps were installed in each environment during four sampling periods. The data were submitted to entomofaunistic analysis, Pearson´s correlation analysis and cluster analysis. A total of 2,243 individuals from 31 species were sampled, of which 23 were from the Brazil Nut Native Anthropized nut, 24 from the Homogeneous Brazil Nut and 26 from the Brazil Nut Native Preserved. Some species are restricted to a specific environment, such as Corthylocurus vernaculus Wood & Bright, 1992 and Xyleborus biconicus Eggers, 1928, in relation to Brazil Nut Native Anthropized, Xyleborus tolimanus Eggers, 1928 that occurred only in Homogeneous Brazil Nut and Corthylus antennarius Schedl and Hypothenus bolivianus Wood & Bright, 1992 verified only in Brazil Nut Native Preserved. In the faunistic analysis, we highlight the species Xyleborus affinis (Eichhoff, 1868), which was the most representative one in the three environments and a super-dominant species in all four sampling periods. Among the species considered indicator due to their high representativeness in the sampling, only Premnobius cavipennis Eichhoff, 1878 showed a significant negative correlation between its abundance and the minimum temperature for environments Homogeneous Brazil Nut and Brazil Nut Native Preserved. There was a greater similarity between the Brazil Nut Native Anthropized and the Brazil Nut Native Preserved; these two environments showed dissimilarity with the Homogeneous Brazil Nut. Monitoring wood-boring insects in Brazil nut agroecosystems is fundamental for the establishment of integrated pest management strategies.