Levantamento populacional de coleópteros com armadilhas etanólicas em um sistema agroflorestal

Abstract

Beetles stand out for their potential economic damage to forest crops, making the identification and monitoring of these insects important. This study aims to collect beetles with flight interception ethanol traps in an agroforestry system of Mahogany (Swietenia macrophylla King), Australian red cedar (Toona ciliata M. Roem.) and Coffee (Coffea sp.) in Monte Carmelo, MG. For this purpose, 25 ethanolic flight intercept traps were distributed, PET-SM model, placed 1.5m above the ground, arranged every 35m apart. Six milliliters of 6º GL alcohol were used as attractant, after 15 days of exposure the material was collected. Bimonthly collections were carried out, from August 2019 to July 2020. In the laboratory, the specimens were submitted to selection, classified into morphospecies, and sent to taxonomists. From the identification of insects, the faunal analysis was performed, the spatial distribution pattern was estimated using the Morisita index. 17942 specimens of the order Coleoptera were collected, distributed in 25 families. The Curculionidae family showed greater abundance, especially the Scolytinae subfamily, with 17533 individuals, whose population acme occurred in April and July 2020, with 5943 and 6840 specimens collected, respectively. The other families totaled 409 specimens, with population acme in August 2019, when 272 specimens were collected. The Morisita index indicated aggregated spatial distribution for Scolytinae and other Coleoptera species. This pattern is explained by the fact that species of beetles feed and group together to reproduce on the host plant. This behavior is a result of the attraction to the sex pheromone, whose synthesis in males is stimulated by the feeding of the host tree. It is concluded that the spatial pattern of the Scolyte groups and other Coleoptera is aggregated, and the population peak of the species occurred in the dry-cold season of the year.