Levantamento, diversidade e sazonalidade de curculionidae: Scolytinae, Platypodinae e Bostrichidae associados a habitat naturais e cultivados no estado do Tocantins

Abstract

Coleoptera borers participate in the process of wood decomposition in nature and are potentially harmful in forest environments, whether natural or cultivated. In view of this, the objective of the work was to assess the occurrence, diversity, register faunal indices and population fluctuation of Coleoptera (Curculionidae: Scolytinae, Platypodinae and Bostrichidae) in natural environments of the Tocantins cerrado, monocultures of exotic forest species and fruit crops and Agroforestry System (SAF), in the period from January 2017 to April 2018, as well as develop and test a new impact trap model in 2016. Three ethanol-fired impact traps were used per habitat studied, with fortnightly collections. The new trap model, called the Bionorte impact trap, showed efficiency in the collection of Scolytinae, obtaining greater diversity and scope of capture when ethanol was used as an attraction, with no statistically significant difference between the floral attractions tested. Xyleborus spp. had a polyphagous habit and was captured in all treatments, with Hypothenemus spp. being more abundant. The evaluation of coleoptera borers in the nine environments studied, Scolytinae showed predominance in all habitats, Platypodinae was classified as predominant only in the cerrado habitat with predominance of babassu in the floristic composition, while Bostrichidae was predominant only in the cultivation of açaí. Eucalyptus cultivation had the highest Shannon-Wiener Diversity Indices (H’= 0.8016) and Equitability (E= 0.7297) with the lowest indices (H'= 0.1653) and (E= 0.1504) in mango cultivation. When the fragment of cerrado, teak and rubber plantations were analyzed, 2700 individuals were collected, distributed in 57 species, being Scolytinae the most diversified with 35 (61.40%) species collected and the most abundant with 2232 (82.70%) individuals collected. Sorensen’s similarity quotients revealed values of 80.65% similarity between taxons caught in the savannah fragment and rubber tree culture. In the fauna analysis X. picea and C. diadematus occurred as predominant in all sampled environments.