Diversidade de espécies de Syrphidae (Diptera) em duas fitofisionomias em área de transição Cerrado-Mata Atlântica no sul de Minas Gerais

Abstract

One of the relevant issues in studies of ecology is the loss of biological diversity, in which aiming to find solutions that reduce this impact, one of the proposals is the elaboration of biological surveys in areas of preservation and conservation for their management. Among the steps to manage preservation studies, it is essential to carry out biological inventories before any decision is taken. Syrphid flies are considered good indicators of the integrity of the environment, as they perform various ecological services such as pollination, biological control and decomposition. However, Syrphidae is still among the least studied Diptera families in the Neotropical Region, a fact that is due to the few specialists in the family, added to the great diversity and the number of species. The present study was carried out in order to investigate and compare the abundance and diversity of adult hoverflies in two areas of environmental preservation over two years and verify the influence of precipitation and temperature on the abundance, richness and composition of Syrphidae species in stage adult. Sampling was carried out between October 2018 and August 2020, using two types of sampling techniques: flight interception trap and active search in the Brazilian Cerrado and Atlantic Forest areas in the Biological Reserve Unilavras - Boqueirão – RBUB, Ingaí, Minas Gerais State, Brazil. A total of 442 individuals from 66 species of Syrphidae were collected. The most abundant genus was Toxomerus containing the 2 most abundant species, Toxomerus lacrymosus (Bigot, 1884) and Toxomerus laenas (Walker, 1852). The Brazilian Cerrado area showed the highest number of individuals, while the Atlantic Forest area showed the highest richness. The rarefaction, interpolation and extrapolation curves revealed that the number of species grows exponentially according to the increase in the number of samples. For the composition of the community, the analysis showed that T. lacrymosus (Bigot, 1884) and Salpingogaster nigra Schiner, 1868 are relevant species in the community, being present in both localities; however the first was more abundant for the Cerrado area while the second for the Forest area. The collection site and temperature had significant effects on the community. Richness was not significantly affected by any variable, while abundance, collection site, temperature and type of trap were significant. For diversity, only the collection site had a significant effect. Therefore, it is concluded that the temperature influences the abundance of Syrphidae, demonstrating that high temperatures negatively affect the quantity of specimens to be collected; the Forest area has a higher diversity index than the Cerrado area, which validates the importance of conserving the environment for the preservation of all species present there.