Diversidade de abelhas (Hymenoptera: Apoidea) em paisagens agrícolas e florestais em região de Mata Atlântica, sul de Minas Gerais, Brasil

Abstract

Bees are the insects responsible for providing one of the most important ecosystem services on our planet: pollination. However, habitat fragmentation due to the expansion of agricultural practices and urbanization is identified as the main cause of the decline of bee populations in the worldwide. Therefore, the goal of this research was to evaluate the responses of bees to a mosaic of agricultural and forest landscapes, highlighting the diversity, composition and seasonality of these insects in an Atlantic Forest region in southern Minas Gerais, Brazil. The study was carried out in different types of habitats, being two forest (remnant of native forest and regenerating forest) and three agricultural (apple, olive and peach tree), all located in the municipality of Maria da Fé, in the Experimental Field of the Agricultural Research Company of Minas Gerais for 12 months (November 2017 to October 2018). Three sampling sites were installed in each habitat, and in each site three aromatic traps were installed, each with a different essence (eugenol, methyl salicylate and vanillin). The traps remained in the sites for 15 days of each month, with a sample being carried out per month for a year, totaling 4.320 hours of sampling per habitat (15 days x 24 hours x 12 months = 4.320 hours). Regarding orchid bees (Euglossina) a total of 1.416 specimens were collected, belonging to four genera and 10 species. The greatest abundance of bees was recorded in the forest remnant with 791 specimens, followed by the apple tree with 203 specimens and the olive tree with 171 specimens. The species Eufriesea violacea was the most abundant in the five habitat types, comprising 64.05% (n = 907) of the specimens collected, followed by Euglossa truncata with 18.57% (n = 263) and Eulema nigrita with 13.77% (n = 195). The highest species richness was observed in peach tree (9 spp.), followed by the forest remnant (8 spp.), regenerating forest and olive tree (both with 7 spp.) and apple tree (6 spp.). Among the other species of wild bees (non-euglossina), 946 specimens belonging to 18 genera and 33 species were collected. The greatest abundance was recorded in peach tree with 426 specimens, followed by apple tree with 250 specimens and olive tree with 214 specimens. Bombus brasiliensis, Scaptotrigona bipunctata and Trigona spinipes were the only species captured in the five habitats. The apple tree was the habitat that showed the largest number of bee species, recording 22 species, followed by the olive tree and the peach tree, which recorded 17 species each. The species T. spinipes was the most abundant in three types of habitats, representing a relative abundance of 85.68% (n = 426) in the peach tree, 73.83% (n = 214) in the olive tree and 67.60% (n = 250) in the apple tree, while B. brasiliensis was the most abundant species in the regenerating fragment and in the remaining native forest, with relative abundance of 30.76% (n = 8) and 40.00% (n = 12), respectively. It is concluded that the mosaic of adjacent agricultural and forest habitats can favor the floral visits of bees in different environments, in addition to facilitating the reintegration of the community of these insects in anthropized habitats (agricultural crops), in addition, the proximity between the types of habitats (forest and agriculture) seems to favor the visitation rate of bees in agricultural crops. Keywords: Native bees. Abundance. Richness. Nat