Variação espacial e temporal na abundância de sirfídeos visitantes florais do umbuzeiro Spondias tuberosa (Anacardiaceae)

Abstract

Hoverflies (Diptera: Syrphidae) provides important ecosystem services such as biological control and pollination. The flowers visited by hoverflies usually have light coloration, accessible nectar and pollen, gathered in inflorescences, such as the flowers of Spondias tuberosa Arruda (Anacardiaceae). The aim of this study was to collect and identify hoverflies visiting S. tuberosa and analyze the abundance and dominance of individuals throughout the year in Ituiutaba, Minas Gerais, Brazil. The individuals were collected with entomological net, for three hours in the morning from 7:00 am to 10:00 am, in urban areas (A1 and A4), conservation unit (A2) and rural area (A3), from June 2020 to October 2021. The faunal index was calculated through ANAFAU program. The flowering cycle of S. tuberosa differed among the four study areas, however, the interactions with the hoverflies were higher during the rainy season, coinciding with the longer flowering periods of the umbuzeiro. A total of 345 specimens were captured, distributed in 21 morphospecies, belonging to nine genera. Area A1 had the highest abundance of hoverflies with 216 insects (62.6%), followed by A3 with 56 (16.2%), A4 with 53 (15.4%) and A2 with 20 (5.8%). Allograpta, Eristalinus, Ocyptamus and Ornidia interacted with flowers in all seasons. Allograpta was classified as superdominant, superabundant, superfrequent and constant in urban areas, while Ocyptamus indicated preference for rural areas and Toxomerus preference for forest environment. The flowers of S. tuberosa were very attractive to hoverflies, providing food resources, mainly to Allograpta in the urban environment.