Composição de moscas varejeiras (Diptera: Calliphoridae e Mesembrinellidae) em fragmento urbano de Floresta Atlântica e área urbana na Zona da Mata, Juiz de Fora, Minas Gerais, Brasil

Abstract

The Atlantic Forest is one of the priority areas for biodiversity conservation and it suffers from the high levels of anthropogenic disturbances, leaving only 12.4% of its original cover remaining. Thus, urban areas containing this biome gain importance for conservation and dipterans play an important role as bioindicators. This study aimed to analyze the fauna of blowflies in a forest environment and urban area and to evaluate the usefulness of this information in the monitoring of environmental preservation area in an urban fragment of Atlantic Forest in Juiz de Fora, Minas Gerais, Brazil. The collections were carried out monthly from May 2015 to April 2017 in the Botanic Garden (JB) and the Universidade Federal de Juiz de Fora (UFJF). The traps were kept for four days in the field, surveyed daily and the flies collected. In total, 25.731 blowflies were collected, with JB presenting greater species richness, abundance, and diversity, but with dominance and equitability with values lower than UFJF. Chrysomya albiceps was the most abundant species (n = 9.229) and dominant in both environments, followed by Hemilucilia segmentaria, Lucilia eximia, and H. semidiaphana. Mesembrinella bellardiana showed a significant preference for the most preserved environment, as indicated by its greater abundance in JB (n = 1.215) in relation to UFJF (n = 43). The dissimilarity of composition was observed between JB and UFJF, even the two localities sharing 85.71% of the species collected. For both locations, the highest abundance was observed in the spring and the lowest in the autumn, and in relation to the seasons, the rainfall presented the highest values when compared to the dry season. The blowflies tended to be more abundant with the increase in the day of exposure of the attractive baits present in the traps, and this correlation was positive and extremely strong, with the fourth day showing the highest abundances. The proportion of females was higher than that of males in both places. With regard to environmental variables, only UFJF presented a significant correlation between the general abundance of the fly and the average temperature. The presence of synanthropic species in both localities is a reflection of the anthropic influence and, as JB is surrounded by urban area it ends up being influenced by the human presence, whose impact reflects in greater abundance of these species in this environment. H. segmentaria e H. semidiaphana are characteristics of forested areas and were abundant in both collection sites, showing that, for the UFJF, the small forest fragments serve as an environment for the installation of these species. The presence of synanthropic and asynanthropic species in non-characteristic environments demonstrates the ability of these dipterous to seek different areas for occupation due to anthropic action. The record of M. bellardiana and Laneella nigripes in JB indicates the preservation of this site, emphasizing the importance of the conservation of this fragment that is susceptible to strong anthropic pressure and urban expansion. The fact that M. bellardiana was collected in very low abundance in the UFJF shows its repulsion to this clearly anthropic environment. This is the first study on the composition of blowflies in the Atlantic Rainforest biome in the state of Minas Gerais.