Geographic expansion and dominance of the invading species Drosophila nasuta (Diptera, Drosophilidae) in Brazil

Biological invasions are among the main threats to biodiversity and ecosystemic services throughout the world, with the capacity for causing long-term impacts and the extinction of species. In recent decades, a growing number of invasions by insects have occurred, including flies of the family Drosophilidae. A recent case in South America is the arrival of Drosophila nasuta in Brazil. This species is native to southern Asia and has spread to Africa, islands of the Indian Ocean and Hawaii. We detected the species in the northern portion of the Atlantic Forest in Brazil, 1600 km from the closest previous record. We confirm the expansion of D. nasuta in this country using morphological and molecular genetic data for species identification. Through bi-monthly sampling in a conserved forest and on two plantations (bamboo and eucalyptus) over the course of one year, approximately 42,000 drosophilids were captured, more than 5000 of which were D. nasuta . The species was found in all sampling periods and demonstrated a preference for the conserved forest. In this environment, we detected a significantly greater abundance of D. nasuta in the dry season, which is in agreement with the seasonal pattern described for other exotic species of drosophilids in the northern portion of the Atlantic Forest. The successful invasion of D. nasuta in this portion of the biome is a serious warning sign for the Atlantic Forest, which has been largely destroyed and is one of the world hotspots for the conservation of biodiversity.