The flower flies and the unknown diversity of Drosophilidae (Diptera): a biodiversity inventory in the Brazilian fauna

Abstract

Diptera is a megadiverse order, reaching its peak of diversity in Neotropics, although our knowledge of dipteran fauna of this region is grossly deficient. This applies even for the most studied families, as Drosophilidae. Despite its position of evidence, most aspects of the biology of these insects are still poorly understood, especially those linked to natural communities. Field studies on drosophilids are highly biased to fruit-breeders species. Flower-breeding drosophilids, however, are worldwide distributed, especially in tropical regions, although being mostly neglected. The present paper shows results of a biodiversity inventory of flower-breeding drosophilids carried out in several localities in Brazil, based on samples of 125 plant species, from 47 families. Drosophilids were found in flowers of 56 plant species, from 18 families. The fauna discovered showed to be highly unknown, comprising 28 species, 12 of them (>40%) still undescribed. Not taking in account opportunist species, two thirds of the diversity exclusive from flowers were undescribed. The Drosophila bromeliae species group was the most representative taxon, with eight species (six undescribed), including four polyphagous and four Solanum-specialised species. This specialisation on Solanum is reported for the first time for Drosophila. Other taxa of restrict flower-breeding drosophilids were the Drosophila lutzii species group and the genus Zygothrica. Some specimens of the genera Cladochaeta, Rhinoleucophenga and Scaptomyza were found, but their relations to flowers are unclear. Additionally, ten species of ample niche was found using flowers opportunistically. Localities and host plants are recorded for all species collected.