Oviposition performance of Drosophila suzukii females across different yeast species

Abstract: Yeasts are known to play an important role in nutrition physiology and host attraction of many Drosophila species. Among other saprophagous Drosophila species, Drosophila melanogaster Meigen shows high attraction to Saccharomyces cerevisiae for oviposition. Predominant associations of yeasts to Drosophila suzukii were detected to be similar on different cultivated host plants. In our study we observed the egg-laying behaviour of spotted-wing drosophila on fruits artificially associated with various yeast species. To record oviposition behaviour on a natural substrate, ripe cherry fruits were inoculated with selected yeast species. The behaviour of two populations of D. suzukii females, one population maintained in the laboratory for several generations on artificial diet and another population obtained from infested cherry fruits and reared for one generation in the laboratory on cherry fruits, was studied in this experimental trail. To allow sexual maturing and egg production and to detect posteclosional nutrition influences, the respective yeast species were provided as the only protein source to adult flies between eclosion and experimental start. The comparison of the selected yeast species shows significantly highest number of eggs from females of both populations when fed with Candida sp. on inoculated cherry fruits. Additionally high numbers of eggs were detected on S. cerevisiae for the wild population. Possible reasons for this behavioural distinction between the selected yeast species are discussed with focus on nutritional quality and odour mediated attraction.