University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Urban Spitaler
(2016):
Influence of dietary yeasts on the fecundity and oviposition of adult spotted-wing drosophila (Drosophila suzukii; Diptera: Drosophilidae).
Master / Diploma Thesis - Abteilung Pflanzenschutz,
BOKU-Universität für Bodenkultur,
pp 75.
UB BOKU
obvsg
FullText
- Abstract:
- The spotted-wing drosophila (Drosophila suzukii), native to Asia and widespread throughout North America, South America and Europe, is an invasive insect pest. The tendency of D. suzukii to lay eggs in healthy ripe fruits makes it an important insect pest for soft and stone fruits. Several studies document the attractiveness of yeast volatiles to D. suzukii adults and the important role of yeasts in the diet of D. suzukii larvae, suggesting that D. suzukii adults are also affected by the yeast community in their diet. Under optimal laboratory conditions (22 °C, 76.4% relative humidity and a photoperiod of 16:8 (L:D) h) the effects of four yeast species, Saccharomyces cerevisiae, Metschnikowia pulcherrima, Candida sp. and Hanseniaspora uvarum, in the diet of a South Tyrol ecotype of D. suzukii adults were observed. In addition to the tested yeast cultures, two other feeding and oviposition substrates were offered. The cage design was invented for this study, and the construction steps are described in detail. Among the yeast species known to be associated with D. suzukii, the ones used in this study turned out to increase the number of eggs laid compared to the yeast-less control, suggesting that yeast in the diet is beneficial but not essential for D. suzukii adults. Significantly more eggs were laid by females fed with S. cerevisiae and H. uvarum compared to females fed with Candida sp. The number of eggs laid, the survivorship, and egg laying behaviors of D. suzukii adults were observed simultaneously for each yeast species offered. D. suzukii females showed a significantly shorter lifetime when fed with yeast species that lead to higher fecundity. Survivorship of D. suzukii males showed no significant influences by the yeast diet offered. In the present study, D. suzukii female flies showed no oviposition preference for yeast cultures on malt extract agar. The possible reasons for the observed behaviors are discussed in the thesis.
- Beurteilende(r): Koschier Elisabeth Helene