Effects of floral nectar on longevity and nutrient levels of Drosophila suzukii

Adult feeding can be an important component of an insect’s life history.  Many Diptera at the adult stage are dependent upon feeding to enhance biological parameters such as longevity and egg production.  Through the consumption of sugar meals, energy for metabolic purposes can be generated immediately or stored for later use by converting monosaccharaides to trehalose or glycogen, occasionally lipids if lipogenesis is present in the insect species. 

For our study, an economically important invasive fly, Drosophila suzukii, was provided with blueberry blossoms to determine if blossom presence enhanced D. suzukii’s longevity under controlled conditions mimicking Willamette Valley mid-spring periods.  A second feeding study was conducted on D. suzukiito determine nutrient levels after a 24 and 48-hour feeding period on fruit blossoms, sucrose, or water.  We subsequently compared the levels of glycogen, lipids, fructose, and non-fructose sugars post feeding using anthrone and vanillin bioassays.  Exposure to blossoms enhanced longevity and resulted in higher levels of glycogen, fructose, and non-fructose sugars.  Lipid levels were not improved.

Implications of this study are that D. suzukii survival and nutrient levels may be enhanced with the field presence of nectar sources as is typically found during spring season in this production region.  This knowledge may direct possible future management tactics of this important pest.