The biochemical adaptations of spotted wing drosophila (Diptera: Drosophilidae) to fresh fruits reduced fructose concentrations and glutathione-S transferase activities

Authors: NGUYEN, PHUONG - Hallym University; KIM, A-YOUNG - Hallym University; JUNG, JIN KYO - National Institute Of Crop Science - Korea; Donahue, Kelly; JUNG, CHULEUI - Andong National University; Choi, Man-Yeon; KOH, YOUNG HO - Hallym University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2016
Publication Date: 2/25/2016
Citation: Nguyen, P., Kim, A., Jung, J., Donahue, K.M., Jung, C., Choi, M.Y., Koh, Y. 2016. The biochemical adaptations of spotted wing drosophila (Diptera: Drosophilidae) to fresh fruits reduced fructose concentrations and glutathione-S transferase activities. Journal of Economic Entomology. 109(2):973-981. doi: 10.1093/jee/tow019.

Interpretive Summary: Spotted wing drosophila (SWD), Drosophila suzukii, is a severe invasive pest attacking a wide range a wide range of small fruits including almost all cherry cultivars. In the genus Drosophila SWD has unique evolutionally ecological and morphological adaptations. The most important ecological adaptation is the host shift with its food preferences from rotten to fresh ripening soft skin fruits. SWD exhibits a broad range of almost all varieties of small fruits including blackberries, blueberries, cherries, peaches, raspberries, strawberries, and grapes. Since the first outbreak in California 2008 the distribution of SWD is rapidly expanding across the U.S., Canada and Europe. The estimated economic impact from crop yield loss, drop in market value, and higher management cost is hundreds of millions of dollars in the U.S. alone, and increasing every year. To replace or reduce the use of chemical insecticides, currently alternative options are being developed, but there are still many critical gaps to be implemented against SWD in field. Scientists from USDA-ARS at Corvallis, OR and Gainesville, FL, Hallym University, Andong University, and National Institute of Crop Science from South Korea studied SWD geographical populations, and studied biological and biochemical characters to compare to D. melanogaster. Also identified the physiological and metabolic basis of SWD related in food preferences to healthy ripening fruits. This finding is why SWD more prefer and attracted to ripening fruits rather than rotten fruits compared to D. melanogaster which more like to decay fruits. The research results provide our fundamental questions from SWD specific food preference and tools to develop SWD management.

Technical Abstract: Spotted wing drosophila (SWD), Drosophila suzukii, is an invasive and economically damaging pest in Europe and North America, because the females have a serrated ovipositor enabling them to infest ripening almost all small fruits before harvest. Also flies are strongly attracted to fresh fruits rather than rotten foods compared other Drosophila species. To understand the physiological and metabolic basis of SWD food preferences to healthy ripening fruits, we investigated SWD geographical populations, and studied biological and biochemical characters to compare to D. melanogaster. In US populations, Hawaii and Oregon are not close each other and slightly different, but their similarity seems to mixed with Korean populations. We found that the susceptibility to oxidative stressors was significantly increased in D. suzukii compared to D. melanogaster. Also, SWD had significantly reduced Glutathione-S transferase activities and gene numbers. In addition, the fructose concentration found in SWD was significantly lower than D. melanogaster. Those results strongly suggest that the altered food preferences of SWD could be from evolutionally adaptation of fresh food by the alteration of carbohydrate metabolisms and GST activities.