Effects of ultralow oxygen treatments at low temperature on survival of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), in blueberries and sweet cherries

Authors: Liu, Yong Biao

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/30/2025
Publication Date: 9/26/2025
Citation: Liu, Y.B. 2025. Effects of ultralow oxygen treatments at low temperature on survival of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), in blueberries and sweet cherries. Journal of Economic Entomology. https://doi.org/https://doi.org/10.1093/jee/toaf259.
DOI: https://doi.org/10.1093/jee/toaf259

Interpretive Summary: Spotted wing drosophila is a major pest of soft fruits such as blueberries, strawberries, and cherries in U.S. and is quarantined in some countries. Therefore, effective control on harvested fruits is required for export to those countries where spotted wing drosophila is quarantined. There is no effective fumigation treatment available for this pest. In this study, controlled atmosphere with ultralow oxygen (ULO) treatments at a low temperature of 3°C were studied to determine effects of combinations of ULO and low temperature on mortality of spotted wing drosophila eggs and larvae in blueberries and cherries. ULO treatments were effective against eggs and larvae of the pest. However, larvae were more susceptible than eggs to ULO treatments. ULO treatments of 72 h with 200 ppm O2 or lower achieved 100% and 95% mortalities of larvae in blueberries and cherries, respectively. The same treatments resulted in >80% mortalities of eggs in blueberries and cherries. Extension of treatments from 72 h to 96 h also increased mortality of both eggs and larvae. Low temperature also contributed significantly to mortalities of eggs and larvae. This study demonstrated that ULO treatments at low temperature has potential to be developed into an effective treatment against spotted wing drosophila in blueberries and cherries.

Technical Abstract: Controlled atmosphere with ultralow oxygen (ULO) treatments were conducted to determine effects against eggs and larvae of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), in blueberries and cherries at 3'C in 19 L cylinder chambers. For treatments against eggs, blueberries and cherries infested with spotted wing drosophila flies for 3 d were immediately subjected to ULO treatments. For treatments against larvae, blueberries and cherries which had been infested spotted wing drosophila flies for 3 d were reared at 21'C for 3 d before subjected to ULO treatments. ULO treatments of 72 h with 500, 200, and 100 ppm O2 were conducted against eggs and larvae in blueberries and cherries. ULO treatments of 96 h with 500, 200, and 50 ppm O2 were conducted against eggs in blueberries and against eggs and larvae in cherries. ULO treatments were effective against eggs and larvae of spotted wing drosophila. However, there were no significant differences among three 72-h or 96-h ULO treatments. ULO treatments were more effective against larvae than against eggs. ULO treatments of 96 h resulted in significantly higher mortality of eggs and larvae in cherries than 72-h treatments. ULO treatments of 72 h with 200 and 100 ppm O2 resulted in 100% larval mortality in blueberries and over 95% larval mortality in cherries. The same treatments yielded over 80% mortality of eggs in blueberries and cherries. All three 96-h ULO treatments resulted in over 99% mortality of larvae in cherries. The same treatments resulted in 86.05-88.41% and 89.77-94.46% egg mortalities for eggs in blueberries and cherries, respectively. This study demonstrated that ULO treatment has potential to control eggs and larvae of spotted wing drosophila in blueberries and cherries.