Two volatiles from anthracnose-infected blueberries trigger electrophysiological and aversive behavioral responses in Drosophila suzukii (Diptera: Drosophilidae)

Authors: QUADREL, AMANDA - Rutgers University; FERGUSON, BETH - Rutgers University; Rering, Caitlin; URBANEJA-BERNAT, PABLO - Institute Of Agrifood Research And Technology; RODRIGUEZ-SAONA, CESAR - Rutgers University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2025
Publication Date: 2/19/2025
Citation: Quadrel, A., Ferguson, B., Rering, C.C., Urbaneja-Bernat, P., Rodriguez-Saona, C. 2025. Two volatiles from anthracnose-infected blueberries trigger electrophysiological and aversive behavioral responses in Drosophila suzukii (Diptera: Drosophilidae). Journal of Economic Entomology. toaf032. https://doi.org/10.1093/jee/toaf032.
DOI: https://doi.org/10.1093/jee/toaf032

Interpretive Summary: The fruit fly spotted wing Drosophila (Drosophila suzukii) is the most destructive pest of small fruits in the USA and around the world. The life cycle of D. suzukii make them difficult and expensive to control with insecticide sprays. As an alternative or supplement to pesticides, repellent odors can be used to manipulate pest behavior in the field, diverting pests away from a crop. ARS Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL in collaboration with scientists from Rutgers University tested the repellent odors for their ability to reduce D. suzukii infestation of blueberry fruit and found certain odors reduced infestation of fruit in semi field tests. This study provides more field-relevant evidence that these odors can be incorporated into effective management strategies. An effective repellent of D. suzukii would help reduce physical and economic damage incurred by this agricultural insect pest.

Technical Abstract: Native to Southeast Asia, the spotted-wing drosophila (Drosophila suzukii Matsumura), is an economically important invasive pest of thin-skinned fruits such as raspberries, blueberries, and strawberries worldwide. To reduce the reliance on insecticides for managing this pest, alternative strategies like behavioral manipulation are needed. Previous studies have shown that adult D. suzukii avoid blueberries infected with the fungal pathogen Colletotrichum fioriniae Marcelino & Gouli, which causes anthracnose fruit rot, leading to the identification of nine potential repellent compounds. In this study, we further investigated the two most potent of these compounds—ethyl butanoate and ethyl (E)-but-2-enoate—to assess their repellent properties on the antennal and behavioral responses of D. suzukii. Electroantennogram (EAG) assays revealed that both esters elicited dose-dependent responses in male and female D. suzukii, often stronger than those triggered by 2-pentylfuran, a known D. suzukii repellent. Additionally, we examined the behavioral responses of adult D. suzukii to these three repellent compounds under semi-field and field conditions using cages containing potted and planted blueberry bushes, respectively. Results from cage studies showed that ethyl butanoate, ethyl (E)-but-2-enoate, and 2-pentylfuran significantly reduce D. suzukii oviposition and adult emergence from blueberry fruits, with ethyl (E)-but-2-enoate sometimes outperforming the other compounds. These findings indicate that both esters–ethyl butanoate and ethyl (E)-but-2-enoate, induced by C. fioriniae-infected blueberries–have dose-dependent effects on D. suzukii antennae and act as effective oviposition deterrents, supporting their potential as promising tools for managing this pest through behavioral strategies.