|Abraham, John - NON ARS EMPLOYEE|
|Angeli, Sergio - NON ARS EMPLOYEE|
|Rodriquez-saona, Cesar - RUTGERS UNIVERSITY|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2015
Publication Date: 3/16/2015
Citation: Abraham, J., Zhang, A., Abubeker, S.U., Angeli, S., Rodriquez-Saona, C. 2015. Behavioral and antennal responses of spotted wing drosophila, drosophila suzukii, to volatiles from fruit extracts. Environmental Entomology. 44(2):356-367.
Interpretive Summary: The spotted wing drosophila (SWD) is an invasive species native to Southeast Asia. It has become a serious pest of soft-skinned fruit crops since its introduction into North America and Europe. SWD damage to small fruit crops, such as raspberry, blueberry, cherry, and strawberry, results in significant financial losses to farmers. Due to the economic impact of SWD on fruit crops, farmers usually resort to frequent applications of insecticides. Early detection of this fly on farms is essential for quick management measures that could lead to reductions in the rate and amount of insecticide applications. However, the current SWD population monitoring tool is not selective, catching many other non target insects. More importantly, it cannot detect SWD prior to fruit injury for timely interventions. To improve the lures currently used to monitor SWD and identify fruit-based chemicals, we investigated the attraction of SWD to volatiles from four of its highly preferred hosts: blueberry, cherry, raspberry, and strawberry and found that some volatile compounds are attractive to SWD. Synthetic version of identified chemicals was evaluated in the laboratory condition and the behavioral activity was confirmed. Our discovery provided natural product-based alternative lure and will help scientists and farmers to develop improved SWD population monitoring and infestation detection tools, thereby helping growers apply insecticide in a timely manner. In addition, identification of the fruit-based attractant will also enable further development of attract-and-kill technology for managing SWD populations below economic injury levels.
Technical Abstract: Native to Southeast Asia, the spotted wing drosophila, Drosophila suzukii, has become a serious pest of soft-skinned fruit crops since its introduction into North America and Europe in 2008. Current monitoring strategies use baits based on fermentation products; however, to date, no fruit-based volatile blends attractive to this fly have been identified–this is particularly important because females seek ripening fruit for oviposition. Thus, we conducted studies to: a) investigate the behavioral and electroantennographic (EAG) responses of adult D. suzukii to volatiles from blueberry, cherry, raspberry, and strawberry fruit extracts; b) identify the antennally-active compounds from a highly attractive extract (raspberry) using gas chromatography-mass spectrometry (GC-MS) and coupled GC electroantennographic detection (GC-EAD); and, c) test a synthetic lure containing the EAG active compounds identified from the raspberry extract on adult attraction. Volatiles from all four fruit extracts were attractive to female and male D. suzukii in olfactometer studies and elicited strong EAG responses, with responses ranked as: raspberry = strawberry > blueberry = cherry. Principal component and GC analyses showed that the fruit extracts emit distinct volatile profiles. In GC-EAD experiments, 11 volatiles from the raspberry extract consistently elicited antennal responses in D. suzukii. In choice test bioassays, a synthetic lure containing the EAG-active blend in mineral oil attracted '3 times more D. suzukii than control (mineral oil alone) lures. To our knowledge this is the first report of a behaviorally and antennally-active blend of host-fruit volatiles attractive to D. suzukii, which offers promising opportunities for the development of improved monitoring tools.