Synergistic and additive interactions among components of food-based baits underlie female fruit fly attraction

Authors: PINERO, JAIME - University Of Massachusetts, Amherst; Souder, Steven; VARGAS, ROGER - Former ARS Employee

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: The Mediterranean fruit fly, Ceratitis capitata, oriental fruit fly, Bactrocera dorsalis, and melon fly, B. cucurbitae are serious insect pests threatening agriculture worldwide. Monitoring and control of fruit flies around the globe have relied on the application of food-based baits. This tactic targets both male and female fruit flies with the latter being slightly higher in percentage. The tactic is based on their need for sugar and protein which is required for development, survival, and egg production in female flies. Key to the development of attractive lures and baits is the determination of the types of interactions existing among bait components. This study conducted with the Agricultural Research Service (ARS), U.S. Department of Agriculture, Daniel K. Inouye Pacific Basin Agricultural Research Center, Hilo, Hawaii, aimed at establishing the attractiveness of a protein-rich material (trub), protein deficient material (Concord grape juice), and attractant ammonium acetate evaluated singly, to females of three fruit fly species (B. cucurbitae, B. dorsalis, and C. capitata). We also sought to elucidate the type of interactions existing between ammonium acetate vs. Concord grape juice and trub. The results from the present study (1)established a significant attraction of B. cucurbitae, B. dorsalis, and C. capitata females to trub, grape juice, and ammonium acetate when tested singly, and (2) revealed the existence of synergistic interactions among bait components for B. cucurbitae and B. dorsalis, whereas for C. capitata additive effects were noted for all evaluations. These results increase our understanding of female B. cucurbitae, B. dorsalis, and C. capitata foraging behavior in response to protein-rich (trub) and protein deficient (grape juice) materials, and the specific ways these low- and high-attractiveness materials interact with ammonium acetate. The contribution of ammonium acetate in fruit fly attraction should be greater for comparatively low attractiveness materials and should be less relevant for comparatively high-attractiveness materials. Our findings improve the understanding and efficacy of semiochemicals used for integrated pest management of fruit flies, and the development of low-cost technologies for stakeholders and farmers when commercially produced baits are expensive or unavailable.

Technical Abstract: Attraction of tephritid fruit flies to some food sources can be enhanced by the presence of ammonia derivatives, compounds that are perceived as volatile cues for protein-rich food sources. Using a comparative approach, we (1) evaluated the behavioral responses of females of three invasive fruit fly species, Bactrocera (Zeugodacus) cucurbitae (Coquillett), Bactrocera dorsalis (Hendel), and Ceratitis capitata (Wiedemann) (all Diptera: Tephritidae) to trub (a protein-rich waste brewer’s yeast product generated during the production of beer), Concord grape juice (a protein-deficient material), and ammonium acetate, and (2) identified synergistic and additive interactions between low- and high attractiveness materials and ammonium acetate. We established the attractiveness of fresh trub, grape juice, and ammonium acetate when tested singly to females of all three fly species. Although ammonium acetate did not enhance significantly the response of females of any species to fresh trub, the most attractive material, ammonium acetate, did significantly enhance females’ level of response to aged trub (a comparatively less attractive material) and to grape juice. Our research found a synergistic interaction between diluted grape juice and ammonium acetate for B. cucurbitae, as well as between aged trub and ammonium acetate for B. dorsalis. For C. capitata, additive effects among food attractants and ammonium acetate were identified. Our findings increase our understanding of fruit fly female olfactory-driven behavior in response to food-based materials and the extent to which ammonium acetatemodulates female response to protein-rich and protein-deficient materials.