Behavioural and electrophysiological response of Anastrepha fraterculus (Diptera: Tephritidae) to a -lactone synthetic semiochemical.

GOANE, L.; CARRIZO, B.; RUIZ, M. J.; BACHMANN, G.; MILLA, F.; SEGURA, D.F.; KUZMICH, D.; WALSE, S.; VERA, M.T.

Insects

MDPI

Lugar: Basel; Año: 2023

2075-4450

Attractants are a powerful tool for pest management. The lack of specific attractants for the South American fruit fly, Anastrepha fraterculus, a complex of cryptic species of great economic im-portance in South America, makes it difficult to monitor the pest in the field. The -lactone male sex and aggregation pheromones of several Anastrepha species, naturally released in a 7:3 epianastrephin to anastrephin ratio, and a structurally related naturally occurring -lactone ((±)-trans-tetrahydroactinidiolide) with gem-dimethyl groups (dimethyl) at C(4), were evaluated as potential attractant of this species. Different age and mating status of A. fraterculus males and females were evaluated during electroantennography (EAG) and field cage experiments in which polymeric lures were deployed to contain 100 mg of attractant. Epianastrephin and dime-thyl were EAG+ for all fly conditions; with epianastrephin eliciting the highest response for both sexes; and immature flies showing greater responsiveness than mature ones. In the field cage experiments, immature flies were only attracted to leks; virgin females were attracted to leks, dimethyl and both epianastrephin-anastrephin formulations (95 and 70 wt.% epianastrephin); mature-mated males were attracted to leks, dimethyl and 70 wt.% epianastrephin; and ma-ture-mated females were only attracted to leks. Our bioassays showed a promising performance of the analog dimethyl since it elicited the same response as epianastrephin, requires less steps to synthesize and contains one less chiral center than the natural pheromones. The attraction to leks was recorded for all mating status and ages of flies and suggests that air-borne volatiles of calling males contain cues which could be acting as a sensory trap. The addition of any of these compounds in the synthetic attractants may result in a greater attraction and thus deserves fur-ther evaluation. Dose response experiments will provide additional information to move a step forward and validate the results obtained in open field conditions.