Choice response of the olive fruit fly, Bactrocera oleae, to various bait/insecticide combinations: hydrolyzed proteins or ammonium salts?

Abstract

Key to the success of the ground bait spray application method (‘attract and kill’) against Bactrocera oleae is to effectively suppress its population by inducing good levels of attraction and stimulate flies to ingest a lethal dose of the toxicant. A 2-year long field bioassay (fly captures to sticky panels) was developed to evaluate the exposure and response of olive flies to hydrolyzed protein based and ammonium salt baits in combination with various insecticides. A significantly higher attractive response of fruit flies was recorded in the case of the protein Entomella/phosmet combinations among protein bait/combination. Though next year, an enhanced attractive effect and a longer residual activity of ammonium salts compared to the tested protein to the olive fruit fly was clearly demonstrated. Especially in the case of beta-cyfluthrin mixed with ammonium salts, the mean number of captured flies were at least 3 to 11-fold (depending on the salt) higher compared to the respective protein-containing mixture baits instead of the organophosphate phosmet. Ammonium salts can successfully replace proteins in bait sprays.