The Influence of Yeast Hydrolysate on the Behavior of the Melon Fly1

This study, which was conducted to determine some effects of yeast hydrolysate on the behavior of the melon fly (Dacus cucurbitae Coq.) in the field, showed that the number of flies present or found dead was greater when yeast hydrolysate bait was applied to non-host plants favored by the adults than to favored host plants or to plyboard slabs. The application of yeast hydrolysate to non-host plants, fuzzy rattle pod (Crotolaria incana L.) and corn, did not result in an increase of flies on the treated plants in certain tests, but in others there was an increase. In general, positive responses were found to be associated with high population density. The application of this bait to host plants, cucumber and cantaloupe, did not result in the movement of flies to these crop plants from nearby untreated corn plants.