Attraction of fruit flies of the genus Bactrocera to colored mimics of host fruit

Abstract

In tests on feral populations of polyphagous Bactrocera tryoni (Froggatt) adults on host guava trees, both sexes were significantly more attracted to Tangletrap-coated 50 mm diameter spheres colored blue or white than to similar spheres colored red, orange, yellow, green, or black or to Tangletrap-coated 50 mm diameter yellow-green guava fruit. In contrast, in tests on feral populations of oligophagous Bactrocera cacuminata (Hering) on host wild tobacco plants, both sexes were significantly more attracted to Tangletrap-coated 15 mm diameter spheres colored orange or yellow than to other colors of spheres or to Tangletrap-coated 15 mm diameter green wild tobacco fruit. Both sexes of both tephritid species were significantly more attracted to blue (in the case of B. tryoni) or orange (in the case of B. cacuminata) 50 mm spheres displayed singly than to blue or orange 15 mm spheres displayed in clusters, even though fruit of wild tobacco plants are borne in clusters. Finally, B. tryoni adults were significantly less attracted to non-ultraviolet reflecting bluish fruit-mimicking spheres than to bluish fruit-mimicking spheres having a slightly enhanced level of ultraviolet reflectance, similar to the reflectance of possible native host fruit of B. tryoni, whose bluish skin color is overlayed with ultraviolet-reflecting waxy bloom. Responses to fruit visual stimuli found here are discussed relative to responses found in other tephritid species.