Comparative dispersal and survival of male oriental fruit flies (Diptera: Tephritidae) from wild and genetic sexing strains

Abstract

The Sterile Insect Technique (SIT) is a target-specific, biologically based method used to control invading or established populations of pestiferous tephritids. SIT entails the release of large numbers of mass-reared, sterilized males, with the goal of achieving sterile male x wild female matings, which yield infertile eggs and suppress the growth rate of the pest population. The development of male-only strains generates the potential for more effective control of invading populations than standard bisexual releases. A genetic sexing strain based on sex-linked pupal color exists for Bactrocera dorsalis (Hendel), a major agricultural pest worldwide, but how this strain might perform in an SIT program has not been thoroughly investigated. As documented for several tephritid species, artificial selection imposed via mass-rearing may have adverse effects on various biological parameters of the released flies, including dispersion, life span, and mating competitiveness. The objective of the present study was to directly compare lure responsiveness using methyl eugenol, dispersal, and survival between males from wild and genetic sexing strains (GSS) of B. dorsalis. We conclude that males of the two strains differed significantly in dispersal ability but not in lure attraction or survival ability. The prospective effectiveness of the GSS in SIT programs against B. dorsalis is evaluated based on these findings.