Mating Competitiveness ofBactrocera dorsalis(Diptera: Tephritidae) Males From a Genetic Sexing Strain: Effects of Overflooding Ratio and Released Females

Abstract

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a global pest that infests a range of fruit and vegetables. Males are attracted to methyl eugenol, and control is often achieved by the Male Annihilation Technique, where methyl eugenol + insecticide dispensers are deployed to eliminate males, preclude matings, and reduce population growth. The Sterile Insect Technique (SIT) has also been used to control B. dorsalis. The SIT involves the release of mass-reared, sterilized males to achieve matings with wild females, who then produce inviable eggs. Two key elements of SIT include the overflooding ratio achieved (sterile: wild males) and the strain type utilized, namely bisexual or genetically sexed (allowing male-only releases). Here, we describe the effects of these two factors on the mating competitiveness of a males from a genetic sexing strain of B. dorsalis, termed DTWP. Mating success was scored for DTWP versus wild males in field cages at ratios of 1:2, 1:1, 2:1, and 10:1 both when DTWP females were or were not concurrently released with DTWP males. Close correspondence was found between observed numbers of matings of particular male–female combinations and expected numbers based on the numbers of flies released of each sex and each strain. As a result, the proportion of total matings achieved by the DTWP across the eight treatments showed a corresponding increase with overflooding ratio. At a given ratio, DTWP males had a higher relative mating success when DTWP females were absent rather than present, although the reason for this was unclear.

Age‐dependent effect of methyl eugenol on male mating success of the peach fruit fly, Bactrocera zonata

“…Sexual maturity age in some Bactrocera wild flies has been reported as 2–3 weeks (Wee & Tan, 2000; Wee et al, 2018). Laboratory colonization is reported to shorten the precocious duration (Wong et al, 1989; McInnis et al, 2004; Haq et al, 2010; Shelly, 2020; Shelly & Manoukis, 2022). In the present study, 8 days of age was recorded as the male mating initiation age in both laboratory and field cage experiments.…”

Effect of X-ray irradiation on the biological parameters of Xestia c-nigrum

“…The advantage of the sterile insect technique (SIT) is that it is specific to the target pest and its action is based on releasing males that confer sterility to females that the males seek out and mate with. This mode of action makes SIT particularly effective at controlling hidden pests, especially those whose larvae burrow or live in the soil ( Shelly and Manoukis, 2022 ; Chen et al, 2023 ). For example, the release of sterile Cydia pomonella male moths in the Similkameen Valley of British Columbia in Canada from 1976 to 1978 resulted in 100% reduction of economic damage in orchards ( Proverbs et al, 1982 ).…”