• melon fly;
  • methoprene;
  • protein diet;
  • sterile insect technique


Enhanced male melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) mating success due to application of a juvenile hormone analogue, methoprene (M+) and feeding on a sugar–protein diet (P+) (hydrolysed yeast), supports their incorporation into operational area-wide programmes integrating the sterile insect technique. But enhanced mating success may have a cost in terms of shortened sterile male longevity as has been reported under certain situations for other tephritid pest species. The objective of this study was to analyse the effect of methoprene treatment and addition of protein to the adult diet and then switching from a sugar–protein diet to sugar only (dietary switched after first 3 days; DS), on male longevity in laboratory. The treatments were as follows: (i) M-P+; (ii) M-P+ DS; (iii) M+P+ DS; and (iv) M-P- (fed only sugar and water continuously since emergence). All treatments were significantly different from each other in their survival response in the following order, M-P+ > M+P+ DS > M-P+ DS > M-P-. Access to sugar–protein diet and then switching after 3 days had no negative effect on male longevity compared with males fed only sugar throughout. The results are discussed in the context of methoprene treatment and a sugar–protein diet as a pre-release feeding protocol for maturing sterile flies in fly emergence/release facilities.