Mating competitiveness of the adult oriental fruit fly reared as larvae in liquid vs. those raised on standard wheat-based diets
Three strains (standard laboratory, dorsalis translocation white pupae (DTWP) pupal colour sexing strain and wild strain) of adult oriental fruit flies, which were reared as larvae on liquid diet (LD), mill-feed diet (MF) (Tanaka’s diet) or natural host fruit diet, were evaluated for mating competitiveness in both indoor and outdoor Boller’s mating cages and outdoor field cages. The Relative Sterility Index (RSI) was used as an indicator of mating capability. The RSI between standard strain adults that grew as larvae in LD and those in Tanaka’s MF indicated no statistically significant difference in Boller’s mating cage results after irradiation and dye marking. These results show that irradiation and dye marking had no effect on laboratory mating ability. Adults of the DTWP genetic sexing strain based on pupal colour that were reared as larvae in a LD (DTWP-LD) or MF (DTWP-MF) had a lower mating ability than the standard laboratory strain in Boller’s cages, and against the wild strain in both Boller’s and field cages. However, there was no statistically significant difference between irradiated DTWP-LD strains in competition with non-irradiated standard laboratory strain or DTWP-MF strain in Boller’s cages. These findings indicate that (i) the quality of the DTWP sexing strain may be less capable in mating than the standard laboratory and wild strains and (ii) LD reared larvae can produce adults of equal mating ability compared with adults reared on a conventional diet. LD reared fruit flies should therefore be ready for mass scale rearing for Sterile Insect Technique programmes following the completion of other field quality control tests, including those measuring dispersal abilities.
Document Type: Research Article
Publication date: December 1, 2008