The biological quality of sterile male insects produced in a mass-rearing facility is a prerequisite for the success of the SIT, which is a component of area-wide integrated pest management (AW-IPM). Indeed, sterile male insects released in the field must have a good mating performance in order to compete with wild males, but they must also present the required level of sterility. In the present study, the biological quality of sterile male Glossina palpalis gambiensis produced in a mass-rearing insectary was assessed through quality control testing. The mating performance of irradiated males was assessed in walk-in field cages. Irradiation had no effect on adult emergence but significantly reduced the percentage of operational flies (from 89.58% to 79.87%) and male survival (from 5 to 4 days, on average). However, irradiation did not impact the sterile male insemination potential, with all females inseminated and more than 80% of the spermathecae completely filled. The rate of induced sterility in females was 89.67% due to a dose rate decrease of the radiation source. Moreover, sterile males were able to compete successfully with untreated fertile males for untreated females in walk-in field cages. This study confirmed that the flies were still competitive and stressed the importance of regularly checking the radiation source parameters.

Background The main challenge to the successful mass-rearing of the tsetse fly in insectaries, especially in Africa, is a sustainable supply of high-quality blood meals. As such, the collection of high-quality blood in large quantities can be an important constraint to production. One possible strategy to lessen the impact of this constraint is to modify the blood-feeding frequency. In the study reported here, we evaluated the effect of three blood-feeding frequencies on the colony performance of Glossina palpalis gambiensis, a riverine tsetse fly species. Methods The effect of three, four and six blood-feedings per week on female survival and productivity were evaluated over a 30-day period. Progeny emergence rate and flight ability were also evaluated. Results Female survival was significantly higher in flies fed four times per week (87%) than in those fed three (72%) and six times per week (78%; P < 0.05). Productivity was similar between flies fed four and six times per week (457 and 454 larvae) but significantly reduced in flies fed three times per week (280 larvae produced; P < 0.05). Both emergence rate and flight ability rate were also similar between flies fed four times per week (97 and 94%, respectively) and six times per week (96 and 97%, respectively), but they were significantly reduced when flies were fed three times per week (89 and 84%, respectively; P < 0.05). Conclusions Blood-feeding frequency could be reduced from six times per week to four times per week without affecting mass-rearing production and progeny quality. The implications of these results on tsetse mass-rearing production are discussed.

Background: In tsetse fly mass-rearing insectaries, the sustainable supply of high quality blood meals is the main challenge, especially in Africa. Because the collection of high quality blood in large quantities may be an important constraint to production, blood feeding frequency can be a lever to lessen its impact. Therefore, this study evaluates three blood feeding frequencies on Glossina palpalis gambiensis colony performance.Methods: Three effects of blood feeding treatments - three, four and six times per week - were evaluated on female survival and productivity over a 30-day period. Progeny emergence rate and flight ability were also evaluated.Results: Female survival was significantly higher for flies fed four times per week (87%) than three (72%) and six times (78%; p<0.05). Productivity was similar between flies fed four and six times per week (457 and 454 larvae) but significantly reduced when fed three times (280 larvae produced; p<0.05). Similarly, emergence rate and flight ability rate were both similar between flies fed four times (97% and 94%) and six times (96% and 97%) per week but significantly reduced when fed three times per week (89% and 84%, respectively; p<0.05).Conclusions: Blood feeding frequency could be reduced to four times per week without affecting mass-rearing production and progeny quality. We discuss the implications of these results on tsetse mass-rearing production.