Two Triflumuron Application Methods on Glossina palpalis gambiensis in the Laboratory: Impact on Female Fertility

Abstract

The objective of this study was to compare the efficacy of two triflumuron-application methods on male tsetse flies to achieve transfer of the product to the females during subsequent mating. For the topical application, which consisted in applying the solution to the upper part of the thorax, four groups of six-day-old male tsetse flies received 1 μg, 2 μg, 5 μg triflumuron in 1 μl water, and water only for the control group, respectively. Each male group was mated consecutively with three groups of 150 three-day-old females. The effects assessed were the abortion rate, eclosion rate, and shape and weight of pupa. The analysis of the results of the first four reproductive cycles of the females showed significant differences between the eclosion rates in females mated with males treated at the doses of 2 μg and 5 μg, and eclosion rates in females mated with the control group only during the 1^st cycle of the 1^st mating (p < 0.05). The second method consisted in spraying 200 males with an 0.8 ml solution containing 3% triflumuron, i.e. less than 1 μg triflumuron per fly. Treated males and the control group were then exposed to three groups of females as described above. The results showed not only highly significant differences during the four reproductive cycles of the 1^st mating, but also during the 2^nd mating in the means of eclosion rates (p < 0.001). During the 1^st mating the mean of eclosion rates of the first four reproductive cycles was 43.7 ± 22% in the treated group vs 89.0 ± 0.5% in the control. The transfer of triflumuron (5 μg/fly) to females by males treated with the topic method was little effective compared to that obtained with the spraying method.