Showing papers by "Marc J. B. Vreysen published in 1999"
TL;DR: While effective control of G. austeni using blue cotton screens was shown to be feasible, it required a high deployment density and a long intervention period, and females were more influenced by the screens than males.
Abstract: A tsetse-control trial was carried out in a primary forest habitat on Unguja Island of Zanzibar to assess the effect of insecticide-impregnated blue cotton screens on a population of Glossinn austeni Newstead. In November 1991, screens were deployed at densities of 45–70 per km2 and the fly population was monitored monthly using sticky panels. Both female and male daily catches were not affected during the initial five months after screen deployment, but the physiological age distribution of female flies shifted significantly towards younger groups. Females were more influenced by the screens than males. The fly population was very low after the long rainy season, but increased to pre-control levels three months after the flooding of the forest floor. Thereafter, male and female apparent densities decreased, and 78–91% and 98–99% suppression was obtained for males and females respectively at the end of the 18-month intervention period. While effective control of G. austeni using blue cotton screens was shown to be feasible, it required a high deployment density and a long intervention period.
7 citations
TL;DR: Studies were made of Glossina austeni captured with sticky panels during the dry and wet season in the northern and central part of the Jozani forest on the island of Unguja, Zanzibar to assess the stability of the fly population in terms of density and composition.
Abstract: Studies were made of Glossina austeni captured with sticky panels during the dry and wet season in the northern and central part of the Jozani forest on the island of Unguja, Zanzibar. The density of the fly population was significantly higher in the northern part of the forest than in the central. Female and male daily catches remained stable in time in the northern part of the forest but the density of the male fly population declined significantly in the central part of the forest at the end of the dry season. The magnitude of the catch and the sex ratio of the samples was highly affected by the trap site in both locations. Only samples in the central part of the forest were biased towards one of the sexes depending on the seasons. The age composition of the male flies was independent of locality and season but the one of female flies was influenced by the seasons in the central part of the forest. The breeding and abortion rate of flies were similar in the two locations both during the wet and dry seasons. The stability of the fly population in terms of density and composition is probably a reflection of the optimal environmental conditions in this primary forest habitat.
2 citations