Control ofGlossina longipennis(Diptera: Glossinidae) by insecticide-treated targets at Galana Ranch, Kenya, and confirmation of the role ofG.longipennisas a vector of cattle trypanosomiasis

Abstract

Glossina longipennis Corti was studied in Galana Ranch, Kenya over a four year period, in two areas (Tank E and Lali) where the species was abundant and other species were absent or scarce. There was active transmission of trypanosomiasis to cattle in both areas, the parasite species being Trypanosoma vivax Ziemann and T. congolense Broden. Mean infection rates of the G. longipennis were 1.1% and 0. 55% for T. vivax and T. congolense respectively at Tank E, and 0.88% and 0.15% at Lali. Experimental transmission studies showed that cattle in fly-proof enclosures challenged with wild G. longipennis collected from Galana became infected with both trypanosome species. A tsetse control operation in one area (Tank E) using targets impregnated with deltamethrin in an oil formulation reduced the population of G. longipennis by 98% over one year, despite evidence of re-invasion. Populations of G. longipennis in the other area (Lali) were relatively stable over the whole study period. The effect of tsetse control on the incidence of cattle trypanosomiasis at Tank E was less clear than that on tsetse numbers, probably due to the lack of a sustained reduction in tsetse numbers. However, a significant relationship was demonstrated between fortnightly incidence measurements and electric net catches of G. longipennis at Tank E. A further significant predictor of incidence was rainfall in the previous four to seven weeks. This study confirms the importance of G. longipennis as a vector of bovine trypanosomiasis in areas where it is the predominant tsetse present.

Review on Epidemiology and Economic Impact of Tsetse Transmitted Bovine Trypanosomiasis in Ethiopia

“…The fusca group flies settle mainly in forests and are less important vectors of bovine trypanosomosis. Glossina longipennis and Glossina brevipalpis found in the drier areas of Kenya are exceptions among the fusca group, as they have been demonstrated to transmit trypanosomes effectively (24). In addition to tsetse flies, other hematophagous insects like tabanids and Stomoxys species also transmit trypanosomosis mechanically, as demonstrated by (25).…”

The impact of insecticide‐treated cloth targets on the survival of Stegomyia polynesiensis (= Aedes polynesiensis) under laboratory and semi‐field conditions in French Polynesia

“…Insecticide‐treated targets and traps have also proven extremely useful in the control of a variety of Glossina spp. (Diptera: Glossinidae), which are vectors for African trypanosomiasis (Leak et al ., ; Makumi et al ., ). A modification of such an approach may be an effective intervention for reducing the transmission of LF by Stegomyia mosquitoes.…”