Integration of insect sterility and insecticides for control of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Tanzania. V. The impact of sequential releases of sterilised tsetse flies

Abstract

A field trial of the sterile insect technique was conducted in Tanzania using males of Glossina morsitans morsitans Westw. that were reared, irradiated and packaged at Tanga. The experimental site was a 195-km 2 area 110 km to the south. Following two applications of endosulfan as an aerosol at an interval of 28 days, irradiated puparia of G. m. morsitans were released twice weekly at stations distributed throughout the experimental site. Each of the 120 release stations was serviced every 14 days with puparia which produced sterile adults synchronously within 30 min after placement. Over the 15-month experimental period, an average of 81 % control of G. m. morsitans was obtained, whereas G. pallidipes Aust., against which no releases were carried out, recovered to prespray levels within five months. The released sterile insects were found to be highly competitive and to survive well in the field. Immigration of indigenous flies from outside the perimeter barrier surrounding the experimental plot provided a continuous influx of fertile flies that provided the nucleus of the 19% residual population. Under operational conditions, the prevention of migration should result in the elimination of^an indigenous G. m. morsitans population subjected to the combined stress of population reduction by two applications of endosulfan aerosols and sequential releases of sterile males.

Development of a system for sterilizing tsetse flies, Glossina spp., in the Held

“…Lindquist, 1984;Politzar & Cuisance, 1984), but it involves the release of large numbers of flies into the environment in the ratio of approximately seven sterile to one wild male. In Tanzania, the release of sterile males of G.m.morsitans has great promise for control of this savannah species if reinvasion problems can be overcome (Williamson et al, 1983). However, the SIT involves great expenditure on the breeding and release of radiation sterilized flies, together with the dangers of release of large numbers of potential disease vectors (Moloo & Kutuza, 1984).…”

Combining Methods of Pest Control: Complementarity of Methods and a Guiding Principle

“…Presumably, combinations will be most effective together when they operate in very different ways with respect to pest density and do not interfere with each other. For example, the use of insecticides and sterile releases has proven successful against tsetse in spite of some degree of interference (Williamson et al [1983]; Takken et al [1986]). Part of the interference may be eliminated by judicious timing of application of the methods, for example with the insecticide-parasitoid inundation combination.…”

Mating performance of Glossina palpalis gambiensis strains from Burkina Faso, Mali, and Senegal

“…This robust technology has been successfully used in the past decades to contain, suppress, or eradicate several economically important insect pests of crops, livestock, or humans (Steiner et al, 1965;Hendrichs et al, 2002;Dyck et al, 2005). The technique was, likewise, used effectively to manage tsetse populations as was demonstrated in Burkina Faso (Politzar & Cuisance, 1984), Nigeria (Oladunmade et al, 1990), and Tanzania (Williamson et al, 1983;Vreysen et al, 2000). The application of the technology in an AW-IPM approach is complex and there are various technical and administrative prerequisites that need to be in place to be successful (Vreysen et al, 2000.…”