Glossina or tsetse flies, the vectors of sleeping sickness, form a unique group of insects with remarkable characteristics. They are viviparous with a slow rhythm of reproduction (one larva approximately every 10 days) determined by the regular ovulation of alternate ovaries. This unusual physiology enables the age of the females to be estimated by examining the ovaries.The resulting ovarian age structure of tsetse fly populations has been used to develop research into the demography of tsetse flies. Several authors have (...) proposed methods of estimating population growth rates from ovarian age distribution data. However, such methods are applicable only when the growth rate () is equal to 1 (i.e. the intrinsic rate of increase r is equal to 0). In fact, in this type of estimation, the adult survival rate a (or equivalently the mortality rate) cannot be dissociated from the growth rate. (shrink)

Odor baited methods of controlling tsetse have received considerable attention as ecologically friendly ways for African farmers to reduce their levels of livestock trypanosomosis. Over the last decade, a number of tsetse control projects have been set up in East Africa using these methods. Although much has been written, few hard data are available regarding their ongoing success, problems, and sustainability. To evaluate the situation on the ground, the authors conducted a series of site visits to a number of such (...) tsetse control projects in Kenya. A comparison of these projects with others across the region identified the possible constraints to a wider uptake of these methods. Poor information, coupled with inappropriate research and development policies, were found to be the key constraints. These could be overcome with a farmer-based approach to control, with a better application of existing techniques, and with a greater role for veterinarians. Tsetse control needs to become demand rather than supply driven, if it is to bean important component of livestock disease control in Africa. (shrink)