Field Guide to Venomous and Medically Important Invertebrates ...

Figure 197. Adult black fly (Simulium sp.). Photo: Kansas State University
Tsetse flies (Family Glossinidae)
Tsetse flies, genus Glossina, are vectors of African sleeping sickness (African trypanosomiasis),
and they can pose a significant threat to military members deploying to central Africa. Tsetse
flies can be readily distinguished from other biting flies occurring in Africa by their long
proboscis which projects forward approximately one-half the length of the body. Adult female
tsetse flies do not lay eggs, but they carry a single larva in their abdomen. This fully developed
larva is ―larviposited‖ prior to pupation where it borrows into loose soil or sand.
Adult tsetse flies use visual cues to find their victims so bites are exclusively during daylight.
Avoidance and proper wear of the uniform are the best means of avoiding tsetse fly bites.
Tsetse flies are difficult to control because they are often distributed over large geographic areas
and the adults are highly mobile. While it is possible to achieve eradication of tsetse in particular
areas, such attempts usually fail in the long run because of immigration of tsetse-flies from other
areas. Although several means of controlling these insects have been developed, only a few are
applicable for use by deployed military personnel. The main control methods for local areas
include remove brush and trees to eliminate shaded areas where lariposition occurs. However,
this method is labor intensive, and it may not be practical during a military operation. Use of
residual insecticides on resting areas, and application of non-residual aerosols to kill adult tsetse
can be effective, but such applications must be repeated at regular intervals in order to kill newly
emerged adults. Both ground and aerial application methods have been used with success in
Africa. Trapping adult tsetse flies using a biconical trap or similar methods can be especially