Submitted to: Insect Science and Its Application
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2000
Publication Date: N/A
Interpretive Summary: Tsetse flies are vectors of a debilitating and fatal disease called Nagana in Aftican cattle, and its variant, long known in humans as sleeping sickness. A few of the many species of tsetse flies are targets for the use of the Sterile Insect Technique, in which males are released in large numbers over a sustained period of time to outcompete native fertile males for declining numbers of females, eventually eliminating the population. A scientist at the Center for Medical, Agricultural and Veterinary Entomology laboratory in Gainesville Florida was asked by the International Atomic Energy Agency to help determine whether or not tsetse flies from the laboratory colonies were potentially useful in a Sterile Male Technique large scale project. The compatability studies involved analyzing the females of each group for the presence of sexual stimulatory chemicals on the bodies of the females using a technique called gas chromatography. An Ethiopian species called Glossinapallidipes was found to be very similar to flies from other locations and the laboratory, but a different East African species, Glossina austeni, differed somewhat from northern to Southern Africa.
Technical Abstract: Wild Glossina austeni and G. pallidipes appear in many different populations. All conspecific flies possess similar surface hydrocarbons that include species-specific contact sex pheromones. Recently, evidence for a contact sex stimulant was found in the surface hydrocarbons extracted from female G. austeni. The bioactive hydrocarbon fraction contained alkanes and unsaturated hydrocarbons that were separated and analyzed by GC/G-C-MS. The structure and relative abundances of alkanes and alkenes from several populations of laboratory and wild collected specimens appeared to be similar. Similarly, the alkanes of conspecific female G. pallidipes from several locations were analyzed to determine differences and similarities with older, published work on the sex pheromone of the species. The components were analyzed by GC-MS and were very similar across populations. If major components were compared, only minor variation was observed between females from Zimbabwe (wild), Amsterdam, ICIPE/Kenya, Kenya, Tanzania (wild), Uganda/ Bristol and Arba Minch/Ethiopia. The absolute meaning of these differences are not known, since the activity of synthetic sex pheromones was shown conclusively against Wageningen and ICIPE males in 19841986 tests, although they were less active against Zimbabwe males.