FIELD TRIALS WITH THE SYNTHETIC PYRETHROIDS PERMETHRIN, CYPERMETHRIN AND DECAMETHRIN AGAINST GLOSSINA (DIPTERA, GLOSSINIDAE) IN NIGERIA

Two years of field trials in Nigeria with the synthetic pyrethroids permethrin, cypermethrin and decamethrin against Glossina palpalis (R.-D.) and G. tachinoides Westw. are described. Laboratory tests were also made against G. morsitans submorsitans Newst. The three pyrethroids were applied successfully from the ground at 0·5%, 0·3% and 0·075%, respectively, to fly resting sites on vegetation using pressurised knapsack sprayers, populations of both species being eradicated after a single application of one insecticide. Following residual spraying from a helicopter, only decamethrin at 30 g/ha achieved complete eradication. It was thought that, with permethrin wettable powder at 200 g/ha, by modifying the spraying equipment and, with cypermethrin, by increasing the dosage to over 150 g/ha, both could be successful in the future. A new ‘sideways’ spraying technique tested using the helicopter gave promising results. Comparatively little harm was done to non-target organisms in the environment after spraying with any of the three pyrethroids, and it is expected that they may gradually replace the chlorinated hydrocarbons in future routine anti-tsetse operations. © 1979, Cambridge University Press. All rights reserved.