Formulation of pyriproxyfen, a juvenile hormone mimic, for tsetse control.

. A topical dose, in 1 uJ acetone, of 0.02 |xg 2-[l-methyl-2-(4-phenoxyphenoxy) ethoxy] pyridine, the juvenile hormone mimic pyriproxyfen (S-31183, Sumitomo Chemical Co.), caused an adult female tsetse, Glossina morsitans morsitans Westwood, to produce non-viable offspring for the whole of her life. Using 14C labelled pyriproxyfen it was determined that as little as 0.001 fig transferred to the in utero larva was sufficient to arrest development in the pupal stage. A formulation in vegetable oil was prepared for treating black cotton cloth targets which caused females to pick up 0.1 p-g active ingredient (a.i.) by tarsal contact during 1 min of exposure. Males exposed similarly for between 1 and 5 min transferred up to 0.016 |xg a.i. to females if they mated immediately after treatment. Doses as low as 0.01 |xg in 10 |JL1 oil cnT2 on black cotton cloth targets caused females to produce non-viable offspring for at least two reproductive cycles following exposure. However, a dose of 0.1 u-g in 10 |xl oil cm-2 was necessary for an exposed male to cause disruption of the reproductive potential of his mate. This juvenile hormone mimic has potential to induce sterility via both sexes of tsetse using treated targets or traps under field conditions.