Observations on age-grouping the tsetse fly, Glossina pallidipes, by wing-fray and ovarian dissection, on the south Kenya coast.

Female Glossina pallidipes from biconical trap collections at five localities on the south Kenya coast were age-grouped by wing-fray and ovarian condition, and their trypanosome infection rates determined. From simultaneous application of the two age-grouping methods to 991 female tsetse, 17 reproductive age-categories were recognized. Separation into these categories was supported by a highly significant correlation between estimated age and proportion of tsetse uninfected by trypanosomes. Limitations of current age-grouping methods for tsetse are discussed.