金沢大学留学生センター室内および野外個体の解剖観察をもとに, S. ochraceumの羽化から吸血までの最短期間を2日, 吸血から産卵までを5日, 産卵後まもなく2回目の吸血をすると仮定すると, 吸血-産卵-吸血(gonotrophic cycle)の最短期間は5日と考えられた。調査4地点(1977年10月∿12月)の平均産卵経験率はS. ochraceum 48.7%, S. callidum 46.9%, S. metallicum 41.2%, S. mexicanum 38.9%であった。産卵経験率およびsac-like relic率は日変化を示し, 午後に高い傾向を示した。以上のことからS. ochraceumの日生存率は0.866と計算され, 羽化後1回目の吸血でO. volvulusのMf.を取り込んだとして, これが感染型に発育し, 伝播可能になる吸血後9日目の生存率は27.3%と推定された。 Of the S. ochraceum in Guatemala, the shortest duration from emergence to blood-feeding, from blood-feeding to oviposition (both at 22℃) and from oviposition to next blood-feeding (under the field condition) were presumed to be 2 days, 5 days and 0 day, respectively. One gonotrophic cycle of this species was to be 5 days in the shortest case. The average parous rate observed in the blackflies collected at four locations from October to December, 1977 were 48.7% for S. ochraceum, 41.2% for S. metallicum, 46.9% for S. callidum and 38.9% for S. mexicanum. The parous rate showed diurnal change, those of which captured in the afternoon being somewhat higher. The survival rate of S. ochraceum for 9 days after blood-feeding when this species become infective, was estimated at 27.3%
