Development of immature stages in a blackfly Simulium kawamurae (Diptera : Simuliidae) observed in the laboratory

Abstract

Egg period and larval growth of Simulium kawamurae Matsumura were examined in the laboratory. Eighty-seven out of 96 wild caught gravid females (90.6%) laid eggs successfully in the laboratory. In total, 49.8% of the eggs developed and hatched. Median developmental period of eggs was 10.5,7.5,4.5,4.5 and 3.5 days from oviposition to hatch at 10,14,18,22 and 26±1℃, respectively. Larvae were reared with a stir-bar system, and pupation occurred 39-44 days (14℃) and 29-50 days (18℃) after hatch. Pupal periods were 5.5 days at 14℃ and 4-4.5 days at 18℃. There was no difference in preimaginal periods between sexes. Nine larval instars were recognized from postgenal length frequency distribution of larval exuviae. Five generations per year were expected in wild population based on the daily cumulative temperature for a life span of the species and annual temperature regime in the habitat.