Eggs fertility and biological aspects of the life cycle in natural populations of Simulium (Diptera, Simuliidae)

English. Eggs fertility rate and some biological aspects of the immature forms were studied on six Simulium species from ovipositions collected in natural breeding places located in rural area. The fertility was considerably high. For a total of 213 ovipositions containing 74,906 eggs, the average fertility rate was 99.13% with variation from 94 to 100%. The developmental cycle of the immature forms was observed from egg eclosion to adult emergence under temperature from 16.5 to 28ºC. In S. orbitale the life cycle duration was 30 to 32 days, for S. perflavum 32 to 35 days, for S. subnigrum 33 to 39 days, for S. inaequale 41 to 47 days, for S. pertinax 42 to 48 days, and finally, the longest duration was observed for S. distinctum to range 48 to 49 days.

Portuguese. Foram estudados o índice de fertilidade de ovos de espécies de Simulium e o ciclo biológico das fases aquáticas em posturas trazidas de criadouro natural localizado na área rural. A fertilidade de ovos mostrou-se altíssima, das 213 posturas coletadas, contendo 74.906 ovos, o índice médio percentual geral foi de 99,13%. Entre as diferentes posturas, a variação oscilou de 94% a 100%. O ciclo biológico a partir da incubação do ovo até a emergência de adulto em Simulium orbitale foi de 30 a 32 dias; Simulium perflavum de 32 a 35 dias; Simulium subnigrum de 33 a 39 dias, Simulium inaequale de 41 a 47 dias; Simulium pertinax de 42 a 48 dias e Simulium distinctum de 48 a 49 dias em temperaturas com variação de 16,5ºC a 28ºC.