Determining the time required to ensure mating in bivoltine silkworm (Bombyx mori L.)

Abstract

The silkworm is an economically important insect known for its uniqueness in silk production. Oviposition is an important aspect of insect seed production which needs in-depth study. The aim of this study was to determine the effect of the mating period on the fecundity, egg fertility and performance of bivoltine silkworm. Adult males and females were allowed to mate for 1, 2, 3, 4, 5, and 6 hours respectively. The eggs laid by the mother moth were acid treated, incubated and hatched larvae were reared following standard protocol. The treatments were replicated 5 times and laid out in a Completely Randomized Design. Data were collected on female fecundity, egg fertility, larval and pupal weights, larval survival and cocoon parameters. Data were subjected to analysis of variance and means were separate using DMRT (P <0.05). The results showed that the number of egg laid, larval weight, number of cocoon harvested, shell ratio, effective rate of rearing, were significantly higher in progeny whose parent were allowed to mate for 1 hour. The cocoon weight, pupal weight and shell weight were highest in progeny whose parents were allowed to mate for 5 hours but not significantly different from the ones of other mating durations. There was a negative linear relationship between mating duration and hatchability (r=-0.88) at P<0.05. The study conclusively established that mating duration of 1 hour in bivoltine silkworm is enough to produce the best larval and cocoon performance. Hence 1 hour mating duration can be recommended for silkworm seed producers in the sericulture industry.

Keywords

• fecundity
• oviposition
• mating duration
• sericulture
• progeny