Title: Effect of a thinly-dispersed egg condition during the incubation period on the hatching of the West Indian sweetpotato weevil, Euscepes postfasciatus (Coleoptera: Curculionidae).
Abstract:Egg incubation of Euscepes postfasciatus is a necessary step in the mass rearing of this species because its egg period is slightly long (mean, 8 days at 25°C). E. postfasciatus eggs tend to stick to ...Egg incubation of Euscepes postfasciatus is a necessary step in the mass rearing of this species because its egg period is slightly long (mean, 8 days at 25°C). E. postfasciatus eggs tend to stick to each other during the incubation period. To ensure sufficient disinfection of the egg surface and an even distribution of the eggs on the artificial diet, it is necessary to separate the stuck eggs. The separation process is time-consuming; it can be shortened by ensuring, as far as possible, that the eggs are not in contact with each. The effect of the incubation condition on egg hatching of E. postfasciatus has not yet been examined; thus, we compared the parameters for hatching between eggs incubated en masse (the present method) and those that had been thinly dispersed (a newly tested method). The eggs could be dispersed easily by putting eggs on a well-strained nylon cloth and gently swaying the cloth in water. The hatchability, mean egg period, and variance of the egg period did not vary significantly between the two incubation conditions. The separation time of E. postfasciatus eggs can thus be shortened without any undesirable effects on egg hatching of the species.Read More