A Simple Mass-Rearing Technique of the Diamond-Back Moth, Plutella Xylostella (L.), on Germinating Rape Seeds

Abstract

A simple technique for mass-rearing of the diamond-back moth was deviced using the seedlings of rape, Brassica napus, germinated densely in plastic vessels (dia. 9.5cm×5.5cm) with tops having a screen hole. Eggs were laid on the germinating rape seeds by moths released for 2 or 3 days just after the germination. The larvae were allowed to feed on cotyledons and stems of the seedlings soon after the germination. When 3 pairs of the moths were released in each vessel containing the seedlings germinated from 7g of seeds by adding ca. 4ml of water, most of the larvae completed their development and about 100 pupae were obtained in 15 days after releasing the moth at 25°C. The density of about 100 larvae per vessel seemed appropriate showing the good pupation of higher than 90%. The larval duration, the pupal body weight, and the fecundity of resultant moths were also as good as those of the populations fed on the cabbage leaves. The larvae could be reared without changing the seedlings. A folded filter paper was inserted onto the seedlings in each vessel as a pupation site, so that the pupae could be gathered easily. Rearing of successive generations on the rape seedlings could be accomplished. This rearing method is well suited for the continuous mass production of the diamond-back moth in the laboratory. © 1976, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.