A simple improved diet for mass rearing of sorghum stem borer, Chilo zonellus Swinhoe.

Abstract

A larval diet based on a wheat-germ diet developed for rearing Diatraea (Zeadiatraea) grandiosella Dyar [RAE/A 54, p. 34] was used for the mass rearing of Chilo partellus (Swinh.) (zonellus (Swinh.)) in India [cf. 58, 301], but it was expensive, was subject to fungus growth and permitted heavy larval mortality. Four new diets were therefore tested. Observations for two generations showed that a medium containing 420 g flour made from Cicer arietinum (kabuli gram), 3120 ml water, 51 g agar, 40 g yeast, 13 g ascorbic acid, 8 g methyl p-hydroxybenzoate, 4 g sorbic acid and 8 ml 10% formaldehyde resulted in healthier larvae, larger numbers surviving to the adult stage and greater female fecundity than did the original wheat-germ diet, the kabuli-gram diet made with pre-soaked flour, or diets with the gram flour replaced by 748 g soy-bean and maize mixture or by 420 g presoaked powder of pinto bean (Phaseolus vulgaris) and 200 g wheat germ. No fungus developed on the dry kabuli-gram flour diet