Stromata production for Cordyceps militaris (Clavicipitales

Alternative host insects for simple stromata production of Cordyceps militaris were investigated to derive ascospores for infection tests. The stroma production of this fungus was examined by injecting a suspension of its hyphal bodies into three species of lepidopteran pupae (Mamestra brassicae, Spodoptera litura, Bombyx mori) and a species of coleopteran pupae (Tenebrio molitor). C. militaris killed the pupae of all four insects and produced mature stromata from them at between 20 and 500 lx, and at 20 and 25°C, showing a shorter maturation period at 25°C. Ascospores derived in this study germinated. Use of lepidopteran pupae is thought to be suitable for deriving ascospores because of nearly synchronous maturation of stromata compared to those of T. molitor. These findings suggest that artificial injection increases the range of insects that C. militaris can use to produce stromata.