Susceptibility of several varieties of soybean to Ephestia cautella (Walker) (Lepidoptera: Phycitidae)

Ephestia cautella (Walker) was reared on 39 varieties of soybean at 30 ± 1°C, 80 ± 5% r.h. and 12 hr light: 12 hr dark photoperiod. Larvae were reared individually on whole grains and flours of each variety and larval period, pupal period, per cent pupation and per cent adult formation were recorded. Larvae failed to develop on grains of 13 varieties while grains of Grant, Clark glabrous, Clark dense, Henry, Harrowmanchu and Hawkey-63 were highly susceptible to this pest. On the other hand larvae completed development successfully on all 39 varieties when seeds were ground into flours. It was also clear that UPSM-158 was somewhat tolerant to the attack of this pest while UPSM-120, Hawkey-63, Clark-63, Chippewa, UPSM-57, Harrowmanchu, Hampton, Goldsoy, Davis, Hood, and Kohachugatsu were also less efficient in supporting the development. Addition of 5% yeast to these varieties produced remarkable improvement in the quality of the diet which indicated that the flours of these varieties were deficient in one or more essential nutrients.