Recycling of spent larval food of Corcyra cephalonica for fuel gas production

Commercial production of the egg parasitoid, Trichogramma chilonis Ishii (Trichogrammatidae: Hymenoptera) needs a continuous egg supply of Corcyra cephalonica Stainton (Pyralidae: Lepidoptera). Larvae of C. cephalonica are reared in pearl millet grains in commercial laboratories and the disposal of accumulated spent larval medium (90 days after usage) poses a problem. Experiments conducted to recycle the biowaste indicated that anaerobic digestion of spent larval medium with cow dung slurry at 1:3 and 3:1 ratio produced higher total biogas and fuel methane output equal to cow dung slurry alone. Spent larval medium alone, however, resulted in minimum biogas and methane output.