Standardization of egg dosages for mass production of Corcyra cephalonica (Stainton)

Abstract

Rice moth, Corcyra cephalonica (Stainton) has been widely used as an efficient alternative host for the mass rearing of many biocontrol agents. With aim to increase production competence, egg dosages required for the initiation of its rearing culture were assessed. Each Corcyra rearing box containing 2.5 kg of milled sorghum was charged with different volume of eggs, i.e., 0.33 cc, 0.25 cc, 0.20 cc, 0.167 cc, 0.143 cc and 0.125 cc eggs and different parameters like larval period, first day to adult emergence, moth emergence, eggs production in F1 generation and fecundity per female were worked out. The larval period varied from 42 to 54 days and it increased with increase in volume of eggs per box. First adult emerged after 58.4 days in boxes charged with 0.33 cc eggs, which was significantly higher than other dosages (46.3 to 51.9 days). Moth emergence period in rearing boxes varied from 38 to 56 days in different dosages. Moth production per box (899.8 moths) was significantly higher at egg dosage of 0.20 cc followed by 0.25 cc, wherein 821.3 moths emerged. Similarly, egg collection in F1 generation was also maximum (8.63 cc) in boxes with initial dosage of 0.20 cc eggs per box, resulting in 43.15 fold increase as compared to volume of eggs used initially. In conclusion, the studies suggested that the optimal inoculative eggs for rearing of C. cephalonica should be 0.20 cc/box, each having 2.5 kg of milled sorghum for maximizing its production competence.