Dietary Composition and Biological Performance of Corcyra cephalonica (Stainton) on Maize-based Diets Under Laboratory Conditions

Abstract

The present investigation was carried out from November, 2024 to January, 2025 at the Hi-Tech Laboratory, Sugarcane Research Institute, Dr. Rajendra Prasad Central Agricultural University (RPCAU), Pusa, Bihar, India, to assess the effect of seven maize-based diets on the biological and economic performance of Corcyra cephalonica (Stainton) under laboratory conditions. Corcyra cephalonica (Stainton), commonly known as the rice moth, was recognized as a serious stored-grain pest and an important factitious host for the mass production of egg parasitoids and other natural enemies used in biological control programmes. Providing an efficient and economical rearing diet was crucial, as diet quality directly influenced insect development, reproductive potential and the reliability of biocontrol production systems. The treatments included maize alone (standard check) and maize mixed in a 1:1 ratio with wheat, rice, barley, sorghum, bajra and ragi, all fortified with yeast, groundnut, streptomycin sulphate and wettable sulphur. Diet composition significantly influenced developmental and reproductive parameters. Among all treatments, the maize+sorghum diet proved to be the most suitable, as it resulted in the shortest incubation, larval and pupal periods, the shortest total developmental duration in both sexes, higher adult and female emergence, maximum fecundity and greater total egg production. This diet also recorded the highest net profit (` 1181) with a favourable benefit–cost ratio (3.31), highlighting its economic viability for mass rearing. In contrast, the maize+barley and maize+ragi diets prolonged development and reduced emergence and reproductive performance. Overall, the study demonstrated that maize+sorghum was an efficient and cost-effective diet for large-scale laboratory rearing of C. cephalonica, thereby supporting sustainable biological control programmes.