Estimation of Production Potential of Host Insect Corcyra Cephalonica (Stainton, 1865) (Lep., Pyralidae) on Different Diet Combinations to Produce Trichogramma Chilonis
Biological control of crop pest is a safe, economic and eco friendly approach in integrated pest management. Recent research emphasises the importance of mass rearing of bio control agents for augmentation & field releases. For mass production of many parasitoids and predators, Corcyra cephalonica has been the most suitable host insect in many laboratories (Jalai and Singh, 1992). Although there are several egg parasitoids commonly used throughout the world, Trichogramma have been the most extensively studied and promising. The rearing host diet is potentially importance to the nutritional quality of host eggs and the survival of parasitoids released into the environment as biological control agent (Hunter, 2003).Therefore it is necessary to study the effect of host rearing media on nutritional quality of Corcyra eggs on which Trichogramma chilonis is reared. In view of its potential importance to biological control programmes, an attempt was made in the present study to determine the economic efficiency of rearing media for Corcyra using sorghum, Pearl millet (bajra), finger millet (raagi), broken rice and foxtail millet (korra) in different combinations with the objective to study the Effect of different rearing media on growth and development of Corcyra cephalonica considering economy. The present experiment was conducted in the period from 02.03.2014 to 25.06.2014 at Centre for biological control (CBC), National institute of plant health management (NIPHM), Hyderabad to determine low cost, efficient rearing medium for rearing Corcyra cephalonica and to compare the diet options in terms of Biology Corcyra cephalonica. Experiment was conducted in controlled conditions i.e.; 25±1 ºC & 55±10% RH. The seven different rearing media were prepared by using cereal grains like sorghum, bajra, raagi (Finger millet), korra (Foxtail millet), maize & broken rice in different combinations. Seven different biological parameters of host insect have been taken under consideration to evaluate production potential of host insect influenced by diet combinations. Most of the parameters were found significantly higher in Bajra based medium T1 (Bajra+sorghum), which can be used profitably in mass multiplication of Corcyra cephalonica and the next best alternative being T4 (bajra+raagi) as well as T6 (Bajra+broken rice) and these two were found to perform better over other diet combinations made of maize, rice and korra grains.