TY - JOUR AU - Karthikeyan, K. AU - Jacob, Sosamma AU - Purushothaman, S. M. PY - 2007/12/15 Y2 - 2024/03/29 TI - Field Evaluation of Egg Parasitoids, Trichogramma japonicum Ashmead and Trichogramma chilonis Ishii, against Rice Yellow Stem Borer and Leaf Folder JF - Journal of Biological Control JA - JBC VL - 21 IS - 2 SE - Articles DO - 10.18311/jbc/2007/3858 UR - https://informaticsjournals.com/index.php/jbc/article/view/3858 SP - 261-265 AB - Field evaluation of two egg parasitoids, <em>Trichogramma japonicum</em> Ashmead against rice stem borer, <em>Scirpophaga incertulas</em> (Walker), and <em>Trichogramma chilonis</em> Ishii against leaf folder, <em>Cnaphalocrocis medinalis</em> (Guenee), was carried out in farmers' fields in three locations at Karakkad village, Palakkad district, Kerala, during three seasons in 2003 and 2004 in comparison with insecticide application. Release of <em>T. japonicum</em> @ 100000/ha followed by application of azadirachtin 1 per cent against yellow stem borer reduced dead hearts from 12.21 to 91.02 per cent and from 27.4 to 58.2 per cent over insecticide application during <em>kharif</em> and <em>rabi</em> seasons, respectively. Incidence of white ears was reduced by 72.41 to 92.86 per cent. <em>T. chilonis</em> reduced leaf folder damage by 41.68-98.60 per cent over conventional insecticide application. Release of egg parasitoids in rice resulted in an increase of yield by 25.79-45.13 per cent over insecticide treated plots, with a mean cost-benefit ratio of 1:2.6 and 1:1.9 in parasitoid released and insecticide applied plots, respectively. ER -