Pak. J. Agri., Agril. Engg., Vet. Sci., 27 (2), 2011 176 ISSN 1023-1072 Pak. J. Agri., Agril. Engg., Vet. Sci., 2011, 27 (2): 176-184 FIELD PERFORMANCE OF TRICHOGRAMMA CHILONIS AGAINST COTTON BOLLWORMS INFESTATION IN DIFFERENT COTTON VARIETIES AS A SUSTAINABLE IPM APPROACH 9 A. Masood 1 , M. J. Arif 1 , M. Hamed 2 and M. A. Talpur 3 1 Department of Entomology, University of Agriculture, Faisalabad, Pakistan 2 Plant Protection Division, NIAB, Faisalabad, Pakistan. 3 Department of Plant Protection, Sindh Agriculture University Tandojam, Pakistan ABSTRACT The experiment was conducted on six cotton varieties to evaluate the performance of Trichogramma chilonis against the infestation of Helicoverpa armigera and Earias insulana at Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. Data regarding percentage infestation from biological control plot and unsprayed plot was recorded at weekly interval. It was observed that due to the presence of egg parasitoid, H. armigera damage, reduction over control was ranging from 31.73 to 36.45 % on cotton varieties, i.e. SLH-279, FH-945, NIAB-111, CIM-499, CIM-707 and FH-901, respectively. While E. insulana reduction percentage was 32.43 to 45.49 % less compared to control on the same varieties mentioned above. However, maximum suppression of H. armigera (49.71%) was observed on NIAB-111 during 2 nd week of September and E. insulana 54.99% on SLH-279 during 1 st week of August followed by 52.68% (NIAB-111) during 1 st week of October. It is concluded that Trichogramma chilonis is successfully used as biological agent in integrated pest management program. Keywords: Bollworms, cotton varieties, Earias and Helicoverpa spp, Trichogramma INTRODUCTION Cotton is the lifeline of Pakistan's economy and crises that decrease the production of this commodity can adversely affect the economy, therefore plays an important role in the economy of Pakistan and generates significant proportion of foreign exchange. Cotton accounts for 7.3 percent of the value added in agriculture and about 1.6 percent to GDP. The crop was sown on the area of 2820 thousand hectares, 7.7 percent less than last year 2007 (3054 thousand Corresponding author: fsdasad@gmail.com