Influence of Bt corn (Yieldgard) on the Population of Natural Enemies of Asian Com Borer, Ostrinia Furnacalis (Guenee)
The influence of Bt corn (YieldGard) and its isohybrid (non-Bt corn) on the population of Asian corn borer (ACB), Ostrinia furnacalis (Guenee) and its associated natural enemies was evaluated during the 2003 crop seasons in Echague and Cauayan both in Isabela, Philippines. Significantly higher numbers of ACB egg masses were recorded in Bt corn (Mort 810) as compared to its isohybrid during the dry season. Trichogramma parasitism, population of flower bugs (Orius tantillus), coccinellid beetles (Micraspis discolor) and spiders were also higher in Bt corn plants than in the isohybrids. ACB damage was not recorded in Bt corn. In spite of the very high egg mass population recorded, the isohybrid corn was almost totally free from ACB damage prior to harvesting due to very high natural enemy population. These natural enemies may play a significant role in controlling ACB and contribute in delaying the development of ACB resistance to Bt corn. Results further suggest that in areas where natural enemy population is relatively high, it may not be necessary to use Bt corn; instead, the ordinary hybrid can be planted. In terms of ACB-resistance management, this could be an alternative means of providing refuge for Bt-susceptible ACB. Although few coin borers and its natural enemies were found during the wet season cropping, the damage caused by ACB was high which resulted in very low yield of isohybrids. The Bt corn plants provided an average yield advantage of about 5.3 tons/ha over the isohybrids. Therefore, planting of Bt corn offers better advantage because the farmers practice of 3-5 sprayings directed against ACB is still insufficient to control the pest.
Isohybrid Bacillus thuringiensis Trichogramma Orius Micraspis Spiders
P.A. Javier M.V. Agsaoay J.L. de la Cruz
National Crop Protection Center, University of the Philippines, Los Banos, College, Leguna, Philippi Pangasinan Agricultural College, Pangasinan, Philippines Formely with Isabela State University, Echague, Isabela, Philippines
国际会议
第九届亚洲玉米大会(the Ninth Asian Regional Maize Workshop)
北京
英文
191-194
2005-09-05(万方平台首次上网日期,不代表论文的发表时间)