Evaluation of some neem-based formulations as oviposition deterrents against brown planthopper and yellow stem borer of rice

摘要

Nine neem -based chemicals and neem oil were evaluated for their efficacy as oviposition deterrents against brown planthoper (BPH) and yellow stem borer (YSB) of rice. Some of the products like Neemazole-F, Nethrin and neem oil in the case of BPH andNethrin, Margocide CK and Margocide OK in.the case of YSB showed reduced rate of oviposition, which was just below 50%. But, in others it was above 50 % level. All the chemicals, including neem oil, showed high percentage of nymphal and larval hatching,indicating that none of them possessed any ovicidal action against both the pests.