Determination of multiple-species economic injury levels for rice insect pests

摘要: Abstract Yield loss to damage functions were established determine multiple-pest economic injury levels (EILs) on Pusa Basmati 1 rice ( Oryza sativa L.) at different crop growth stages through field and pot experiments in 2009 2010. The yield derived for two-pest combinations of leaf folder, Cnaphalocrocis medinalis Guenee, stem borers, Scirpophaga incertulas (Walker) Sesamia inferens (Walker), reproductive stage during folder planthoppers, Nilaparvata lugens (Stal.) Sogatella furcifera Horvath, vegetative stage, planthoppers borers Single-species as well multi-species EILs determined. Across experiments, single-species borer ranged from 2.9–6.4% folded leaves 1.9–3.0% whiteheads, respectively, while that varied between 5.5 7.3 hoppers per hill. Iso-loss equations, based functions, depicted various incidence which resulted damage. These joint showed that, although each pest was below its EIL, the combination both pests inflicted multi-pest can be useful monitor simultaneous occurrence species thereby helping prevent losses.