Compatibility of Chemical and Biological Control for the Management of Maize Stem Borer, Chilo Partellus, (Swinhoe) (Lepidoptera; Pyralidae)

With a view to use Trichogramma chilonis as parasitoid in the integrated pest management of Chilopartellus in maize field, basic studies on the efficacy of some insecticides against Chilo partellus in Jalal varietyof maize and selectivity for the bio-control agent, T. chilonis were carried out under field conditions at AgriculturalResearch Institute, Tarnab Peshawar during 2016. Treatments viz Proclaim (Emamectin benzoate®1.9 EC) + T. chilonis, Confidor® (Imidacloprid 200 SL) + T. chilonis, Chlorpyrifos® 40 EC + T. chilonis, Neemseed extract + T. chilonis and release of T. chilonis alone were applied to the Jalal variety. For C. partellus infestation,the data was recorded on the basis of leaf injury scale from 1 to 5 and percent dead hearts. Resultsshowed that Imidacloprid + T. chilonis resulted in significantly lower leaf injury m-2 (1.32) and dead hearts(4.16 %) closely followed by the plots treated with emamectin benzoate + T. chilonis with leaf injury m2 (1.74)and dead hearts (7.50 %) while significantly higher leaf injury m2 (3.64) and dead hearts (20.0 %) were recordedin control plots. Yield data followed almost the same pattern as observed in case of leaf injury and deadhearts. Significantly lower yield was recorded in the control plots (3.54 ton-ha), while significantly higher yieldwas recorded in the plots treated with imidacloprid (6.61 ton-ha) followed by emamectin benzoate (6.10 ton-ha)treated plots. Results of the field test showed that significantly higher (88.0 %) parasitism of host eggs by T.chilonis was recorded in T. chilonis alone released plots followed by neem extract of (69.33 %) parasitism, imidaclopridwith (65.33 %) parasitism, while significantly lower (30.66 %) parasitism was recorded in chlorpyrifostreated plots. We conclude from this experiment that for the management of C. partellus, Imidaclopridis recommended as it exhibited high level of selectivity for T. chilonis parasitization capacity. However, furtherinvestigation is needed to study the effect of these chemicals on the whole life cycle of T. chilonis.