The present study was carried out at Kaydam Swat to assess the bio-efficacy of different treatments viz., Karate 2.5 EC, Emmamectin Benzoate 1.9 EC, Confidor 20 SL,DDVP 80 EC and untreated check against the Walnut Stem borer, Aeolesthes sarta Solsky on Walnut trees. In all the treatments the borer holes were plugged with mud after treatment application while plain mud plastering was done in control. Results of the post-spray data recorded after 7 and 14 days revealed that all the insecticides were significantly effective in reducing the larval population of the pest as compared to the untreated check but DDVP gave best results (82.32%) in terms of reducing the pest population 14 days after treatment.