Comparative Toxicity of Insecticides against Two Important Insect Pests of Cauliflower Crop

Study was conducted to test four insecticides, profenofos, emamectinbenzoate, λ-cyhalothrin and lufenuron against two field populations of Plutella xylostella and Spodoptera lituraat different larval instars during 2010-11. The field populations collected from Rawalpindi and Taxila cauliflower fields was tested using leaf dip bioassay method under laboratory conditions. Results showed that emamectin benzoate was the most toxic insecticide for both P. xylostellaand S. litura. However, profenofos was the second most toxic insecticides to different larval instars of S. lituraand λ-cyhalothrin to P. xylostella.High LC50 values for lufenuron for this limited time exposure might be due to its slow acting as chitin synthesis inhibitor.Emamectin benzoate can be suggested as the most effective insecticides against both field populations along with profenofos and λ-cyhalothrin.