Comparative Toxicity of Insecticides against Two Important Insect Pests of Cauliflower Crop
Muhammad Imran1*, Kanwal Hanif2, Munir Ahmad2, Muhammad Nasir2, Umer Ayyaz Aslam Sheikh1
1Department of Entomology, Faculty of Agriculture, The University of Poonch, Rawalakot, AJ&K, Pakistan.
2Department of Entomology, Pir Mehr Ali Shah, Arid Agriculture University, Rawalpindi, Pakistan.
Abstract
Study was conducted to test four insecticides, profenofos, emamectin benzoate, λ-cyhalothrin and lufenuron against two field populations of Plutella xylostella and Spodoptera litura at 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. xylostella and S. litura. However, profenofos was the second most toxic insecticides to different larval instars of S. litura and 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.
Keywords:Spodoptera litura, Plutella xylostella, comparative toxicity, mode of action, age-dependent