Toxicity of selected insecticides to different stages of brown lacewing,Micromus timidus Hagen (Neuroptera: Hemerobiidae)

Brown lacewings belong to the family Hemerobiidae and is the third largest family belonging to order Neuroptera. These are brown, small to medium-sized insects with moniliform antennae and are predators both in larval and adult stages, which feed exclusively on aphids. Investigation was made to study the sensitivity of Micromus timidus Banks to selected insecticides and the experiment was carried out in the Department of Entomology, University of Agricultural Sciences, Bengaluru. For the studies, five different insecticides (profenophos 50EC, imidacloprid 17.8SL, lambda-cyhalothrin 5EC, chlorantraniliprole 18.5SC and buprofezin 25SC) and a neem product (azadirachtin 10000 ppm) were selected based on the recommendation for aphid management in pulses. The toxicology studies were carried out by using the Potter spray tower and safety studies were carried out for all the four stages of M. timidus (egg, larva, pupa and adult). Control with water spray was maintained. For the egg and adult stages, imidacloprid 17.8SL at 0.5 mL/L was highly toxic causing 89.74 and 74.07 per cent mortality respectively, followed by profenophos 50EC at 3 mL/L (52.37 and 66.67 per cent mortality). The larval and pupal stages were very sensitive to profenophos 50EC at 3 mL/L causing 100 and 96.29 per cent mortality respectively, followed by imidacloprid 17.8SL at 0.5 mL/L (51.85 and 55.56 per cent mortality respectively). Azadirachtin 10000 ppm was found to be the safest insecticide to all stages of M. timidus, causing less than 20 per cent mortality, which was followed by buprofezin 25EC and chlorantraniliprole 18.5SC.