Comparison of toxicity and selectivity of the pest Bactericera cockerelli and its predator Chrysoperla carnea
Chemical and biological control in sustainable management requires understanding the risks, selectivity and conditions of use for insecticides, in order to maximize their compatibility. Therefore, the tolerance of Chrysoperla carnea and Bactericera cockerelli to field concentrations of 18, 180, 1200, 1300 and 1400 ppm L-1 of the insecticides abamectin, bifenthrin, endosulfan, imidacloprid and profenofos was evaluated, and, in addition, their selectivity on predator Chrysoperla carnea. The selectivity proportion of insecticides to C. carnea was calculated through the relation SP=CL50 of the insecticide for the natural enemy/CL50 of the insecticide for the plague. Abactemin, bifenthrin and endosulfan were more toxic for B. cockerelli than for C. carnea. Profenofos was highly toxic for both species and imidacloprid was more toxic for C. carnea. The values for the selectivity proportion were 1072.84, 14.33, 6.07, 0.61 and 0.11 for abamectin, endosulfan, bifenthrin, profenofos and imidacloprid, indicating that abamectin was highly selective, endosulfan and bifenthrin were selective and profenofos and imidacloprid were not selective for the predator.