Efficacy of insecticides against citrus psylla (Diaphorina citri Kuwayama) in field and laboratory conditions

Abstract

The experiments were conducted in a citrus orchard to check the efficacy of insecticides against citrus psylla, and mortality was observed after three days, seven days and then after one month. Four insecticides, Polytrin-C, Talstar, Bifenthrin and Imidacloprid applied, had an almost equal effect on the population reduction of citrus psylla on all citrus plants. The trial was laid out in randomized complete block design (RCBD) having five treatments with three replications in a citrus orchard, after three days of spray showed percentage control as 96.91%, 94.33%, 93.83% and 93.06% of following insecticides Polytrin- C, Imidacloprid, Bifenthrin and Actara, respectively, calculated by Minitab 15. Psylla adults were exposed to different concentrations (500, 400, 300, 200 and 100 ppm) of Imidacloprid and Bifenthrin, and two controlled conditions (with leaves and without leaves). Both Imidacloprid and Bifenthrin insecticides proved to be the most effective against D. citri with lethal times (LT50s) of 4 and 5 hours, respectively, at a concentration of 500 ppm, calculated from probability test with Minitab-15.