Insecticides to control <i>Anticarsia gemmatalis</i> (Lepidoptera: Noctuidae) and its impact on predatory spiders in soybean crop

Abstract

The effect of insecticides to control Anticarsia gemmatalis and its impact on predatory spiders in soybean crop was evaluated. The experimental design  was randomized blocks consisting of eight treatments and four replicates. The treatments were: 1) ethofenprox (0,2 L of p.c/ha); 2) ethofenprox (0,25 L of p.c/ha); 3) ethofenprox (0,3 L of p.c/ha); 4) acephate (0,3 kg of p.c/ha); 5) acephate (0,4 kg of p.c/ha); 6) lambda-cyhalothrin (0,015 L of p.c/ha); 7)  deltamethrin (0,14 L of p.c/ha) and dichlorvos (0,28 L of p.c/ha) and 8) Control (without insecticide). The total number of predators was evaluated before  the application of the products and 1, 3, 7, 14 and 21 days after the application (DAA). The efficiency of the insecticides was calculated using the Abbott equation. The percentage of the resulting mortality of predators was separated in classes suggested by the IOBC. The results showed that the tested insecticides were effective to control A. gemmatalis up to 7 DAA. Regarding the insecticides impact on predatory spiders, there was low influence of them on the populations of arachnids at 14 and 21 DAA, which allowed fast recovery of those populations.