INSETICIDAS NAS SEMENTES E A ENTOMOTOXINA CRY 1 AC PROTEGEM A SOJA CONTRA A LAGARTA-DO-VELHO-MUNDO

INSECTICIDES IN SEEDS AND ENTOMOTOXIN CRY 1 AC PROTECT SOYBEANS AGAINST THE OLD-WORLD CATERPILLAR

Abstract

The Helicoverpa armigera caterpillar occurs from the emergence of the plants to the reproductive stage of the soybean crop, which can cause significant losses. As an initial pest, both neonate and more developed caterpillars can be found, the latter from the previous crop.The use of Bt cultivars and insecticides in seed treatment are options to pest management at the beginning of soybean development, but there are doubts about the efficacy of these control methods. Thus, the objective was to evaluate the protective effect of insecticides applied to seeds and Cry 1Ac protein, in relation to the attack of the H. armigera caterpillar, as an initial pest in soybean plants. Our results confirm that under laboratory conditions the insecticides cyantraniliprole (60 g ai / 100 kg of seeds) and chlorantraniliprole (62.5 g ai / 100 kg of seeds) protect the soybean against the injuries of H. armigera 3º-4º instars, in cotyledons and unifoliolate and trifoliolate leaves, at 5 days after the emergence of the plants. The protein Cry 1Ac protects the soybean plants from this type of injury caused by both 3^rd-4^th and 5^th-6^th instars caterpillars, at 5 and 10 days after emergence.