Toxicidade residual de Clorantraniliprole + Abamectina em folhas de meloeiro sobre Apis mellifera.

Abstract

The honey bee Apis mellifera (Hymenoptera: Apidae) are essential for the pollination of several crops of agricultural importance, being the melon crop (Cucumis melo) one of them. In recent decades, several studies have drawn attention to the disappearance of bees in agricultural areas, with the abusive use of pesticides being one of the main factors mentioned. Therefore, it is necessary to conduct studies to assess the toxicity of insecticides on bees to contribute to the preservation and sustainable use of these insects. In view of the above, the aimed to evaluate the residual toxicity of commercial doses of the insecticide Chlorantraniliprole + Abamectin on A. mellifera in melon leaves. The work was carried out at the Entomology Laboratory concerning the CCTA/UFCG, Campus Pombal, in a completely randomized design in a 4x3 factorial scheme, where two commercial doses of the insecticide Chlorantraniliprole + Abamectin (0.0108 g i.a/L of Abamectin + 0.027 g i.a/L of Chlorantraniliprole and 0.018 g i.a/L of Abamectin + 0.045 g i.a/L of Chlorantraniliprole) recommended for the melon crop, a positive control (Thiamethoxam: 0.3 g i.a/L) and distilled water as an absolute control, as a function of three exposure times after spraying (1h, 2h and 3h after spraying). After exposure were evaluated for mortality and motor functions of bees during 1, 2, 3, 4, 5, 6, 12, 24 and 48 hours after initiation. After 48 hours, the fly hability of bees was avaluating. The insecticide Chlorantraniliprole + Abamectin, regardless of dose and exposure time, caused 100% mortality on A. mellifera. When the survival rate, it was observed that the median lethal time (TL50) of Chlorantraniliprole + Abamectin was lower than the TL50 of the absolute control and higher than the TL50 of the positive control, regardless of the exposure time after spraying each dose. Chlorantraniliprole + Abamectin proved to be highly toxic when in residual contact, regardless of doses and exposure interval.