Toxicidade de peticidas para adultos de Orius insidiosus (Say, 1832) (Hemiptera: anthocridae)

Abstract

Predators of the genus Orius feed on many pests of economic importance, such as thrips, whiteflies, aphids, mites, eggs and small lepidopteran larvae, contributing to their population control. Thus, this work investigated the toxicity (g a.i. 100 L-1 of water) of the pesticides mancozeb (160), chlorothalonil (150), lufenuron (15), dicofol (36), bifenthrin (2), triazophos (40), methomyl (21.5), and acetamiprid (6) used in chrysanthemum production on adults of the Orius insidiosus (Say) bug. The topical treatment consisted of using a Potter’s tower adjusted to 15 lb/ pol2 , with an application of 1.5 ± 0.5 mg of mixture/cm2 , on adults with age up to 48h. The toxicity of the pesticides for adults was determined by the percentage of the total effect (E%), taking into account the daily mortality during 8 days after treatment with the pesticides, and daily and total oviposition during 15 days. Then, the pesticides were ranked according to criteria proposed by the International Organization for Biological Control (IOBC). Based on the results, chlorothalonil was considered harmless to the predator (class 1), while mancozeb and dicofol were classified as slightly harmful (class 2), and lufenuron was considered moderately harmful (class 3). The remaining products, bifenthrin, triazophos, methomyl, and acetamiprid were ranked as harmful (class 4) to the predator O. insidiosus. Therefore, due to the low toxicity of chlorothalonil, mancozeb and dicofol, these compounds can be recommended in management programs for the conservation of this species of predator