Safety Studies Of Chlorantraniliprole On Main Predatory Natural Enemies In Double-Cropping Paddy Fields

Instead of natural control to the pests, long-term and frequent application of chemical insecticides had destroyed the balance of ecosystem. Due to the advantages of convenience, simplification and economization, chemical insecticides was widely used and regarded as an important means of pest management at present when environment protection was stressed deeply. It was significant to harmonize chemical management and bio-control for the function of natural enemies. This paper was divided into three parts:Partâ… tested the toxicity of 3 insecticides, which were Chlorantraniliprole Metaflumizone and Avermectins, to two kinds of spiders; Partâ…¡contained the effects of 3 kinds of insecticides on main predatory natural enemies; In partâ…¢we had discussed the effects of those different insecticides on community diversity of main predatory natural enemies. The results were summarized as follows:1. The results of the toxicity of 3insecticides, which were Chlorantraniliprole Metaflumizone and Avermectins, to two kinds of spiders showed that the toxicity of Chlorantraniliprole to spiders was very small, and even smaller to large spiders; Avermectins had great toxic on spiders. The highest toxicity of Avermectins to Pirata subiraticus was 7.7 times higher than that of Chlorantraniliprole (in the same period of 14d). The lowest toxicity of deltamethrin to Pirata subiraticus was 13.8 times higher than that of Chlorantraniliprole (in the same period).2. There were seven times using of insecticides in the double-cropping paddy field. Chlorantraniliprole had low effect on the population of main predatory natural enemies, such as spiders, Coccinellidae sp., Microvelia sp., Paederus sp., Cyrtorrhinus sp. in rice growth stages, which was similar to those of contrast. The had high effect on the population of main predatory natural enemies.3. Based on preliminary investigation in fixed position in Xiangyin,41 species 13 families of spiders and 4 other main species of insect natural enemies were found in the community of predatory natural enemies of double-cropping paddy fields. The dominant of the spider community were Pardosa Pseudaannulata, Pirata Subiraticus, Pirata Pibberum, and so on. The 4 other main species of insect natural enemies were Coccinellidae sp., Microvelia sp., Paederus sp. Cyrtorrhinus sp,. The Avermectins had high effect on the population dynamics of main predatory natural enemy community, and Chlorantraniliprole had low effect on it. The ecological parameters, diversity index, richness and evenness, were used to evaluate effects of two sorts of insecticides on predatory natural enemy community. The results showed that the Avermectins decreased diversity index and richness, and had strong interference on the stability of predatory natural enemy community. Chlorantraniliprole had very low influence on predatory natural enemy community, and its parameters were similar to those of contrast.