Evaluation of Safety of Some Insecticides on Predatory Spiders in Rice Ecosystem

An experimental trial in rice was conducted during kharif seasons of 2016 and 2017 at the Agriculture Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi to evaluate the effect of conventional and newer insecticides viz., carbofuran 3%G @ 750 g a.i./ha, thiamethoxam 25%WG @ 25 g a.i./ha, fipronil 5%SC @ 50 g a.i./ha, lambda-cyhalothrin 5%EC @ 20 g a.i./ha, neem (Azadirachtin 0.15%EC) @ 4 ml/l., flubendiamide 20%WG @ 25 g a.i./ha, chlorantraniliprole 18.5%SC @ 30 g a.i./ha, acetamiprid 20%SP @ 35 g a.i./ha, dinotefuran 20%SG @ 40 g a.i./ha and pymetrozine 50%WG @ 7.5 g a.i./ha on spiders inhabitants of rice system. Except lambda-cyhalothrin 5%SP nearly all the insecticidal treatments showed slight effects against the spiders occurring in rice ecosystem. The results revealed that flubendiamide 20%WG @ 25 g a.i./ha was the least toxic, allowing maximum occurrence of spiders (excluding untreated control). Thus, it can be considered in IPM for the best control of insect pests. Similarly, chlorantraniliprole 18.5%SC @ 30 g a.i./ha followed by fipronil 5%SC @ 50 g a.i./ha were also found safe to spiders.