author(s)
Narava Ramana, RS Bandral, RK Gupta and Sachin Gupta

abstract
The experiment was conducted to evaluate the persistent toxicity of insecticides viz., methyl-o-demeton, spinosad, acetamiprid, chlorfenapyr, and fipronil against neonate mustard aphid, Lipaphis erysimi. Mean aphid mortality of mustard aphid revealed that methyl-o-demeton (0.03%) exerted superior mortality (93.75%) after 1 hour of spraying but acetamiprid was the most effective insecticide after one, three, seven and ten days of spraying. Fipronil and chlorfenapyr were at par with methyl-o-demeton (0.03%). Whereas, spinosad was the least effective insecticide. Mean aphid mortality on twigs has also revealed that acetamiprid was the most promising insecticide. Based on persistence toxicity values the order of persistent toxicity (PT) was acetamiprid (612.9) > methyl-o-demeton (593.8) > fipronil (530.4) > chlorfenapyr (482.8) > spinosad (459.2).