author(s)
Neha Sharma, SN Upadhyaya, UC Singh, Megha Dubey and Anjum Ahmad

abstract
The present investigations were conducted at the experimental site of entomological research farm, College of Agriculture, Rajmata Vijayaraje Scindia Krishi Vishwa Vidyalaya, Gwalior, Madhya Pradesh during 2011-12 and 2012-13. Bio-efficacy of nine insecticides namely, acephate, acetamiprid, oxy-demeton methyl, dimethoate, Imidacloprid, carbosulphan, flonicamid, thiamethoxam and fipronil were studied against mustard aphid, Lipaphis erysimi (Kalt.) and their effect on its natural enemies, Coccinella septempunctata under field condition. Mean aphid population (after three sprays, nine observations, average taken over two years) showed significant superiority of insecticide treatments against control. Imidacloprid was found most effective followed by Thiamethoxam and Oxy -dameton methyl. Carbosulphon was least effective followed by flonicamid and fipronil as given in table 5. All the insecticidal treatments proved significantly superior registering high grain yield. With regard to yield all the insecticides treatment proved significantly superior registering higher yield (980 to 1425 kg/ha) than control (780kg/ha). The maximum grain yield (1425 kg/ha) was obtained with Imidacloprid treated plot followed by Thiamethoxam and Oxy -demeton methyl. Whereas, Carbosulphon recorded the lower yield (980 kg/ha) and was at par with Flonicamid. In control, the yield obtained was (780 kg/ha). The cost benefit ratio ranged from1: 1.52 to 1:13.28. Highest incremental cost benefit ratio with highest return was obtained from (1:13.28) with Imidacloprid followed by Dimethoate (1:9.88) and Oxydemeton-methyl (1:9.15). Poor incremental cost benefit ratio was obtained from Flonicamid (1:1.52) followed by Fipronil (1:3.30).