author(s)
Vairamuthu Ajeeth Prakash, Ganesan Sermalatha and Thangamani Selvarathinam

abstract
The tobacco caterpillar, Spodoptera litura, is a crucial polyphagous pest on plants, which is present throughout the South and Eastern world. Extract of S. avermitilis in combination with A. indica performed well than the extract alone from Streptomyces avermitilis. And combined extracts of bacteria and neem have maximum mortality (100 per cent at 250 ppm), LC₅₀ value (124.85 ppm), LC₉₀ value (305.4 ppm) and antifeedant rate (64.6 ± 15.69 per cent) than the extract from S. avermitilis alone (Mortality = 92 percent at 250 ppm; LC₅₀ = 93.61 ppm; LC₉₀ = 243.49 ppm; Antifeedant rate = 59.6 ± 15.13 percent). When S. avermitilis extracts at the concentration of 50ppm are treated to the Spodoptera litura, morphological changes are observed. The GCMS analysis observed five volatile compounds from Bacterial extract and seven bioactive compounds detected from neem extract. Hence, integrated pest control is the possible solution for many insects in the future. Our result gives the farmers a rational solution to the pest control problem due to their economic benefits and lowers social costs.