Extraction of bioactive compounds from Streptomyces avermitilis and Azadirachta indica and Evaluation against Spodoptera litura: A green approach

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, there are morphological changes observed. By the GCMS analysis, five volatile compounds were observed from Bacterial extract and seven bioactive compounds detected from neem extract. Hence, for the future, integrated pest control is the possible solution to many insects and our result gives the rational solution to the pest control problem to the farmers due to their economic benefits and lowers social costs.