In light of this and inspired by the remarkable pharmaceutical and agricultural potential of bioactive metabolites of actinobacteria, Kaur et al.  screened actinobacterial isolates, recovered from
different rhizospheric and non-rhizospheric soils, for antifungal activity against fungal phytopathogens and reported strong insecticidal activity against S. litura in one of the isolates, Streptomyces hydrogenans DH16 which also exhibited potent antifungal activity . Present study was aimed at further systematic evaluation of antifeedant, larvicidal, pupicidal and growth inhibitory effect of solvent extract from S. hydrogenans DH16 against S. litura. Results and discussion There is a long history of utilizing natural products produced by microbes for pharmaceutical and agricultural purposes. Actinobacteria especially, Streptomyces Selleckchem 4SC-202 spp. have provided wide variety of secondary metabolites of high commercial importance and continue to be APR-246 manufacturer routinely screened for new bioactive compounds. Present work further corroborates the earlier findings CP673451 and reports that secondary metabolites from S. hydrogenans exhibit the potential to be used as insecticidal agents. In this study, S. hydrogenans extract showed deleterious effects on growth and
development of S. litura larvae that survived the toxic effects of highest concentration. Significant increase in larval development period was observed at all concentrations over the control (P ≤ 0.05). At highest concentration (1600 μg/ml), larval period prolonged by 6.24 days in comparison to control group (Table 1). Our result
coincided with the findings of Arasu et al.  who reported larvicidal and growth inhibitory activities of a novel polyketide metabolite isolated from Streptomyces sp. AP-123 against H. armigera and S. litura. The metabolite also prolonged the larval–pupal duration of the insects at all the tested concentrations as compared to control. The delayed larval period observed in the present study could be due to low consumption Parvulin of diet by the larvae of S. litura indicating the antifeedant effect of the extract. Pupal period decreased significantly with treatment (P ≤ 0.01) however, at highest concentration pupae formed from treated larvae remained in pupal stage till the termination of experiment. The total development period from larva to adult of S. litura differed but remained non significant (Table 1). The LC50 and LC90 values were 1337.384 and 2070.516 μg/ml, respectively for S. litura (Table 2). No larval mortality was observed in lowest concentration as well as in control but when larvae were fed on highest concentrations of 800 and 1600 μg/ml, larval mortality of 20 and 70%, respectively was recorded and was statistically significant compared to control (P ≤ 0.01).