Abstract: The insecticidal strain 173 was isolated from marine source and its
activity was explored by the bioassay of brine shrimp and Helicoverpa armigera.
Based on morphological, physiological and molecular properties, the
insecticidal strain 173 was identified as Streptonycetes avermitilis, which is
the best insecticidal microorganism found in the terrestrial environment. The
taxonomy of the strain 173, insecticidal spectrum and properties of the
corresponding insecticidal antibiotics are reported.