Larvorid is an effective biological larvicide /fungicide based on Bacillus thuringiensis – Kurstakii. Bacillus thuringinesis – Kurstakii is extensively used to control moth and butterfly (Lepidoptera) pests.

Bacillus thuringinesis – Kurstakii acts on host larvae through its parasporal crystal containing Delta endotoxin and bacterial spores causing starvation, paralysis and septicemia of larval bodies ultimately resulting in death of larva. The endotoxin acts on midgut epithelium causing disintegration of gut wall, cessation of feeding activity, starvation and leakage of gut contents into haemolymph and body cavity of the larvae leading to general paralysis of larval body. The spores germinate to form bacterial cells that multiply in the larval gut and body causing septicemia.