DELFIN WG is a biological insecticide based on the SA-11 strain of Bacillus thuringiensis (Bt) subspecies kurstaki (Btk) which is a spore-forming bacterium which produces, in addition to spores, crystals of a protein endotoxin. This endotoxin is specifi cally toxic to lepidopteran larvae. DELFIN WG acts within the gut of the target larvae. DELFIN WG causes feeding inhibi tion within a few minutes of ingestion. Eventually disintegration of the gut wall and larval death occur. Dying larvae can be expected to be found for several days after application. DELFIN WG is a selective agent that provides fast and effective control of lepidopteran larvae, without harmful effects on humans, domestic animals, honeybees, wildlife, fi sh and benefi cials. Thorough spray coverage is essential as DELFIN WG is active only if ingested by the caterpillar. Coverage of the underside of the leaf is important.