Worldwide distribution. Common parasitising diamondback moth (DBM) in the hot lowland tropics and sub-tropics. Female lays 200 eggs, one in each young DBM caterpillars.
Cotesia larvae eat DBM caterpillar from inside, emerges from the caterpillar and makes a cocoon on the brassica leaf. Look for white, oval pupa. The adult wasp (2-3.5 mm long) hatches after about 7 days and feeds on nectar.
Cotesia cannot prevent damage by DBM alone. IPM programs avoid pyrethroids and organophosphates (these kill Cotesia and predators) and recommend use of Bt (Bacillus thuringiensis).
Monitor and only use Bt when needed; rotate this with other insecticides to prevent resistance to Bt developing.