Bt cabbage is developed against

Bt cabbage is developed against Diamond Back Moth.
Cabbage plants transformed with a synthetic Bt gene, cry1Ab3, were all resistant to larvae of the diamondback moth, whereas all plants transgenic for cryIIa3, a wild-type Bt gene, were susceptible.
The diamondback moth is the most destructive insect pest of brassica crops throughout the world. The moth is most active at night. Economic damage is most severe when heading begins. The caterpillars tunnel into the leaves of the forming heads of cabbages.