Hosts of the diamondback moth are buk choy, cabbage and other cruciferous vegetables.
Larvae feed on the leaves, stems, flowers and seed pods. Damage is seen as holes in the leaves, or ‘windows’ (‘see-through’ leaf with an unbroken upper leaf layer) where larvae have tunnelled into the leaf. When infestations are high, leaves may be skeletonised.
Eggs: Pale yellow, flattened and ovalshaped, and 0.5 mm in length.
Immatures: Larvae are pale-green or grey-green with a dark head and a darker green stripe running down the body. They are up to 12 mm in length.
Adults: Grey-brown with a white diamond-like pattern along the back where the folded wings meet (viewed when the adult is at rest). Adults are 10 to 12 mm in length.