An offensive is underway to eradicate the Great White Butterfly.
The pest, which was found in Nelson in 2010, is known for feasting on brassica crops like broccoli, lettuce, and cabbage.
Farmers are being called on to report any signs of the butterfly's yellow spotted caterpillar.
Federated Farmers biosecurity spokesperson Dr William Rolleston says Great White Butterflies have the potential to decimate large plantations.
Anyone who finds an infestation is asked to contact the Ministry for Primary Industries.