WAIKATO NEWS

Moth pest fall armyworm found in Hamilton, growers asked to watch for pest

29 Apr, 2022 05:20 PM2 minutes to read

Biosecurity New Zealand and primary sector partners are asking maize and corn growers to keep an eye out for the moth pest fall armyworm. Photo / Crop Science Australia, Ted C. Macrae

Waikato Herald

The moth pest fall armyworm has been discovered at two properties on the outskirts of Hamilton so Biosecurity New Zealand and primary sector partners are asking Waikato maize and corn growers to keep an eye out and report any signs of caterpillars on their plants.

The fall armyworm is a plant pest that can cause damage to crops. It is native to the Americas and can feed on more than 350 plant species, including corn, beans, capsicum, onions, kumara and tomatoes.

The moth’s larvae particularly feed on stems and leaves which causes crop damage. They can skeletonise the leaves and severe infestation can cause unwanted defoliation.

On corn, larvae attack the ear, silks, cob and kernels which reduces leaf mass, fruit, pods, seeds and the overall plant health.

Adult moths are between 16 and 18mm long, and have a wingspan of 38mm. The forewings are a brown-grey colour and the hind wings a cream colour.

Larvae change from a green-brown to a brown-black colour as they mature and are almost black in the “armyworm” phase. Eggs are only about 0.4mm and laid on leaf surfaces in masses of between 150 and 200, covered with a protective layer of scales.

The fall armyworm was introduced to Africa, Asia and parts of Australia in 2016, but because it usually thrives in very warm climates, it was thought unlikely the pest would spread into colder climate zones like New Zealand. However, in March this year, egg mass belonging to the moth was found in Tauranga.