The Environmental Protection Authority has approved a type of parasitic wasp as a biological control agent to combat the tomato potato psyllid (a plant louse), which attacks tomatoes, potatoes, capsicums and tamarillos in New Zealand. Biological control agents are natural enemies of a plant or insect pests, and are released to reduce, control or supress those pests.
The wasp (Tamarixia triozae) will be introduced and released to kill the tomato potato psyllid (Bactericera cockerelli).
The psyllid was first found in New Zealand in 2006 and is known as a pest in several countries, creating a significant impact on plants and crops. The psyllid has three life stages – egg, nymph and adult. Adult females lay eggs on the upper and lower surface of potato, tomato, capsicum and tamarillo plant leaves.
The psyllid nymphs and adults feed on the underside of leaves, leaving the plant stunted and discoloured, with poor or little fruit growth. The psyllid also spreads a bacteria that causes Zebra Chip disease in some crops, like potatoes, which affects crop yields.
The wasp is a psyllid parasitoid which means it attaches to or within a single host, eventually killing it. It is a black, winged red-eyed wasp normally found in North America and Mexico. The wasp lays its eggs on the surface of the psyllid nymphs. The eggs develop into larvae that feed on the nymphs, killing them.
The parasitic wasp will be introduced as part of a pest management programme, in combination with other beneficial insects and chemical control strategies.
The application to introduce the wasp was made by Horticulture New Zealand Inc on behalf of a number of growers’ industry groups under the Hazardous Substances and New Organisms Act 1996.
The EPA received 36 submissions on the application, 32 of them in support, two neither supporting nor opposing, and two opposed.