The pipfruit industry has begun a five-year project to find new and more effective ways to control bronze beetle.

The native beetle chews through growing fruitlets leaving apples unsuitable for harvesting and eating.

Apples and Pears New Zealand is investing $598,370 into a five-year project to develop and trial new biocontrol products and to evaluate the effectiveness of a lure to attract and trap females through the use of male pheromones.

It is being backed by $888,630 of funding from the Ministry for Primary Industries Sustainable Food and Fibre Futures Fund.

Apples and Pears research and development manager Rachel Kilmister said bronze beetle is more of an issue for organic growers because they have limited options for controlling it.

“Organic growers cultivate the soil to control the bugs, that disrupts the larvae and prevents the beetle appearing during spring.

“They do about 11 or 12 cultivation passes during October and November, it does provide a level of control but not enough and it’s not sustainable because long-term cultivation isn’t good for the tree or the soil health.”

Kilmister said that bronze beetle is damaging more than 25% of the crop in organic orchards.

“So it’s really costly, and it costs about $13,000 a hectare each year to control it which adds up to $9 million a year for the organic sector, that’s a lot compared to other pests and diseases.”

Kilmister said they want to develop a trap to help monitor populations of the pest and come up with new bio-control options.

“We’ll do things like test pesticides that are available in New Zealand and internationally that we can either apply to the soil or the tree, we’re also looking at whether we can plant endophyte grasses in the soil around the apple orchard and how they might work.

“We’re hoping they’d emit natural chemicals into the soil which would affect the bronze beetle larvae and prevent them from coming up at springtime.”

Kilmister said growers are really interested in the project and keen to trial traps and new controls on their orchards.

- RNZ