Pest wasps are costing New Zealand's economy $130 million a year, a new study says.
The impact of the introduced pests included wasp-related traffic incidents, costing $1.4 million a year, and more than $1 million in health costs from wasp stings.
But the greatest impact was on farming, beekeeping, horticulture and forestry, the study said.
Wasps disrupted bee pollination, reducing the amount of clover in pastures, and increasing the need for fertiliser, costing the farming industry $60 million a year.
The cost to beekeepers of stopping wasps from attacking honey bees was $9 million a year.