Citrus imports from the US have been temporarily halted after fruit fly larvae were discovered in a consignment earlier this week.
The larvae of the spotted wing drosophila were found in a single orange during a routine inspection of a consignment on April 8.
“The fly is a serious pest that could harm a range of fruit crops,” said Roger Smith, head of Biosecurity New Zealand.
Smith said the fly is not normally associated with citrus fruit and the ministry’s technical experts are assessing the find and any measures that might need to be taken.
“As a precautionary measure, we have put a temporary hold on citrus consignments from the US,” he said.
“We are working with authorities in the United States to identify the source of the contamination and possible treatment options for consignments on their way to New Zealand.”
Spotted wing drosophila are native to India, Korea, Japan and much of South-East Asia. They are also found across much of North America and Western Europe.
Biosecurity NZ says the flies are a particular risk as they can lay eggs in fresh fruit before it is even picked. They can damage berries, stonefruit and grapes.
“If they invaded New Zealand, all commercial and home growers would face increased pest control costs and lowered crop yields.”