Fruit growers in New Zealand are on alert after the discovery of a second Queensland fruit fly in as many months.

A second Queensland fruit fly has been found in New Zealand in as many months.

The single fruit fly was discovered in a surveillance trap in Whangarei on Tuesday, about 400 metres from where another fruit fly was found in January.

Heavy restrictions were imposed on Whangarei’s fruit and vegetables in January to protect New Zealand’s horticulture industry, but subsequent trap checks found no evidence of other insects.

The Ministry for Primary Industries (MPI) said Tuesday’s find is not related to the January incident.

“As in January, it is vital we find out if the insect is a solitary find or if there is a wider population in Whangarei,” MPI spokesman Andrew Coleman said.

“This insect is an unwanted and notifiable organism that could have serious consequences for New Zealand’s horticultural industry and home gardeners.

“It can damage a wide range of fruit and vegetables.”

MPI has deployed staff to lay extra traps to ensure no more of the pests have migrated across the Tasman.

Movement of fruit and vegetables in the area will again be restricted.

Fruit fly populations have “dramatically increased” in Australia recently and New Zealand is reviewing importing requirements to goods at risk, Mr Coleman said.

Fruit and vegetables are New Zealand’s fourth-largest export earner at just over $2.5 billion a year.