Biosecurity experts are tightening their grip on Auckland's fruit and vegetables, after another fruit fly was found.

This one was trapped in Northcote, within the Ministry of Primary Industries' controlled zones.

Restrictions were supposed to be loosened this weekend, but the new discovery means the tight rules will stay in place another week.

Experts are confident they're taking control of the situation regardless, and say more than five tonnes of waste has been destroyed.

There are 5243 fruit fly traps in Auckland, which have all been checked, including more than 600 in controlled areas that are being checked every day or every third day.

A new map of the extended control area can be found at biosecurity.govt.nz/fruitfly.

Movement of fruit and vegetables has been restricted in Devonport since the discovery of a single male Queensland fruit in early February.

The fruit fly is a serious threat to our horticulture industry.

Newshub.