Stink bugs have stopped traffic at some of New Zealand’s biggest ports – causing a big back-log of car imports after changes to the country’s biosecurity protocols.

On Monday, three ships carrying new cars were ordered out of NZ waters — and a fourth voluntarily diverted because of the bug – leaving 6000 vehicles at sea.

As many as seven ships have been affected, all of which were from Asia, particularly Japan.

But the big stink is good news for NZ’s largest second-hand car dealer, Turners Automotive Group (ASX:TRA), which says it has plenty of cars to fill the void.

“Turners is benefitting in the short term, as its wholesale auction channel provides an alternative supply option,” it said.

“Customers are also turning to larger retailers as their first point of call as they trust them to have a large supply of stock available.”

Shares in the company last traded at $3.

Under new rules from the NZ Ministry of Primary Industries, 20 per cent of cargo on incoming ships must be heat-treated before ships are given the all clear to unload – a move to make sure no foreign creepy crawlies make their way into NZ’s horticultural crops.

It says, if established in the country, the humble stink bug could cost the NZ export market $4.2 billion by 2038.

Turners said while it did have imported vehicles held up in the stink, the impact was only minimal.

“Getting an effective solution on the supplier side has to be a critical part of the solution.

“Pleasingly, many of our Japanese suppliers have already starting taking preventative actions to ensure stock is fumigated and bug-free before being loaded into ships.”