Dozens of stink bugs have managed to get into the country in a pair of shoes bought on an American website.
Up to 26 live brown marmorated stink bugs, also known as BMSB, were recently discovered in a box of imported shoes in Oamaru.
The information was released by officials from the Environmental Protection Authority in a select committee yesterday.
"The shoes were purchased from eBay and easily slipped through the border," said National biosecurity spokesman Nathan Guy.
"Fortunately, the purchaser did the right thing - contained them and alerted MPI's hotline."
Information on the MPI website dubbed the stink bug a "sneaky pest'' that had been caught on the border numerous times, hitchhiking on passengers coming into the country and in imported goods.
"These bugs could be a damaging economic pest and a significant household nuisance,'' the site says.
"Known to feed heavily on a wide variety of plant species, stink bugs would attack grapes, kiwifruit, apples, citrus and stone fruit, corn and many other valuable crops."
Guy said the risk of a "significant'' BMSB incursion was now an everyday risk via the mail pathway; particularly with people purchasing items via overseas websites.
"I worry how many stink bugs are already driving around New Zealand in imported cars waiting to multiply and devastate our fruit crops.
"The cost of a stink bug outbreak could reach $4 billion and would be catastrophic for our horticulture industry."