By 3 News online staff
New Zealand First is calling for an inquiry into the Ministry for Primary Industries after venomous spiders were found in two consignments of Mexican table grapes that made it to supermarket shelves.
The fruit has been taken off New Zealand shelves because 10 spiders, including five black widows, a suspected brown widow and two likely yellow sac spiders were found amongst the grapes.
The MPI says work is underway to identify the remaining arachnids.
NZ First primary industries spokesman Richard Prosser says the Auditor-General should be called in to investigate the department, and wants an end to the "honesty box biosecurity".
"I cannot believe imported, high-risk fruit and vegetables is based solely on a visual inspection."
The party is writing to the Auditor-General to ask for an investigation into the performance as MPI as a regulator and enforcer.
Foodstuffs, which owns Pak 'n Save and New World supermarkets, says it has taken all red, green and black grapes its shelves.
It has also asked importers of Mexican products to prove their goods have been fumigated.
Competitor Progressive Enterprises, which has the Countdown chain of supermarkets, says it has taken all Mexican grapes from the shelves of South Island stores.
However, none of the North Island stores received any grapes from the affected shipments.
MPI is working with retailers to ensure any spiders that may have entered New Zealand are identified and destroyed.
The department's surveillance manager Brendan Gould says there are strict controls over the importation of grapes from Mexico and other countries.
"In the case of Mexico, grapes are visually inspected and if spiders or other pests are identified, there is a requirement for fumigation.
"We take this matter very seriously and we are investigating how this breach has occurred and taking measures to tighten up the system."
Those importing the grapes which are in transit are being given the option of treating or destroying them on arrival in New Zealand.
MPI believes the spiders aren't a threat to New Zealand's horticulture industry, but they could be to people who come in contact with them, though they don't normally bite unless disturbed.
A spokesperson says the spiders aren't generally considered as being a serious danger to humans, although the effects could be felt more heavily for the very young or those with weakened immune systems.
MPI is asking those who find a spider amongst Mexican table grapes they've already bought bag the fruit and the spiders, seal them and to call the exotic pest hotline on 0800 80 99 66.
Anyone who thinks they've been bitten by a spider should contact their doctor and information is also available by calling the Ministry of Health's Healthline on 0800 611 116.
Mexico's exporting season for grapes has now finished for the year.