It was a case of biosecurity know-how at the right place at the right time when two Ruawai lads took an unusual spider along to the Northland Field Days.
They had a female redback spider, seen first by their mother while she was gardening.
The youths scooped up the poisonous Australian invader and took it to the Northland Regional Council marquee at the field days earlier this month for identification.
NRC biosecurity manager Don McKenzie said interesting finds are often brought in during the field days but this was one of the more interesting ones.
While still uncommon, redbacks are here to stay and are endemic in some parts of New Zealand.
There have been sightings in Pahi, Paparoa, Ruawai and Whangarei in recent times, Mr McKenzie said. The latest was at Paparoa last December.
"We do know that they're here in Northland and it's timely to remind people to be a little more diligent in the garden and other outdoor areas," Mr McKenzie said.
The shy spiders posed a low risk but doctors and emergency services needed to be aware that people could present with a new kind of insect bite, he said.
Bites could be extremely painful but, despite the spiders' reputation, no deaths had been attributed to a redback bite anywhere in Australasia since the development of an anti-venom more than 50 years ago. That anti-venom is held at Northland hospitals.
The larger female spiders - their bodies the size of a large pea, black with a red mark on the back and underneath - were responsible for almost all cases of known redback bites.
The redback is the closest relative and looks very similar to the endangered New Zealand native spider, the katipo.
Mr McKenzie said the redback also had an hourglass shaped red mark on its underside.
While the katipo lived predominantly in coastal areas, in grasses and under driftwood, the redback is also likely to be found lurking in urban and rural yards, old buildings, crates and rubbish piles.
While native to the dry island continent across the Tasman, it appears to have adapted to colder, wetter conditions in New Zealand.
There is some evidence of cross-breeding between the redback and the native katipo.
Redbacks were first found in New Zealand in 1980 in Wanaka and New Plymouth, and are believed to have come ashore from cargo ships.