The katipō (Latrodectus katipo) and the redback spider (Latrodectus hasselti) are the only venomous spiders found in New Zealand. Only the adult females are capable of biting humans. Bites from both species are extremely rare, and there is a safe and effective anti-venom available.
The white-tailed spider (Lampona murina and Lampona cylindrata) is more common, and is often found in human habitats, including on the walls and ceilings of residential homes. White-tailed spiders will bite if provoked but in most cases the bite will cause little harm. The white-tailed spider bite can be painful, with some initial swelling, redness, itchiness and a burning feeling at the bite site. These symptoms will go and there are no long-lasting effects. White-tailed spider bites are not considered poisonous to humans. A recent Australian study has shown no evidence linking necrotic ulcers (destroyed skin) to white-tailed spider bites.