Invasive venomous spider establishes itself in NZ
Tuesday, 1 July 2025
One of the world’s most invasive spiders has officially established itself in New Zealand - and it has a venomous bite.
The first confirmed sighting of the noble false widow spider, that’s less frighteningly known as Steatoda nobilis, was in November 2024.
Since the initial sighting in Porirua, there have been confirmed sightings in Christchurch, Nelson, Northland and Waikato.
The arachnid appears to thrive in urban environments, particularly around gardens and outdoor furniture and is most often found under plant pots, tarpaulin and in fence crevices. The males are seen at night on exterior walls or the ground.
Professor Steven Trewick, an evolutionary ecologist at Te Kunenga ki Pūrehuroa Massey University, led efforts to verify the spider’s identity.
He compared its physical features and analysed DNA from a sample collected in Porirua by Gavin Picknell.
The spider can bite in self-defence although it is not described as aggressive, but there are concerns according to Trewick.
“Although considered less dangerous than black widows, the venom of Steatoda nobilis contains similar toxins.
“Particularly concerning is its association with antibiotic-resistant bacteria. Infections resulting from bites don’t always respond to treatment, and that’s a significant medical concern.”
Most bites result in mild symptoms such as swelling, redness and pain. However, some have been linked to more serious effects including tissue necrosis, nausea, hypotension, impaired mobility and secondary bacterial infections that may be resistant to standard antibiotics, a Massey University spokesperson said.
The spider was originally from the Canary Islands and Madeira and has become well established in Europe, North and South America, and now New Zealand.
Suspected sightings of this spider can be freely uploaded to the citizen science platform iNaturalist NZ and will help researchers discover the extent of the invasion.
CORRECTION: The spider is venomous. An earlier version of this story incorrectly said it was poisonous. (Amended: July 1, 2025, 12.28pm.)