'Potentially sinister' spider spreads into South Island

The noble false widow spider has officially established itself in New Zealand. Photo: Massey University

Researchers are warning about the spread of a venomous spider with a "potentially sinister bite" which has officially established itself in New Zealand.

The noble false widow spider has been sighted in Christchurch and Nelson after first being seen in Wellington last December.

Professor Steven Trewick, an evolutionary ecologist at Te Kunenga ki Pūrehuroa Massey University, said the spider was not aggressive but may bite in self-defence.

"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."

The invasive arachnid has been dubbed 'Britain's most dangerous spider' after a bite left a man struggling to walk.

Prof Trewick led efforts to confirm the spider’s identity by comparing its physical features and analysing DNA from a sample collected in Porirua.

Since the initial Porirua sighting, the spider has also been confirmed in Christchurch, Nelson, Northland and Waikato.

"It appears to be thriving in urban environments, particularly around gardens and outdoor furniture.

"It is most often found under plant pots, tarpaulin and in fence crevices, while males are seen at night on exterior walls or the ground."

Although considered less dangerous than black widows, the venom of the noble false widow (

Steatoda nobilis

) contained 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,” Professor Trewick said.

Pest Management Association of New Zealand executive councillor Vicki Smith is yet to encounter the spider in the South Island.

However, if it made its way even further south, they are well equipped to deal with it, she said.

"It’d be easy.

"It’s only like dealing with the white-tails."

Ms Smith pointed to another invasive species that appears to be making its way south, which could soon pop up in Dunedin.

Although there had not been any reports of the Argentine ant south of Timaru, it was on its way, Ms Smith warned.

Originally from the Canary Islands and Madeira, the spider has become well established in Europe, North and South America and now New Zealand.

While the full impact of this spider on native wildlife was yet to be fully understood, Professor Trewick says its arrival reflected broader global patterns.

“This is part of a wider pattern of biodiversity loss and rapid environmental change. Invasive species like this one highlight how globalisation and climate shifts are reshaping our ecosystems, often at the expense of native wildlife.”

Suspected sightings of this spider can be freely uploaded to

iNaturalist NZ

and help researchers discover the extent of the invasion.

- APL