New Zealand is home to a variety of spider species, both native and introduced. While many of these arachnids are harmless to humans, a few possess venom that can be medically significant. Understanding the diversity of spiders in New Zealand, particularly those of concern, can help in safely coexisting with them. This overview clarifies the types of spiders found across the country.
New Zealand’s Spider Diversity
New Zealand boasts an estimated 2,000 spider species, with over 1,100 scientifically described. Over 90% of these species are endemic, meaning they are unique to New Zealand. The remaining approximately 70 non-endemic species have arrived, often inadvertently, through human activities or natural processes like ballooning. Most of these spiders are small, reclusive, and pose no threat to humans. Many play an important role in the ecosystem by controlling insect populations.
Spiders of Medical Concern
Among New Zealand’s diverse spider population, only a few species are considered medically significant due to their venom. The Katipō spider (Latrodectus katipo) is one such native species, found along coastal areas in sand dunes or under driftwood. The female Katipō is dark brown to jet black with a distinctive red stripe running down her back. Bites are rare and usually occur when the spider feels threatened.
Another spider of medical concern is the Redback spider (Latrodectus hasselti), an introduced species from Australia. Redbacks are dark brown to jet black with a prominent red stripe on their back and a red hourglass mark on their underside. They are often found in sheltered urban environments, such as around houses, and their bites are also uncommon.
Symptoms from both Katipō and Redback bites can include localized pain, sweating around the bite site, nausea, and abdominal pain. While rarely fatal, medical attention is advised if a bite from either of these spiders is suspected. An effective antivenom is available for both Katipō and Redback bites.
The White-tailed spider (Lampona cylindrata and Lampona murina), an introduced species from Australia, is dark grey to black with a distinctive white patch at the end of its abdomen. While their bites can be painful, current evidence suggests their venom does not cause skin damage or ulcers in human exposures. Simple first aid is sufficient for White-tailed spider bites.
Common and Harmless Spiders
Many spiders encountered in New Zealand homes and gardens are harmless to humans. Daddy long-legs spiders (Pholcus phalangioides), identifiable by their small bodies and long, thin legs, are common house dwellers. They build messy, irregular webs in sheltered areas and primarily feed on small insects, including other spiders, making them beneficial for pest control. Despite common myths, their venom is not considered dangerous to humans.
Orb-weaver spiders, such as the common garden orb-weaver (Eriophora pustulosa), are seen outdoors. These spiders construct large, intricate circular webs to catch flying insects, often at night. They are not aggressive and pose no threat to people.
Jumping spiders (Salticidae family), including the black-headed jumping spider (Trite planiceps), are small, active hunters with excellent eyesight. They do not build webs for catching prey but instead stalk and pounce. These spiders are harmless and often found in gardens and sometimes inside homes.
The grey house spider (Badumna longinqua) and black house spider (Badumna insignis), introduced from Australia, are among the most common spiders found in and around New Zealand homes. They build dense, funnel-shaped webs in corners and crevices. While their bites can be painful, these spiders are timid and their venom is not considered medically dangerous. They contribute to insect control around properties.
Living Safely with Spiders
Coexisting with spiders in New Zealand involves understanding their behavior and taking precautions. Spiders are shy and will only bite defensively if they feel trapped or threatened. To minimize unwanted encounters, clear clutter in and around the home, as this reduces potential hiding spots. Sealing gaps around windows and doors also helps prevent spiders from entering living spaces. When handling items stored in sheds, garages, or outdoor areas, shaking out shoes and clothing before use dislodges any spiders seeking shelter.
In the rare event of a suspected spider bite from a potentially dangerous species like a Katipō or Redback, seek urgent medical attention. While awaiting medical help, clean the bite area with antiseptic or warm soapy water, and apply an ice pack (wrapped in cloth, not directly on the skin) to reduce pain and swelling. For bites from harmless spiders, simple first aid, such as cleaning the wound and applying ice, is sufficient. If a bite area becomes red, painful, blisters, appears infected, forms an ulcer, or if systemic symptoms develop, consult a healthcare provider or the National Poisons Centre.