white-tailed spider hunting other spiders in their own webs
- Size
- Body: 1–2 cm
- Lifespan
- 1–2 years
- Diet
- Predatory: feeds primarily on other spiders, including house spiders and grey house spiders. Active nocturnal hunter that does not build a web. Mimics struggling prey to lure resident spiders close before attacking.
- Habitat
- Preferring the lifestyle block of the invertebrate world, usually found under dry bark, rocks and leaf litter. Has a notorious penchant for the indoor-outdoor flow of human bedrooms, often seeking shelter in dark folds of laundry left on the floor.
- Range
- Throughout North Island and northern South Island in homes, gardens and natural habitats. Most common in urban and suburban areas where spider prey is abundant. First recorded in Auckland in 1886.
- Endemism
- Introduced
- Main Threats
- None. This introduced species is widespread and common. Faces no threats and is often found in homes where spider prey is abundant. Populations are secure and may be expanding range southwards.
- Population
- First recorded in Auckland in 1886, now successfully spread across North Island. Numbers peak in warmer months when common house spiders are most plentiful.
- Conservation Status
- Introduced
The bounty hunter of the New Zealand arachnid world. The white-tailed spider ditched web-building entirely in favour of something more direct: active pursuit. Its sleek, cigar-shaped abdomen tipped with a white patch is built for a life on the move, hunting at night, covering ground, looking for other spiders to eat.
The tactics are good. It will walk into another spider's web and vibrate the silk to mimic a struggling insect. The resident spider comes out to investigate. That is a mistake. White-tails target other introduced species - black tunnelwebs, daddy-long-legs - which makes them a strange kind of accidental pest control. The ecosystem doesn't particularly care either way.
In late summer the males range further, looking for females. The females tuck silk egg sacs into cracks and dark folds of fabric - which is how the spider ends up in the towel, the shoe, the sleeve left on the floor. It is not aggressive. It bites when compressed against skin, which happens more often than anyone plans for.
The bite itself is where things get complicated. The necrotic wound story - flesh rotting away, hospital stays, amputations - was largely a media event of the early 2000s, and the science never fully supported the most extreme claims. But "media exaggeration" is not the same as "harmless." Reactions vary considerably. Some bites produce little more than localised redness. Others cause significant swelling, pain, and secondary infection that persists for weeks. The mechanism is not fully understood. People have ended up in hospital. The bite deserves to be taken seriously.
It is not the monster it was made out to be. It is also not nothing.