Spider eggs, no – but do watch out for these crawlers

If a viral BBC story this week about a spider that laid eggs in a man’s toe had your skin crawling, fear not – we can still go barefoot, as top NZ spider experts have debunked the yarn as an “urban myth”.

The BBC has since amended the story about an apparent wolf spider bite on a UK man in France on its website but it remains in its original format online in other news outlets.

We have around 27 species of wolf spiders in Aotearoa, says arachnologist Dr Phil Sirvid, resident spider expert at Te Papa museum in Wellington.

But “no spider is capable of what the spider is accused of in the story”, he said. “Spiders just don’t lay their eggs inside people, but there are persistent urban myths about them doing so.”

Spider expert Dr Leilani Walker isn’t buying the yarn either.

“I have no hesitation in saying that this story is incorrect. Are there animals that lay eggs in living tissue? Absolutely. Are any of these spiders? Absolutely not.”

Walker was involved in an international study in which a team of experts analysed more than 5000 stories online about spiders, and found half of them were

incorrect or had errors.

“I am confident in saying that there are no spiders, anywhere, let alone in New Zealand, that will lay eggs in a wound.”

There are only three species of spider in New Zealand considered "medically significant", says Walker: the katipō, the redback and the white tail.

Another of the country’s leading experts on archanids, lecturer in entomology at Lincoln University Cor Vink is sorry that the wolf spider is being “blamed for something it didn’t do”.

He is, though, researching how to control the growing redback population.

The redback, like the katipō, is a widow spider, and both have poisonous venom.

A bite is nasty – and may bring on sweating, breathing difficulties, convulsions and vomiting – but it’s usually not fatal, and can be treated with an antivenom, he said.

Back at Te Papa, Sirvid puts people’s fear of spider bites into context.

“Out of the over 1100 spider species found in New Zealand the katipō and redback have the most medically significant venoms.

“The vagrant spider (a large brown spider found across much of NZ) can reportedly cause joint pain and perspiration and heavy perspiration in some people, while others don’t react at all. White tails are unjustifiably feared, but are to be respected for their mechanically painful bites.”

He agrees the one spider that experts are keeping an eye on is the redback.

“They seem to be increasing in the Central Otago area and are now showing up in places like Cromwell and Alexandra. There have also been reports of a small, persistent population in New Plymouth.”

As redbacks can live around houses, that makes them a riskier proposition than katipō that don’t. We aren’t really in the habit of living with significantly venomous spiders in our backyards.