Ask the Naturalist

Ask the Naturalist: Should I Be Afraid Of This Spider?

November 7, 2014
The tengellid spider can often be found in caves. Photo: J. Maughn, Flickr
The long-legged tengellid spider can often be found in caves. Photo: J. Maughn, Flickr

Q: I’ve heard of a very large and scary-looking spider that can be found in the Santa Cruz mountains (pictured above). Is this spider poisonous? Should I fear it if I encounter it in the wild? — a Bay Nature staffer

A: First, let me correct a common misconception for you – Spiders are venomous, not poisonous, which means if you ate one you would be OK, but when they bite you they inject venom into you. In most cases the venom is not strong enough to do any more than give a red, itchy bite which goes away quickly. Some people however, are allergic to spider bites in the same way that people are allergic to bee stings.

So yes, this spider will be venomous as are most spiders. The spider is a male — you can tell from its
longer  pedipalps at  the  front  of its cephalothorax. These look like an extra set of legs and contain its reproductive organs in the tip.

This spider is identfied on flickr as a titiotus sp. – a tengellid spider. These spiders are endemic to California and are often mistaken as the desert recluse. I couldn’t find any common name for them.

Titiotus seems to prefer steep, rocky canyon slopes near high montane streams. At lower elevations, including the Coast Ranges, this species occurs mostly in forests, especially oak and mixed evergreen, but also in rocky grasslands. They’re also strongly cavernicolous; almost half of the known species are recorded in caves, where they may be quite abundant. Their egg sacs are spherical, about 1.5 cm in diameter, with a papery outer covering, and could be found suspended from the ceiling by a thick cord of silk about 1–2 cm long.

— Glen Crew,

>> Read more about the tengellid spider on Glen’s spider website.

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