365 Urban Species. #098: Woodlouse Spider

[urbpan]

Urban species #098: Woodlouse spider Dysdera crocata

While handling this spider trying (unsuccessfully) to get a better photograph, I became unnerved when I noticed its fangs. Usually on a spider this size (maybe 3/4 or an inch, or a little less than 2 cm) the fangs are inconspicuous, tucked away underneath. The woodlouse spider has long, obvious fangs, presumably strong and sharp for piercing the shell of their crustacean prey. Most spiders' fangs are not strong enough to bite through human skin, but some are, and this individual looked capable. But it showed no inclination to bite, instead clambering in a panic to remove itself from the light.

Research after the fact indicates that it indeed could have bitten me, but it wouldn't have injured me seriously. Or to use some delicious technical language: "D. crocata bites have been implicated in causing a localized, intensely pruritic rash with coalescing dermal papules 4-5 mm in diameter.  The bites apparently do not result in any systemic neurotoxicity or cytotoxicity." (http://www.ento.psu.edu/extension/factsheets/Spider/spiders.htm)

The woodlouse spider, unsurprisingly, is found anywhere woodlice are. Under logs and stones and other debris near buildings is where you will most likely encounter one. They were apparently introduced to North America and Australia, along with their favored prey, from Europe. It's possible that no introduced woodlice are considered invasive because their predator comes along with them when they travel.

Comments

woodlouse spider

[trenee2001mi.livejournal.com]

I live in southern CO and one of these crawled across my bedroom carpet a few days ago. After researching online, I believe it was a female, and sources indicate it probably mated and laid eggs in April. How do I find them? I couldn't breath with just ONE near me!

Re: woodlouse spider

[urbpan.livejournal.com]

According to this site, http://www.spiders.us/species/dysdera-crocata/ the female guards the egg sac "in her silken retreat." So wherever she hides during the day, that's where the egg sac is. The good news is that all the eggs are in one place.

Re: woodlouse spider

[trenee2001mi.livejournal.com]

how do I figure out where she hid it? Under dressers, bed, inside heater vents? I just don't know how a spider this huge got into my room!

Re: woodlouse spider

[urbpan.livejournal.com]

I'd check areas where something from outside could get in, or things from the basement could come up: windowsills, radiators, corners, behind doors etc.