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

[urbpan.livejournal.com]

I can't seem to determine this. I personally have found three over the past few years. I'd guess: "Less common than jumping spiders Phiddipus audax and cellar spiders , but more common than black widows and brown recluse spiders (neither of which I've ever seen in New England (yet?))

[artemii.livejournal.com]

hmm. i'm not sure if i've ever seen one or not; it's hard for me to tell from the lone picture (i guess i should do a web search for more photos). i saw so many spiders in my old garden -- tons of jumping spiders, as well as a fair number of funnel-weavers, several goldenrod spiders, some crab spiders, and other kinds. i also saw a fair number of mites and mite relatives. but i don't know if i've ever seen this species in metro boston.