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The Spider Myths Site
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Myths about Identifying Spiders

Myth: I found a photo of a spider species that looks just like the spiders in my house, so now I know what they are.

Fact: In other words, you have one color picture of one species of spider, and this magically enables you to tell how that species differs from hundreds of others of which you do not have pictures? Sorry, but it doesn't work that way.

In the first place, as noted elsewhere, naked-eye appearance is more deceptive than useful, in spider identification, to anyone but an experienced specialist. Furthermore, the appearance of one specimen of one species will give you no information on the differences between that species and similar ones, and no idea of how variable the species in question might be.

The geographic range of the species must also be considered. Even if your spider from Texas "looks just like" a photo from Belgium, the chances are that you have not made a correct identification.

No spider can be considered reliably identified unless a spider specialist has examined it under a microscope. Not even if it's identical to that photo you found, right down to the very last spot!


Myth: Physicians, exterminators, and entomologists can identify spiders.

Fact: Only arachnologists have the highly specialized skills needed to identify spiders, which take years of concentrated study to learn. To be sure, a few entomologists (insect specialists) and a very small number of physicians are also arachnologists, but the vast majority are not.

No medical school teaches even the basics of real spider identification; the most that medical students are likely to get is misinformation about identification by so-called "markings." Sad to say, numerous physicians have mis-diagnosed patients with mysterious sores, without even seeing a spider, as having been bitten by spider species which did not even exist in their locations.

Most pest control operators have very inadequate training even in the identification of common pest insects; few are trained entomologists, and I know of only one in the United States who is an arachnologist. Misidentifications by non-arachnologists are the source of a very large number of false spider reports and "scares" in the news media.

Text © 2003, Burke Museum of Natural History & Culture,
University of Washington, Box 353010, Seattle, WA 98195, USA
Phone: 206-543-5590
Photos © as credited
Queries to Spider Myths author, Rod Crawford

This page last updated 2 September, 2010

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