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Myth: You can identify "brown recluse" spiders by a violin shape.
Most spiders have 8 eyes in 2 rows like Tegenaria, right. Brown recluses (left) and about 430 other spiders (less than 1% of all spiders) have 6 eyes in 3 pairs. Note: front views. Other eye arrangements exist. |
Fact: Because of this myth, brown recluses are
also called "violin" or "fiddleback" spiders. Although the
"fiddle mark" does exist (not always very fiddle-like), it is worthless
in identification!
Many spiders, in assorted families, including the real Loxosceles reclusa,
have a vaguely violin-like spot right behind the eyes. The number of species
with such a spot, by itself would limit this spot's usefulness for identification!
But most people who have heard this myth forget about the "right behind
the eyes" part, and identify as "brown recluses" any spider
in which any part of the body or pattern can be envisioned as violin-shaped.
That includes the vast majority of all spiders! I have seen every common house
spider in my region (where the real thing does not occur) misidentified in this
way.
The spider family (Sicariidae) to which the recluse group belongs is recognized
partly by the arrangement of the eyes, which would rule out 99% of the specimens
that get misidentified -- if anyone ever bothered to look for anything but that
mythical "violin"! At species level, as in other spiders, a powerful
microscope is needed to identify recluses, and in females, it is even necessary
to cut open the abdomen and examine internal parts!
And yet every first-aid manual, every public-health bulletin, every book and
pamphlet on outdoor safety that deals with spiders lets readers believe that
you can recognize this extremely hard-to-identify spider by that absurd "violin"
shape. It is one of the most widely disseminated bits of spider misinformation,
and I'm convinced that health care professionals learn it in medical school
too!
And of course, every place you find the "violin" myth, you'll also
fail to find any suggestion that the spider occurs only in a limited
region -- thousands of miles away from where most of the fearful readers
live!
All equally worthless: assorted "Brown Recluse ID drawings" from newspapers and public agency bulletins. They don't even look like the same species, do they? I think the funniest is "Mr. (really Ms.) Peanut," lower left. Even the most accurate looks just as much like many harmless spiders, as it looks like a recluse! |
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to Spider Myths author, Rod Crawford This page last updated 2 September, 2010 This site best viewed at 800 x 600 using IE 5.0 or above. |