Home > Health Library > Black Widow Spider
Black widow spiders (Latrodectus mactans) are found throughout the Western Hemisphere. A female black
widow is much more likely to deliver more venom than a male spider.
Female black widows are long-legged, shiny, coal-black spiders with an
orange, red, or yellow hourglass shape on the underside. The female black widow
is usually about
1.5 in. (3.8 cm) long, but it may
Black widow spiders tend to
bite defensively when their webs are disturbed. Black widow spiders are
frequently found in low-lying webs in garages, barbecue grills, around swimming
pools, and in wood piles. Bites to babies and children may be more serious than
bites to adults. Signs and symptoms of a black widow bite include:
In some cases, severe symptoms appear within 30 to 60
minutes. These include:
A doctor should be contacted immediately when a person is
bitten by a black widow spider.
Current as of:
May 27, 2016
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine
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