The Brown Widow Spider -- What You Need to Know
What is the Brown Widow Spider?
You've probably heard of the black widow spider, and you probably know that the bite from one of these spiders can kill you. The brown widow spider, Latrodectus geometricus, is an arachnid closely related to the deadly black widow, Latrodectus macrons. And the brown widow is showing up in places where no one expects.
The brown widow's range was previously limited to the southeastern United States, but in recent years it has been turning up in the western states as well. In these areas, it may be replacing the black widow as the predominant widow species. The reason this matters is that brown widows are more inclined to spin their webs in places humans congregate, especially under outdoor furniture and around barbecues. And while the bite if the brown widow won't kill you, it's still in the Latrodectus genus, meaning its venom affects humans and other mammals. So while the bite of the brown widow is somewhat less toxic than the black widow, both spiders are known to be poisonous. Like other stinging or poisonous insects, the brown widow is more of a nuisance than a life-or-death situation. But you still want to avoid it!
Is The Brown Widow Poisonous?
The short answer is "yes." But it's not as poisonous as the black widow spider, to which it is closely related, and reported bites are less severe. Brown widows are also less aggressive and more likely to retreat and guard their eggs. Still, if you have a large number of brown widow nests around your house, especially in high-traffic areas like yard furniture and kids' toys, then you should take steps to control them. There's always a chance that someone may put their hand into a dark corner and come away with a bite.
Brown Widows on Children's Toys? Yikes!
Yes, that is a bad situation, and if you have large outdoor toys that haven't been used in a while, and you live in California or Florida, you'd be well advised to check them top to bottom for lurking brown widows. A simply spray-down with a hose will clear out all kinds of spiders and bugs, including brown widows and other spiders. These arachnids are not aggressive and will typically try to run or hide when disturbed in their webs, but it's better to be safe than sorry. A good spray or cleaning also reduces the chance that other unwelcome spiders and insects, including wasps, may have taken up residence in your toys or outside furniture.
Brown Widows Also Like Porch Furniture
The Brown Widow Spider in California
The brown widow spider is a poisonous species currently replacing the black widow as the most common "widow" species in California and other parts of the country.
According to a recent article in The Journal of Medical Entomology, the brown widow spider's California population explosion may result in the displacement of the more-familiar black widow. The brown widow was first discovered in Florida in 1935. It turned up in California in 2003, a startling range expansion that suggests the spider is thriving in the recent warm weather. Recent searches for black widow spiders turned up more brown widows than black widows, leading researchers to suspect that the black widow may be on the run. The implications for humans are unclear, but this may be one more example of climate change altering the distribution of species.
Brown Widow Spider Identification Guide
How To Identify the Brown Widow
The brown widow is a medium to large spider with various shades of brown on its body. There is s general striped pattern on the dorsal (top) side, and brown mottling on the ventral side. It often has red markings on the ventral side, although this is a less reliable characteristic than the bright red hourglass mark typical of the black widow. Like all spiders, the brown widow has eight legs. Widow spiders spin tangled, sprawling webs in dark corners and under lawn furniture.
Researchers Surprised by Brown Widow Surge
According to researcher Richard Vetter of the University of California Riverside, the brown widow was found in surprisingly large numbers during an assessment of the population of the more familiar black widow spider. What surprised researchers most was the fact that the brown widow had begun replacing the black widow in many places. In addition, the brown widow tends to live in areas where human contact is more likely -- under lawn furniture, for example. And even though it is less toxic than the black widow, the brown widow and virtually all Latrodectus species of spider have potent venom.
What Happens when a Brown Widow and a Black Widow Meet?
Black Widow Showing the Red Hourglass
The Brown Widow Versus the Black Widow
Compared to the poisonous black widow, the brown widow is less distinctly marked. The black widow is typically black or very dark brown, with a sharply-defined red hourglass or similar marking on the underside. The brown widow's coloring is less sharp and clear, though there is usually a red shape on the underside. The poison of the black widow is more toxic to humans, though the brown widow, like all spiders, is poisonous to an extent. In terms of habitat, the brown widow likes to spin its tangled, "messy" web under ledges and in crevices, though it will set up shop in areas where humans are present, such as garages, back patios, and so on.
Can You Pass This Brown Widow Spider Quiz?
What To Do If You Are Worried About a Brown Widow Spider Infestation
First, you need to make sure you actually have a problem -- if you live in California, check under your outdoor furniture, inside hiding places like buckets and flowerpots, and in the corners of your garage, high and low. You will see a lot of spiders, but NOT EVERY BROWN SPIDER YOU SEE IS A BROWN WIDOW! I can't emphasize this enough -- spiders in general are very good to have around, and if you kill all the spiders you find, the only thing you'll accomplish is increasing the number of flies and mosquitoes and cockroaches around your house. Spiders eat bad bugs, so spiders are really good bugs!
If you find an animal you think is a brown widow, take a few good pictures of it -- with flash! -- and post it to one of the many insect sites on the web. Some extermination sites have quality pest identification guides that provide photos for you to compare your spider to. If you're really adventurous, you can try to capture a specimen of the spider -- living or dead -- and take it or send it to a museum or agricultural extension office. They'll be able to tell you what you're dealing with, and you'll also be doing your community a favor by alerting it to the presence of the spider.
Sticky Traps Are Affordable and Effective
Spiders in a Sticky Trap
Brown Widow Vs Ants
If You're Sure It's a Brown Widow...
If you are SURE it's a dangerous spider, ask yourself -- can we just live and let live? Brown widow spiders stay in their webs, so if it's in an out-of-the-way corner, you should probably leave it be. But if you're truly worried that you or a loved one might come into contact with the spider, then you may use a commercial insecticide (a little web research will help you choose). A quick spray will kill the spider. DO NOT just spray the stuff around your property! The only insects you'll really hurt are the ones who eat the bad bugs for you.
If you find a LOT of brown widow spiders around your house, then it's probably time to call a professional. Again, web resources are very helpful for finding help with your spider problem.
More by this Author
Hornworm caterpillars eat the leaves and fruit of tomato plants in your garden. Here's how to identify them and keep them from eating all of your tomato harvest.
What are the most painful stings in the world? Here's everything you need to know about the top ten most painful stings on earth.