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Spiders: Fact vs. Fiction

On October 12, 2011 | At 8:54 am

Black widow spiderThere’s a lot of hype out there about spiders.

This summer, I had a bunch of quarter-sized creepy crawly things with eight legs and white marks on their backs scurrying around my house. I just assumed they were black widows. I didn’t get much sleep.

Then a few of my friends in Charlottesville tried to set me straight. I really needed to be concerned about brown recluses, not black widows, they claimed.

I talked to Kristin Wenger, public health educator at UVA’s Blue Ridge Poison Center who keeps a black widow in a jar in her office. It turns out we were all wrong. There are a lot of misconceptions and false sightings of both of these spiders.

To set us straight, Kristin answered some common spider questions.

What dangerous spiders live in Virginia?

The only one is the female black widow spider. The male black widow spider is much smaller and can’t hurt us. Black widows are very common throughout the state.

The female black widow is black and shiny with a bright red hourglass-shaped mark on her large, round abdomen. Sometimes the red mark is orange or yellow. She is not a furry spider. Fully mature black widows can be as big as a silver dollar, including the legs.

Another identification clue is the web: black widow webs are messy and not in any order. The pretty, two-dimensional web like the one in Charlotte’s Web is not a black widow web. The black widow moves extremely fast when it’s in its web, but it has trouble walking on the ground.

Where do black widows live?

If you were a spider, you would want to be somewhere where you and your web would be safe. So black widows live in undisturbed dark places. They love wood piles, sheds, barns, attics, basements, crawl spaces and dark places under your porch.

They also can be in rocky places like rock walls or stone steps.

How common are black widow bites?

Not very, considering how common the spider is. In 2010, there were only 36 calls to our poison center about black widow bites.

The last thing a spider wants to do is bite you, because it needs its venom to get food. It’s not going to waste it unless it’s in danger.

What about the brown recluse? Don’t we have those in Virginia?

The brown recluse spider has become almost a source of urban legend, and it’s led to a lot of paranoia and misdiagnoses. The brown recluse is not native to Virginia. It doesn’t like our climate.

That doesn’t mean that there isn’t the occasional one here or there. Spiders are really good at hiding in your furniture or your suitcase, so when people move, they might bring a spider or two with them.

A lot of little brown spiders look like the black recluse, and a lot of symptoms can mimic a spider bite, including MRSA infection. Even in places where the brown recluse is native, a bite is very uncommon because it’s a very shy spider.

How can you prevent spider bites?

Most bites are accidents and most people never see the spider that bites them. If you’re in an area where you know spiders live:

  • Wear gloves.
  • Watch where you put your hands.
  • Put on a long-sleeved shirt and wear gloves when carrying wood.

Most of the calls that we get about spider bites are between April and October. But last year, during the first snowfall, I found a black widow under a flowerpot outside. The pot had insulated the spider.

What are the symptoms if you’ve been bitten?

People tend to not notice the actual bite, which is not very painful. A couple of hours later, though, they notice the reactions to the venom.

Most spider bites: All spiders inject some kind of venom. Most spiders inject venom that destroys your cells and tissues. So the symptoms are:

  • Painful swelling
  • Redness
  • An oozing blister

There’s really not much you can do for that except keep it clean and go see your doctor if you see signs of infection.

Black widow bite: The black widow is really different, though. Her venom is not that kind of venom. Her venom is a neurotoxin, which means it affects the nervous system. So instead of a wound, symptoms may include:

  • Sweating
  • Headache
  • Nausea
  • Very painful muscle cramping and spasms.

Rarely, there can be heart and breathing complications.

You definitely want to seek medical care because it’s so painful, and the doctor can manage your symptoms. But the spider bite is very survivable. People almost never die from black widow spiders.

There is an antivenin, but there are a lot of risks associated with it. The poison center can help nurses and doctors decide whether they should give it.

So should you call 911 for a black widow bite?

Every bite is a little different, and every body is a little different. If you’re unsure what to do, call the Poison Center at 1.800.222.1222. Our nurses are really good at asking the right questions, and they can even contact the hospital or the emergency room that you’re going to and let them know you’re on the way and offer treatment advice.

Wash the area with soap and water or alcohol and talk to your doctor about a tetanus shot. Just like anything that breaks the skin, there’s an infection risk.

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Comments : 11 |
 

11 Comments for this post

 
October 12th, 2011 at 10:22 am

[...] market, local politics, technology & Charlottesville in general. Thanks for visiting! Thanks to the UVA Health System Blog for today’s story on spiders in Charlottesville. This is actually one of the more common questions my clients ask me – what kinds of spiders [...]

 
 
January 7th, 2012 at 8:10 am

You should take your friends advice seriously as brown recluses spiders are certainly more dangerous than black widows as they can produce far serious wounds and scars but I think that since you are in Virginia so you may not have to face them as I assume they cannot be found in Virginia.

 
 
September 21st, 2012 at 12:55 pm

I found a large spider in my kitchen, shortly after taking my dog to the vet when an ulcer on his leg burst. I think the spider bit my dog – and I also think it’s a hobo spider. We visited Seattle, WA earlier in the year and may have brought it home with us. We live in Arlington, VA and I see that hobo spiders are not supposed to be in VA. I have photos of the spider & of the bite on my dog’s leg. I’m especially interested in identifying the spider to make sure my dog gets the right treatment.
Thanks,
Cheryl

 
 
September 21st, 2012 at 1:28 pm

Hi Cheryl, so sorry to hear about your dog. I hope he/she feels better soon. I shared your post with Kristin, and she recommended you keep in touch with your vet about the bite. She said the Poison Center’s expertise is treating poisoning, not spider identification, but suggested you contact Michael Weaver, a professor of entomology at Virginia Tech (http://vtpp.ext.vt.edu/). Dr. Weaver’s email is mweaver@vt.edu.

 
 
May 2nd, 2013 at 12:57 am

Cheryl and Kristin:
My role at Virginia Tech involves primarily pesticide safety education. While I have over 100 live tarantulas and other arthropods that I keep in my office as part of our departmental (educational) “bug” zoo, I would suggest the following contact for all arthropod indentification: Mr.Eric Day, Manager, Virginia Tech Insect ID Lab, Department of Entomology (0319), Blacksburg, VA 24061 – idlab@vt.edu (http://www.insectid.ento.vt.edu/). Assistance with pest information and management is also available through your local Cooperative Extension office. In Virginia, the list of local offices can be found at: “http://www.ext.vt.edu/offices/index.html”

Kindest regards,

Mike Weaver, Ph.D., Professor of Entomology & Director, Virginia Tech Pesticide Programs, 302 Agnew Hall (0409), Blacksburg, VA 24061

 
 
June 3rd, 2013 at 5:09 pm

I am part of a co-op with a plantation/farm up in Fredericksburg and I get a box of goodies each week. My wife found a big spider in the box and she tossed the box over on the screened-in porch. About a week later, I found a large spider on the porch. It was pretty large and unusual looking. I am an avid mountain biker and love the outdoors. I was bitten by something as a kid and went into Anaphylactic shock so I pay very, very close attention to bugs, insects and spiders. So after catching him in a large tea pitcher and looking up pictures, I am positive it’s a brown recluse. From what I read online, they like cardboard and I bet he was living in the box that got shipped to the farm and then re-used for out goodies. I didn’t have the heart to kill him, so I let him go in a large field near my house. I figure he will live out his days and hopefully, be of no harm to anyone. But I say this to remind people that when they go to farms, outdoor markets, etc, that all kinds of bugs, spiders and insect can tag along with fresh produce or their containers! So keep your eyes open…

 
 
June 11th, 2013 at 3:40 pm

I live in Henrico County, Virginia and killed two brown recluse spiders today. I average killing 20 to 30 a year in the house and have been bitten once behind my right ear and on my left arm in the last three years while sleeping in a guest bedroom. I do have them in my house. I have also found them outside.

 
 
June 12th, 2013 at 2:37 pm

Brown Recluse spiders are small, not large. I’m not sure what pictures you matched it with. What size (in inches) was it?

 
 
June 18th, 2013 at 12:28 am

Where can I take a spider to have identified?

 
 
August 8th, 2013 at 9:57 pm

I live in Charlottesville and have found two Northern Black Widows – one in my garden and one in my garage. They very clearly look like Black Widows but instead of an hourglass they have red spots in a line on their abdomen. They really didn’t seem aggressive. I just relocated the one that was in the garage.

 
 
April 1st, 2014 at 2:27 am

Hate to tell you but there are brown recluse in virginia. I am in NOVA and we had a HUGE issue with them. We were catching tons of them in glue traps at our house. I had multiple pest companies varifiy that they were brown recluse. My husband was bit by one and the flesh around the bite started to die. The doctor had to give him treatment for it and he now has a permant scar from it.

 

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