January 10, 2020
In our Houston service area, we have a few venomous spiders to contend with. Today, we're looking at the southern black widow, which is known scientifically as Latrodectus mactans (Fabricius) because the more you know, the better off you'll be.
The southern black widow is jet black and may have a red hourglass shape on the bottom of its abdomen. But it doesn't always have this shape. Sometimes there may only be remnants of red or red dots, rather than the two triangles that come together to form the hourglass shape. These black widows may also have red dots on the top of the abdomen. If you see a black, shiny, hairless spider, it is best to stay away, even if you don't see red markings.
A female southern black widow spider will create a beige egg sac that is about half the size of a dime. Inside this sac, there may be around 220 eggs. The spiderlings of a southern black widow are white when they hatch and they do not have the hourglass or red spot patterns that the adults have. As they molt, they start looking more and more like the adults, taking on the red dots, red triangles or hourglass marking, as well as the jet-black coloration.
The southern black widow prefers to be outside and only gets into homes by accident. Inside a home, these spiders prefer secluded areas. They are more likely to get into exterior structures, such as barns, garages, sheds, and outhouses. Be cautious in exterior structures that are used to store items. These are particularly interesting to black widows because they are interesting to the bugs black widows eat.
The webs created by southern black widows are usually low to the ground, though they can be several meters up. You're most likely to find webs in wood piles and piles of organic debris. They'll also commonly create webs in between stones, rocks, bricks and concrete blocks. If rodents have dug holes in your yard, a black widow may take up residence in one of the holes. The web of a southern black widow looks tangled but they are actually crafted to precision. If you look closely, there is a method to the madness. You may also notice that the webbing is strong and threads may make a snapping noise when you break one.
You can keep these spiders out of your home by doing the following:
- Reduce moisture around your home. Moisture attracts bugs and bugs lure black widow spiders in close to your home. Everything you do to reduce bugs will have an impact on southern black widow spider activity.
- Reduce piles in your yard, especially wood, brush and leaf piles.
- Seal entry points. There are many potential entry points around your home that widows will take advantage of. The most common are gaps around plumbing and wire conduit, cracks in foundation walls, and holes created by wood-damaging pests, such as mice and rats. These holes should be sealed up quickly to keep a wide range of pests out of your Houston area home.
- When you're working in your yard, be sure to wear garden gloves or work gloves. Most bites occur when reaching under a piece of wood or stones. These are common hiding places. Be cautious when you are moving boxes and other items within storage areas.
- Black widow spiders hide in holes and they often mistake boots and other footwear as holes. Shake your footwear out before sliding your feet in.
A black widow can mistake crumbled bedding for potential holes and hiding places. Check before you get into an unmade bed. Keep in mind that it is rare to find a black widow in a bed because bedrooms are not secluded and quiet enough for these spiders.
- Clothing and towels left on the floor can give harborage to a spider. Be cautious when picking these items up or placing them against your skin.
How Bad is a Southern Black Widow Spider Bite?
A bite from one of these spiders is considered medically important and it can have you making a trip to the hospital. While you can get very sick from a southern black widow bite, it shouldn't be life-threatening if you seek medical attention. But it is still very unpleasant.
Ongoing residential pest control is the best way to reduce black widow spiders around your home and prevent them from getting into your home. If you need assistance with setting up an effective pest control plan for your Houston home, we'd love the opportunity to help.