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This Week’s Creature Feature: Black Widow

She comes out at night

      Late one evening, near the end of summer, I grabbed a flashlight to take an evening walk. As I swung the light around the dark garage, I saw a very dark object suspended halfway up the back corner. It became obvious, as I neared, that I had found a black widow spider.
      The next morning, I completely cleared out the garage. But the night-stalking spider had retreated into a crack in the cement wall. I did not find any egg cases.  
      There is a stormwater drain at the edge of my backyard and another at the edge of the street in front of my house. Over the years, I have found black widows near the opening of those drains. But this was the first time one had crossed the 100 feet to my house.  
      The spiders are named for the tendency of the female to eat the mated partner. Black widow spiders are in the genus Latrodectus, which includes the deadly red-backed spider in Australia.
      The United States has three species of black widows, with the northern black widow and the southern black widow overlapping their ranges in Maryland. The desert or western black widow spider lives out in the desert southwest.
       All three species possess a neurotoxic venom, and a bite can cause 24 hours of severe muscle pain and nausea. The venom is 15 times more potent than a rattlesnake’s, but the spiders do not have the volume to be deadly.
      In the spring, a hundred or more small spiders hatch out of one of several egg sacks laid the preceding fall. The young spread out and find suitable low dark spots to hide They eat various insects but seem to favor ground crawlers like beetles.
      As they age, the female southern spiders turn black with a distinctive red blotch, an hourglass, under their abdomen. The northern female is black with the distinctive red dot and yellow stripes. The males of both species are small with paler bodies with horizontal yellow lines and a red vertical stripe. The goal of the male is to find a female that has just eaten, which gives him less chance of being consumed.
        A female’s lifespan in a cold climate is generally one year.
        Black widows are easily discovered by their distinctive chaotic webs. Low to the ground, the webs are a series of haphazard vertically oriented single strands. Each strand is sticky and very strong. A broomstraw will break through most spider webs, like a cobweb, but it will bend as it hits a black widow web. Strong as steel of the same diameter, the strands are the basis of ultra-thin fishing line called SpiderWire.
      The spiders can move surprisingly fast for about six inches. When cornered, they lift up on their hind legs to show their fangs. Most bites occur when they are grabbed — I assume by accident. Over the past decade, no fatalities have been reported.
      The spider I found in my garage did not survive our encounter. I have since found more under a portable basketball hoop.