The stealth hunters of the garden world, most spiders lie in wait for unsuspecting insect prey. Additional hunting tools may include a sticky net to trap prey and venom to subdue it. San Antonio is in south-central Texas and has a moderate subtropical climate with warm winters and long, hot summers. Rainfall averages about 29 inches a year. Such conditions favor insect diversity and, as a result, a diverse spider population. Spiders can bite humans and cause pain, but only a few are dangerous.
Thanks to the popular children's book "Charlotte's Web," many people think of an orb-weaving garden spider such as Charlotte when "spider" is mentioned. Common throughout North America, there are several kinds of garden spiders that spin large, circular webs across garden paths and other open areas. The yellow garden spider is one of the most common orb-weavers, destroying many garden pests. They don't bite unless handled or perhaps if you walk into their nets, and the bite isn't dangerous.
Two kinds of spiders that live in the San Antonio area are dangerous. First is the black widow spider, a dweller of dark, undisturbed places. The spider's venom is neurotoxic and causes symptoms such as stomach cramping, nausea and pain. Females have a rounded, glistening black abdomen with a red marking on the bottom and long, pointed legs. They build a tangled irregular web in attics, basements and woodpiles. Another secretive spider, the brown recluse, has a fiddle-shaped black marking on the top side behind the head. Besides causing overall symptoms, its venom can destroy body tissues at the bite site. Both spiders aren't aggressive but will bite if disturbed. Seek medical help if you think you've been bitten, and preserve the spider that bit you if possible.
Some spiders are active hunters, with good eyesight and fast speeds. They run down and jump on their prey. Examples are wolf spiders and jumping spiders. Wolf spiders are fairly large, brown to gray spiders often marked with black stripes. Female wolf spiders carry their babies on their backs. Jumping spiders are small and can jump large distances considering their size. They can have bright abdominal markings of red, orange, white or yellow. Green lynx spiders are pouncers and live in vegetation. These slender, green spiders are about 1/2 inch long.
Spiders that are over an inch long attract a lot of attention. The largest spiders in the San Antonio area are tarantulas. Active in warm months and mostly at night, they are brown to black, hairy spiders that can be 3 inches long. They can give a painful bite if handled. The trapdoor spider is another large, dark-colored spider. People hardly ever see it because it lives in an underground burrow outfitted with a hinged lid. In 2011, due to flooding, one San Antonio area became aware of trapdoor spiders when water forced dozens of them out of their burrows.
A rare spider made San Antonio news in 2012 when it was rediscovered in a highway construction area. Called the Braken Bat Cave meshweaver, this small, brown, nonvenomous, cave-dwelling spider doesn't have eyes. An endangered species protected by the U.S. Fish and Wildlife agency, the spider hadn't been seen since it was first identified in 1980, but it brought the construction project on Highway 151 to a halt.