North American Spiders in Texas

Texas might not be the best place for someone with arachnophobia.

Scientists have been aware of the importance of the spider in ecosystems since the early 1990s. In a state of cotton, citrus and other agricultural ecosystems, farmers have come also to recognize the importance of the proliferation of spiders in their crop fields. People in Texas can be glad that spiders are such useful creatures. There are close to 900 species of spiders in the state.

Poisonous Spiders

There are five species of brown recluse spiders in Texas. Two of these species are poisonous. It is considered safe to stay out of range of any recluse spiders. Doing so is easier said than done. They often live in proximity to humans, hiding just about anywhere, including clothes, bathrooms and anywhere there's space out of site. They come out at night to hunt and sometimes bite people who roll over on them in their sleep. There are also three species of black widows in the state. These spiders can be a variety of colors and have colored markings, but the hour glass shape mark on the abdomen give them away as widows. They are not aggressive but will bite if accidentally disturbed. The bite of these spiders is miserable, but rarely fatal.

Scary But Non-Poisonous

There are a few spider types that are generally thought to be poisonous but are more feared than dangerous. The tarantula fits nicely into this group. They get large, often more than 3 inches long. Jumping spiders are stocky, hairy and sometimes brightly colored, most being black and white. They stalk prey and leap to catch it. They leave a string of webbing behind them when they jump to avoid falling. Wolf spiders build webs for shelter and not for hunting prey. They are spooky little creatures with eyes that glow in lights at night. If you you shine a flashlight in your yard at night and see those eyes, though, you know you are being well protected from other insects.

Orb Weavers

Spiders that build roundish webs are known as orb weavers. There are many species of these spiders in Texas. The largest is the yellow garden spider, with a body alone measuring more than 1 inch in length. The strangest looking of this class of spider is the spiny-backed orb weaver, which has a crab-shaped body with protruding spines. Orb weavers are happy in gardens and other outdoor spaces and are extremely beneficial, eating many insects we consider pests, such as mosquitoes and flies. Garden spiders can be prevalent enough in fields to be regarded as natural pest control for crop plants and should be respected as beneficial.

Strange Communal Behavior

In 2007, park officials at Lake Tawakoni discovered a massive spider web at least 600 feet long on the lake trail, covering the trees and blocking sunshine in spots. The web was actually a conglomeration of individual webs built using common threads and resulting in a lace of webs containing millions of spiders. A sample of 250 spider specimens revealed the webs were concentrated efforts between 16 identified genera of spiders from 12 families. While this phenomenon has been seen in other locations, usually the tropics, it is an extremely rare occurrence.

References

• University of Michigan: Spider Conservation in the United States; Kevin L. Skerl
• Texas Agricultural Extension Service: Spiders; John A. Jackman
• Texas A&M University: Beneficials In The Garden: Spiny Orb Weaver Spider; Candice Hawkinson
• Texas Entomology: Giant Spider Web in an East Texas State Park - 2007