Bark Scorpions in Central Texas

Identification: What a Striped Bark Scorpion Looks Like

Texas A&M AgriLife Extension describes the striped bark scorpion as yellowish tan with two broad, dark stripes running the length of the back and a dark triangular mark on the front of the head above the eyes. Adults grow to about two and a half inches long. Slender pedipalps, the pincer bearing arms in front, and a long slender tail set it apart from other Texas scorpions. The tail runs longer on males than on females, and immature scorpions are often lighter in color with a dark base to the pedipalps.

AgriLife records eighteen scorpion species statewide, but the striped bark scorpion is the only one that occurs across the entire state. Two species have been recorded near the Austin area specifically, according to the same publication, though the striped bark scorpion remains the one residents encounter almost exclusively.

Limestone Country: Why the Habitat Fits

The U.S. Geological Survey describes karst terrain as landscape created by the dissolution of soluble rock, principally limestone and dolomite, producing distinctive springs, caves, sinkholes, and fractures. The Edwards aquifer that underlies much of the Austin area, including Barton Springs, sits within this fractured limestone, and the same faulting that controls groundwater flow through the region also breaks the rock at the surface into countless cracks and crevices.

AgriLife Extension notes that a scorpion's body is flat, which lets it hide in small cracks and under stones, bark, wood, or other objects while it waits or searches for prey. Fractured limestone, retaining walls, and the rock landscaping common across the Hill Country give the striped bark scorpion exactly the kind of cover its body is built to exploit, right up to the foundation of a house.

Nightly Behavior and Life Cycle

Scorpions are nocturnal, hiding during the day and becoming active at night, a pattern AgriLife Extension ties to managing temperature and water balance in dry habitats. Striped bark scorpions are active foragers rather than burrowers, hunting insects, spiders, centipedes, earthworms, and even other scorpions, then using their pincers to crush prey and draw it toward the mouth.

The striped bark scorpion mates in fall, spring, or early summer, and AgriLife reports a gestation period of about eight months. Females give birth to thirteen to forty seven young, thirty one on average, delivered live. The young climb onto the mother's back within days of birth, molt three to seven days after birth, and remain with her for another three to seven days before leaving to fend for themselves after about two weeks. Five to six molts bring a striped bark scorpion to maturity, and AgriLife lists its typical lifespan at about four years.

Why They Come Indoors

Striped bark scorpions climb readily, and AgriLife Extension notes they are often found in the attics of homes after climbing trees and walls to get there. During periods of hot weather, the same source states, scorpions may move from those attics into living areas below to escape the high temperatures overhead.

Wizzie Brown, the AgriLife Extension entomologist for Travis County, described this to AgriLife Today by pointing to the scorpion's flat body, which lets it hide in small cracks and under stones, bark, wood, or other objects as it searches for prey, whether that search happens to end outside or inside a wall cavity. The same article notes that calls about scorpions rise in South and Central Texas during hot, dry summer stretches, as the animals move toward cover and away from extreme heat.

If a Sting Happens

AgriLife Extension reports that stings from Texas scorpions produce only moderate reactions in most people, since the venom of local species has comparatively little effect on the nervous system. Even so, a sting can cause pain, and AgriLife recommends watching the person closely afterward, since allergic reactions are possible with any arthropod venom. An ice pack applied to the site relieves some pain; if swelling or pain persists, or if breathing difficulty occurs, immediate medical attention is necessary.

The CDC's occupational safety guidance for people who work outdoors recommends shaking out clothing and shoes before putting them on and wearing long sleeved shirts and long pants when working in areas known to hold scorpions, precautions that apply just as well in a backyard or garage as on a job site.

Exclusion: Closing the Routes Scorpions Use

AgriLife Extension states plainly that scorpions are difficult to control with insecticides alone, and that the first control strategy is modifying the area surrounding a structure. The steps below come directly from that guidance.

Anyone who wants pesticides applied by a professional should confirm the applicator holds a current license. The Texas Department of Agriculture's Structural Pest Control Service licenses and regulates anyone in the business of pest control for hire, including small operators, and consumers can direct questions or complaints about unlicensed activity to the department.

1. Remove all trash, logs, boards, stones, bricks, and other debris from around the structure, since these are exactly the objects a flat bodied scorpion hides beneath.
2. Keep grass mowed close to the structure and prune bushes and overhanging tree branches back from the walls, since branches can give scorpions a path up to the roof.
3. Store garbage containers in a frame that keeps them above ground level.
4. Never bring firewood inside the structure unless it goes directly onto the fire.
5. Install weather stripping around loose fitting doors and windows.
6. Plug weep holes in stone or brick veneer with steel wool, copper mesh, pieces of nylon scouring pad, or small squares of screen wire.
7. Use sealant around roof eaves, pipes, and any other cracks leading into the structure.
8. Keep window screens in good repair and make sure they fit tightly in the frame.