Striped Bark Scorpion — Fact Sheet

Scientific name: Centruroides vittatus (Say, 1821) Common names: Striped bark scorpion, Texas bark scorpion, common striped scorpion Order: Scorpiones (family Buthidae) Status in the San Antonio / Boerne corridor: Native, abundant, the single most common scorpion in Texas — the only species found throughout the entire state

At a glance

Size	25–70 mm (1" to 2-3/4")
Color	Yellowish-tan body with two distinctive dark longitudinal stripes down the back; dark triangular mark above eyes
Body type	Arachnid (8 legs); long slender body, slender pedipalps (pincers), thin tail
Active period	Nocturnal year-round; mating Fall, Spring, early summer
Sting	Single, defensive; sharp burning pain 15–20 minutes; rarely medically serious
Habitat in homes	Attics, wall voids, under siding, in stored items
Famous trait	Glows blue-green under UV black light

Why this fact sheet exists in a stinging insect content set

Striped bark scorpions are arachnids, not insects. They belong to the same broader group as spiders, ticks, and mites. Including them in our content set is a deliberate choice based on customer search behavior:

• Every "stinging pests in Texas" customer query inevitably includes scorpions. People do not draw the entomologist's distinction between insects and arachnids when they are looking up "things that sting."
• In the San Antonio to Boerne corridor specifically, scorpions are one of the top three pest concerns for new homeowners, alongside fire ants and wasps.
• Scorpion-specific service calls are seasonally significant for our market. Hill Country homeowners deal with attic scorpion populations as a recurring residential issue.
• The biology is relevant to stinging-pest content — the venom apparatus, sting effects, and treatment considerations all parallel those for stinging Hymenoptera.

So this is a stinging-pest fact sheet that happens to be about an arachnid. The treatment approach overlaps significantly with Hymenoptera work; the biology is genuinely fascinating; and customers expect coverage.

Identification

The striped bark scorpion is the only scorpion most Hill Country homeowners will ever encounter, and the identification is fairly reliable once you know what to look for.

Diagnostic features:

• Yellowish-tan to pale-yellow body — light enough to look almost amber under flashlight
• Two broad dark longitudinal stripes running down the dorsal surface of the abdomen — this is the namesake feature
• Dark triangular mark on the carapace (the head shield) in the area above the median and lateral eyes
• Slender pedipalps (the front "claws") — narrow, not robust
• Long thin tail — proportionally longer than the body in adults
• Dark brown to black tip on the tail (the postabdomen) and the bases of the pedipalps in younger specimens

Size and dimorphism: Adults average about 60 mm (2-3/8") in length. The tail is longer in males than in females. Younger specimens are overall lighter in color than adults. Populations in the Big Bend region of West Texas can be only faintly marked or completely pale, but the central Texas population shows the full pattern reliably.

Distinguishing from other Texas scorpions

Texas hosts about 20 scorpion species. In the San Antonio / Hill Country area, one species dominates so completely that you can identify by location alone — C. vittatus is essentially the only species you will encounter outside of West Texas.

For comparison purposes:

• **Arizona bark scorpion (Centruroides sculpturatus): West Texas only (El Paso area, Big Bend). Smoother, more uniformly pale yellow without distinct stripes. Significantly more medically dangerous** — its venom is the most potent of any North American scorpion. Not present in the San Antonio corridor.
• Other Texas scorpions: Mostly Vaejovis species, which are typically larger, more robust, with thicker pedipalps. Found in West and South Texas in arid habitats. Not common in residential settings.

If you find a scorpion in a Boerne, Bulverde, or Stone Oak attic, it is Centruroides vittatus. Period.

Biology and behavior

Anatomy refresher

Scorpions are arachnids, distinguished from other arachnids by their elongated body plan, segmented postabdomen ("tail"), and venomous stinger (telson) at the tail tip. Eight legs (the four pairs walking legs), plus pedipalps (the lobster-like pincers) used for grasping prey, plus chelicerae (small mouthparts).

The "tail" is technically the metasoma — five segments leading to the telson. The telson contains paired venom glands and the sharp aculeus (the sting). When a scorpion stings, the tail arches forward over the body to drive the aculeus into the target.

Hunting and feeding

Striped bark scorpions are nocturnal predators. They emerge from daytime shelters at sunset and forage on or near the ground for spiders, centipedes, crickets, flies, beetles, and other small arthropods.

The hunting strategy depends on a remarkable sensory system. Comblike chemical receptor organs called pectines on their undersides contact the ground as they walk, providing chemical and tactile information about substrates and prey. They use vibration sensing through specialized leg organs to detect movement of nearby prey. Combined with their venom, this allows efficient hunting in complete darkness.

The actual hunt: scorpion grabs prey with the pedipalps and crushes it. Tail arches forward, sting delivered to the prey's body. Venom paralyzes (insects often jerk compulsively, then go limp). Prey is held in the rigid grasp until it dies.

Eating is unusual. Scorpions have very small mouths (chelicerae), so they cannot consume solid food. They digest externally — coughing digestive fluids onto the prey, then sucking up the liquefied remains. The behavior has been compared to drinking a smoothie. A meal can last several hours; a single large prey item can sustain a scorpion for weeks.

Reproduction

Mating occurs in fall, spring, and early summer. Courtship involves an elaborate "promenade à deux" in which the male grasps the female's pedipalps and walks her over a flat surface while depositing a spermatophore that the female then takes up.

Striped bark scorpions give birth to live young. Embryos are nourished inside the female's body via a placental connection — unusual among arthropods. Gestation takes about eight months. Broods average around 30 young, occasionally up to 50.

Newborn scorpions climb onto the mother's back immediately after birth and ride there during their first instar. After the first molt, they disperse and lead independent lives. Scorpions molt an average of six times before maturity, which can take several years to reach.

This brood-carrying behavior — a female scorpion with 20 to 30 tiny pale young clustered on her back — is one of the more memorable encounters in Hill Country pest work. We see it most often in May and June.

Habitat and shelter

The genus name Centruroides implies semi-arboreal habits, and striped bark scorpions are notably climbers. They are described as "bark scorpions" because of their distinct association with dead vegetation, fallen logs, and human dwellings. Unlike burrowing scorpions that excavate underground tunnels, C. vittatus shelters in pre-existing crevices and surfaces.

Daytime shelter locations include:

• Under rocks and surface debris
• Inside fallen logs and dead vegetation
• Beneath tree bark (especially in cedars and live oaks)
• In old rural structures — barns, sheds, outbuildings
• In houses — particularly attics, wall voids, garages, storage areas, beneath siding
• In stored items — boxes, shoes left outside, folded tarps, firewood

The waxy cuticle that covers their bodies helps prevent water loss, which is critical for survival in dry Hill Country summer conditions. Their semi-arboreal climbing ability means they regularly access elevated locations — they will climb wall studs, stack stones, and even smooth surfaces with sufficient texture.

The "scorpions in the attic" problem in the Hill Country is essentially universal. Stone-veneer homes with traditional shingle or tile roofing accumulate scorpion populations in the attic space year over year, with seasonal movement through wall voids into the living space.

Venom — the science

The venom of C. vittatus contains multiple bioactive components:

• CvlV4 toxin: targets sodium channels in dorsal root ganglia of nociceptors (sensory neurons that detect pain), preventing channel inactivation and resulting in prolonged action potentials. This is the molecular mechanism for the sharp burning pain of the sting.
• Multiple allergen proteins: at least nine identified through SDS-PAGE and IgE immunoblot analysis, capable of triggering hypersensitive immune responses
• Enzymes: alkaline phosphatase, esterase, esterase lipase, acid phosphatase, and phospholipase A — collectively contributing to local tissue effects

A 2017 study published in PLOS One established that adult striped bark scorpion venom is approximately 2.7 times more potent than juvenile venom, based on probit analysis of ED50 values (50.1 μg/g for adults vs. 134.2 μg/g for juveniles). The difference is driven by ontogenetic shifts in expression of venom genes — adults express more sodium channel modulators, while juveniles preferentially express potassium channel modulators. This is one of the better-documented examples of age-dependent venom variation in scorpions.

The complete C. vittatus genome has been sequenced and annotated, with venom toxin genes mapped to specific contigs and scaffolds. This is one of only three scorpion species worldwide with a published genome assembly.

Why scorpions glow under UV light

The exoskeleton (cuticle) of scorpions contains compounds that fluoresce blue-green when illuminated by ultraviolet light (a "black light"). This is universal across scorpion species and is one of the most reliable identification techniques.

Why this happens is genuinely unknown. The fluorescence is produced by chemicals in the hyaline layer of the cuticle, including beta-carboline and 7-hydroxy-4-methylcoumarin. The biological function — why scorpion cuticle evolved to fluoresce — has not been definitively established. Hypotheses include:

• UV light detection. Scorpions lack typical compound eyes and may use their entire body as a UV light sensor, with fluorescence acting as part of the detection mechanism.
• Predator deterrence. UV-fluorescing surfaces are detectable to some animals, possibly serving as a warning signal.
• Prey attraction or avoidance. The fluorescence might affect prey behavior in some way.
• Photoprotection. The compounds might serve a protective function against UV damage.
• Byproduct. It might be an evolutionarily neutral consequence of cuticle chemistry.

What is established: a black-light flashlight (sold commercially as "scorpion flashlights" or used in geology and forensics) makes scorpion detection at night dramatically easier. A scorpion that would be impossible to see by white light against complex substrate becomes a brilliant blue-green spot under UV. This is the standard method for night surveys on properties with persistent scorpion problems.

Local context — San Antonio and the Hill Country

The striped bark scorpion is essentially universal across our service area. The intensity of populations varies by habitat:

• Boerne, Fair Oaks Ranch, Bulverde, Spring Branch, Comfort, Bergheim, Helotes: high scorpion pressure. Limestone-and-cedar Hill Country habitat is essentially ideal — abundant rock crevices, mature live oaks providing bark shelter, transitions between turfgrass and natural areas, dry well-drained soils. Custom homes in these communities routinely have established attic populations.
• Stone Oak / Sonterra / Encino Park: moderate to high. The wooded subdivisions north of Loop 1604 transition between native habitat and developed lots; scorpion pressure is significant.
• Alamo Heights, Olmos Park, Terrell Hills, Monte Vista: moderate. Older established neighborhoods with mature trees and rock landscape elements support populations.
• Central San Antonio (downtown, near downtown): low to moderate. Dense urban infrastructure and turf-dominated yards provide less ideal habitat.
• Southside and East San Antonio brush corridors: moderate. Brush-country habitat is suitable but less ideal than the Hill Country.
• New Braunfels, Canyon Lake, Kerrville: high. Same Hill Country pattern as Boerne.

The signature local presentation: a homeowner in Boerne or Fair Oaks Ranch finds a scorpion in the bathtub, in a closet, in a child's bedroom, or in a folded towel. They call concerned. Inspection reveals an attic population that has been established for years, with seasonal movement through wall voids into the living space — particularly during late summer heat and winter cold transitions when scorpions seek temperature-stable interior environments.

Specific Hill Country considerations

Stone-veneer homes are particularly susceptible. The gaps between veneer stones and the structural sheathing behind them provide nearly perfect scorpion habitat — sheltered, stable temperature, abundant insect prey. Most Hill Country custom homes built since 2000 have stone veneer on at least one exterior surface.

Outdoor stacked-stone retaining walls and landscape features are scorpion habitat. Beautiful in design, problematic in pest pressure.

Cedar elimination work (clearing of Ashe juniper, locally called "cedar" though it is technically not a cedar) on Hill Country acreage temporarily increases scorpion encounters as displaced populations seek new shelter — including in nearby buildings.

Outdoor pavilions, pool houses, and casitas are all scorpion-attractive structures. Use surveys reveal scorpion presence in 60–80% of unmaintained outbuildings on Hill Country acreage.

Risk to humans and pets

Low to moderate. The striped bark scorpion sting is genuinely painful but rarely medically serious for healthy adults.

Typical sting effects:

• Sharp pain at the sting site, sometimes described as a hot needle or wasp-sting equivalent
• Burning sensation lasting 15–20 minutes at peak, fading over 2 hours
• Local swelling, redness, and minor edema
• About 10% of stings produce a tingling or numbness sensation, sometimes described as feeling like an electric shock traveling up the affected arm or leg
• Symptoms typically fully resolve within 24 hours

More serious cases (rare):

• Allergic reactions, including anaphylaxis (the only mechanism by which a C. vittatus sting can be life-threatening)
• Symptoms include hives, nausea, vomiting, respiratory distress
• Muscle spasms and jerky eye movements are typically the first serious symptoms
• Children under 6, the elderly, and immunocompromised individuals are at higher relative risk

Deaths from striped bark scorpion stings are essentially unheard of in healthy adults. The literature documents no confirmed deaths attributable to C. vittatus venom directly — only via anaphylactic shock. This contrasts with the Arizona bark scorpion (C. sculpturatus) and the truly dangerous Centruroides species in Mexico, where pediatric deaths from envenomation do occur.

Pets: Dogs and cats can be stung when investigating scorpions. Reactions vary from mild (paw favoring, brief whining) to more significant local swelling. Veterinary attention is warranted if symptoms persist beyond a few hours or if systemic signs appear.

First aid

Standard care for a striped bark scorpion sting:

• Wash the area with soap and water
• Ice pack on the sting site (10 minutes on, 10 minutes off — shorter if circulation issues)
• Keep the affected area still to slow venom spread
• Loosen tight clothing and remove jewelry in case of swelling
• Oral antihistamine (Benadryl) for allergic-type symptoms
• Seek emergency care if serious symptoms develop (call Poison Control at 1-800-222-1222)

Treatment approach

Scorpion control is the most genuinely difficult ongoing pest management challenge in our service area. Reasons:

• Scorpions are mobile, climb, fit through small gaps
• They reproduce slowly but persist for years
• They shelter in difficult-to-treat areas (attic insulation, wall voids, stone veneer cavities)
• Insecticide tolerance is high — scorpion exoskeletons are remarkably resistant to most contact insecticides
• They have no nest to target, unlike social insects
• They are nocturnal, making observation and treatment timing tricky

Our standard approach for established Hill Country scorpion populations:

Identification and survey:

• UV black light night survey to identify population locations and intensity
• Interior survey (attic, garages, crawl spaces) for harborage and entry points
• Exterior perimeter assessment — landscape features, stone veneer gaps, wood piles, debris

Exclusion:

• Sealing of wall void entry points, soffit gaps, weep holes (consult on screen-vs-seal, since weep holes serve a moisture-management function)
• Door sweep installation and replacement
• Window screen repair
• Foundation crack sealing

Habitat modification:

• Removal of ground-level debris, woodpiles within 20 feet of structure
• Trim vegetation from contact with structure
• Remove or relocate stacked stone landscape features near house perimeter
• Address moisture issues that attract prey insects

Chemical treatment:

• Residual perimeter treatment with appropriate labeled products (microencapsulated or wettable powder formulations adhere to scorpion cuticle better than aqueous solutions)
• Granular treatment of landscape beds and turf areas
• Crack-and-crevice treatment of identified harborage
• Attic dust treatment for established interior populations
• Routine repeat treatment on a quarterly schedule for properties with persistent issues

Realistic expectations:

• True elimination of scorpions from Hill Country property is essentially impossible
• Goal is significant reduction and exclusion from living spaces
• Properties that achieve "no scorpion sightings inside" status typically do so through combined exclusion + ongoing perimeter treatment
• Year 1 treatment shows dramatic reduction; years 2+ stabilize at much lower population levels

Odd, funny, and genuinely true

• Striped bark scorpions glow blue-green under UV light, like every other scorpion species. Why this happens is still genuinely unknown despite decades of research. The compounds responsible (beta-carboline and 7-hydroxy-4-methylcoumarin) are well-characterized, but the evolutionary function remains debated.
• Scorpions can survive months without food. A well-fed striped bark scorpion can persist 6+ months without eating, drawing on stored fat reserves. This is part of why eliminating populations is so difficult — depriving them of prey for short periods does not significantly reduce numbers.
• **The genus Centruroides contains some of the most medically dangerous scorpions in North America.** C. sculpturatus (Arizona bark scorpion) is the most dangerous; multiple Mexican Centruroides species cause pediatric deaths annually. C. vittatus is in the same genus but is comparatively mild — sometimes called "the gentle relative" in the keeping community.
• Striped bark scorpions are kept as pets. They are popular among scorpion enthusiasts because of their relatively mild venom, attractive striped patterning, and active behavior. Online care guides treat C. vittatus as a beginner-friendly scorpion species. Texas pest control operators occasionally find escaped pet scorpions in the wild — almost always C. vittatus.
• They can survive being frozen. Documented research shows that C. vittatus can survive brief subfreezing temperatures and even short periods of ice formation in their bodies, then revive when temperatures rise. This freeze tolerance is part of how they persist in the northernmost parts of their range (as far north as southern Nebraska).
• A single mother carries 20–30 babies on her back for the first instar. If you ever see a scorpion that appears to have a "fuzzy" or textured back in May or June, look closely — it's a mother carrying her brood. The young rest on her back and feed on egg yolk reserves until their first molt, after which they disperse.
• The published genome has 760 megabases of DNA — about a quarter the size of the human genome. The assembly identified 36,189 protein-coding genes. Of these, 19 sodium-channel toxin genes and 14 potassium-channel toxin genes have been mapped to specific scaffolds — the molecular basis for the venom complexity.
• Scorpions are ancient. The oldest scorpion fossils date to approximately 430 million years ago, in the Silurian period. Scorpion body plan has changed remarkably little since then. The striped bark scorpion you find in your attic is using essentially the same anatomical design that existed before the first land plants formed forests.
• The species was first formally described by Thomas Say in 1821 — the same American entomologist who later described Brachygastra mellifica (the Mexican honey wasp). Say's work in the 1820s and 1830s established many of the foundational species descriptions for North American arthropods.
• They eat each other. Cannibalism is documented in C. vittatus — larger individuals will prey on smaller ones, particularly if food is scarce. Mothers also occasionally consume their own offspring. This is part of why population density does not increase indefinitely in confined habitats.
• The stripes are aposematic — warning coloration. The dark dorsal stripes against a yellowish background signal "I am venomous" to potential predators, and predatory birds and small mammals that attempt to eat a scorpion learn the association quickly.
• They are detected by hunting tarantulas as prey. Texas brown tarantulas and other large tarantula species in the Hill Country eat scorpions — including striped bark scorpions. The interaction is one of the few cases where a Texas spider regularly preys on a venomous arthropod.
• A scorpion in the bathtub is almost always trapped, not arriving via the drain. They climb walls in search of prey or shelter, slip into the smooth porcelain bathtub, and cannot climb back out due to the slick surface. This is the single most common "found a scorpion in the house" scenario in the Hill Country.

FAQ hooks (for LuperIQ / SEO)

• How do I get rid of scorpions in my house?
• Are scorpions in the Hill Country dangerous?
• Why do scorpions glow under black light?
• Scorpion in my bed — what do I do?
• How can I tell if a scorpion sting is dangerous?
• Why do I have so many scorpions in my attic?
• What kind of scorpions are in San Antonio?
• Can scorpions kill dogs or cats?

Sources consulted for this fact sheet include the Wikipedia striped bark scorpion account citing Say's 1821 original description, the Texas A&M AgriLife Extension Field Guide to Common Texas Insects entry on Centruroides vittatus, the Animal Diversity Web species account by Schaefer/Fabritius (2001), peer-reviewed research on age-dependent venom variation (PLOS One 2017), the published genome assembly (G3 Genes|Genomes|Genetics, 2024), Earth Sky's natural history coverage by Alex Reshanov, the Reliant Pest Control medical information summary, and the Tarantula Collective species profile for keeping community context. Distribution information reflects the comprehensive Centruroides distribution work of Sissom and others. Venom biology details reflect the CvlV4 toxin characterization in scientific literature on Centruroides venom proteomics.