Centruroides vittatus

Geographic Range

Centruroides vittatus is probably the most frequently encountered scorpion in the United States. The striped scorpions' range radiates outward from Texas, where it is most heavily concentrated, into Arkansas, Colorado, Illinois, Kansas, Louisiana, Mississippi, Missouri, Nebraska, New Mexico, Oklahoma, and Tennessee. It is also found in the Mexican states of Tamaulipas, Coahuila, Nuevo Leon, Chihahua, and Durango. (Stockwell 1996, Drees & Jackman 1998) (Drees and Jackman, 1998; Stockwell, 2/8/96)

Habitat

Centruroides vittatus can be found indoors or outdoors in an array of habitats. These scorpions are considered "bark scorpions" and are typically nocturnal in their habitats. They hide in damp, cool areas under rocks, boards, fallen logs, dead vegetation, and inside human dwellings. (Drees & Jackman 1998, Ellis 1975)

Physical Description

The striped scorpion seldom attains lengths greater than 3 inches, averaging 2 3/8 inches. The tail of the scorpion is longer in males than in females. Body color varies from yellowish to tan for adults. Younger scorpions may be overall lighter in color, and the last segment of the body and the bases of the pedipalps are dark brown to black. Two distinguishing characteristics are two broad blackish stripes on the upper surface of the abdomen, and a dark triangular mark on the front portion of the head region in the area over the median and lateral eyes. This species has slender pedipalps and a long slender tail. (Ellis 1975, Drees & Jackman 1998)

Reproduction

Mating occurs in the fall, spring, and early summer. Embryos are nourished in the female's body via a placental connection. Gestation is estimated to take about eight months. Broods may contain upwards of 50 young, but average around 30. The young climb on the mothers back after birth and soon molt. After the first molt they disperse and lead independent lives. Scorpions molt an average of six times before maturity. Adult scorpions can produce several broods. (Milne & Milne 1980, Stockwell 1996, Drees & Jackman 1998)

Behavior

Scorpions remain sheltered in the daytime and become active at night, which helps with thermoregulation and water balance. Perhaps these scorpions most interesting behavior though, is their elaborate courtship ritual that may last for hours. The two scorpions grasp each other's pincers and jaws and dance back and forth. Finally, the male deposits a sac of sperm on the ground and pulls the female over it. Then, she picks the sac up with a special organ on her abdomen and fertilization occurs. (Miller 1988, Drees & Jackman 1998)

Food Habits

The striped scorpion is primarily insectivorous, consuming mostly spiders, centipedes, crickets, flies, beetles, and other small insects. The scorpion stalks its prey mostly at night and depends on its senses of touch and smell. Comblike chemical receptor organs on their undersides contact the ground as they walk, which helps them track prey. Theses scorpions catch their food by grabbing and crushing them with their powerful pinchers. They then bring their tail over their body and sting the victims. The prey jerk compulsively and are paralyzed by the venom. They die in the scorpions' rigid grasp. The scorpions then chew the prey into a semi-liquid state, that they can suck up with their tiny mouths. (Miller 1988, Townsend 1996)

Economic Importance for Humans: Positive

Scorpions help control the local insect population.

Economic Importance for Humans: Negative

Scorpions will strike if touched or grabbed by humans. The poison glands in the swollen tip of the tail secrete a venom that is a neurotoxic and is deadly to insects and causes extreme discomfort in humans. The sting sensation is a sharp pain that lasts, on average, about 15 to 20 minutes. Reactions vary depending on how much venom the scorpion has at the time. The sting is very rarely fatal, and even then, death is due to anaphylactic shock, not the direct toxic effects of the venom. (Townsend 1996, Parker 1982, Miller 1988)

Conservation Status

These scorpions have become associated with homes in Texas and the surrounding areas. Human presence has given them new places to find shelter. (Drees & Jackman 1998)

Other Comments

The striped scorpions body is covered with a waxy cuticle that helps prevent dessication. The scorpion cuticle flouresces under ultraviolet light, which helps when collecting or observing them at night. (Drees & Jackman 1998)

Contributors

Jason Schaefer (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

native range

the area in which the animal is naturally found, the region in which it is endemic.

References

Drees, B., J. Jackman. 1998. A Field Guide to Common Texas Insects. Houston: Gulf Publishing Company.

Ellis, M. 1975. Dangerous Plants, Snakes, Arthropods and Marine Life of Texas. U.S. Department of Health, Education, and Welfare.

McWest, K. 2004. "Kari's Scorpion Pages" (On-line). Accessed August 26, 2004 at http://angelfire.com/tx4/scorpiones.

Miller, G. 1988. A Field Guide to Wildlife in Texas and the Southwest. Austin: Texas Monthly Press, Inc..

Milne, L., M. Milne. 1980. The Audubon Society Field Guide to North American Insects and Spiders. New York: Chanticleer Press, Inc..

Parker, S. 1982. Synopsis and Classification of Living Organisms Volume 2. McGraw-Hill Book Company.

Stockwell, S. 2/8/96. "Centruroides vittatus (Say, 1821)" (On-line). Accessed 2/15/00 at http://wrbu.si.edu/www/stockwell/du_jour/c_vittatus.html.

Townsend, L. 6/96. "Scorpions in Kentucky" (On-line). Accessed 2/15/00 at http://www.uky.edu/Agriculture/Entomology/entfacts/struct/ef633.htm.