Cross Orbweaver Spider

The cross orbweaver was probably introduced from Europe. This showy orbweaver is commonly encountered next to buildings with exterior lighting.
Cross Orbweaver Spider - Articles

Updated:

Mohammed El Damir, Bugwood.org

Araneidae—Orbweavers

(Araneus diadematus)


Araneus diadematus immature. Photo by Steven Jacobs, Penn State Extension

The cross orbweaver was probably introduced from Europe, where it has been studied at some length. While a showy orbweaver, it is commonly encountered on or next to buildings with exterior lighting, including lighted stairwells of structures in more rural settings. It is known from Pennsylvania north throughout New England, throughout Canada, and then south into Washington and Oregon.

Description

Adult females range in length from 6.5 to 20 millimeters, and the males are 5.5 to 13 millimeters long. The color varies greatly from specimen to specimen. Generally, the smaller and/or younger individuals are darker, while the adult females are lighter. The background color is yellow to brown with two wavy or scalloped longitudinal lines (folium). There are several white or yellow spots within and around the folium. Four elongated spots appear toward the anterior end of the abdomen, creating what appears to be a cross. As with the banded garden spider, the carapace has three dark longitudinal lines or bands.

Life History/Behavior

The adults are found from late summer through autumn. In late September, the females leave their webs and seek out protected locations to deposit between 300 to 900 eggs. The eggs are enclosed within a cocoon of yellow, silken threads, shaped in a hemisphere. Typical egg deposition sites include under the bark of dead trees and in cracks and crevices.

Medical Importance

Verified bites by this species are reported to produce a range of symptoms, including pain, swelling, and redness. Systemic reactions include anxiety, nausea, headache, and muscle cramps, but not all individuals have the same reactions. Symptoms/reactions can last from two days to three weeks.

Reference

Baerg, W. J. 1936. The Black Widow. Ark. Agr. Expt. Sta. Bul. 325. 34 pp.

Baerg, W. J. 1959. The Black Widow and Five Other Venomous Spiders in the United States. Ark. Agr. Expt. Sta. Bul. 608. 43 pp.

Bradley, R. A. 2013. Common Spiders of North America. University of California Press. 271 pp.

Breene, R. G., et al. 2003. Common Names of Arachnids. 5th ed. The American Arachnological Society Committee on Common Names of Arachnids. 42 pp.

Gertsch, W. J., and F. Ennik. 1983. “The spider genus Loxosceles in North America, Central America, and the West Indies (Araneae, Loxoscelidae).” Bul Amer Mus. Nat. Hist. 175: 24–360.

Herms, W. B., and M. T. James. 1961. Medical Entomology. 5th ed. The Mac-Millan Company, New York. 616 pp.

Howell, W. M., and R. L. Jenkins. 2004. Spiders of the Eastern United States: A Photographic Guide. Pearson Education. 363 pp.

Isbister, G. K., and M. R. Gray. 2003. “Effects of envenoming by comb-footed spiders of the genera Steatoda and Achaearanea (Family Theridiidae: Araneae) in Australia.” J. Toxicol. Clin. Toxicol. 41: 809–819.

Kaston, B. J. 1948. “Spiders of Connecticut.” Conn. State Geol. Nat. Hist. Survey. Bull. 70. 874 pp.

Kaston, B. J. 1972. How to Know the Spiders. 3rd ed. Wm. C. Brown Company, Dubuque, Iowa. 272 pp.

Levi, H. W. 1959. “The Spider Genus Latrodectus (Araneae, Theridiidae).” Trans. Amer. Microscopical Soc. 78(1): 7–43.

Long, D., R. Snetsinger, and K. F. Helm. 1995. “Localized Pruritic Rash Due to Recurrent Spider Bites.” J. Geriatr. Dermatol. 3(6): 186–190.

McKeown, N., R. S. Vetter, and R. G. Hendrickson. 2014. “Verified spider bites in Oregon (USA) with the intent to assess hobo spider venom toxicity.” Toxicon 84: 51–55.

Authors