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Cross Orbweaver Spider

Araneus diadematus

Image of female cross orbweaver.

The cross orbweaver was probably introduced from Europe, where it has been studied at some length. This is another one of the showy orbweavers and although it may be found in many of the same areas as the other orbweavers, it is commonly encountered next to buildings with exterior lighting—even occurring in 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 longitudinal, wavy or scalloped 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 previous species, the carapace has three dark, longitudinal lines or bands.

Life History/Behavior

Image of an immature cross orbweaver on a web.

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

A recent report of verified spider bites lists this spider as producing a range of symptoms, including pain, swelling, and redness. Systemic reactions included anxiety, nausea, headache, and muscle cramps, but not all individuals had the same reactions. Duration of symptoms/reactions ranged from 2 days to 3 weeks.

Authored by: Steve Jacobs, Sr. Extension Associate

March 2002 Revised 2015

This publication is available in alternative media on request.

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 MacMillan 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 combfooted 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.

Ubick, D., P. Paquin, P. E. Cushing, and V. Roth, eds. 2005. Spiders of North America: An Identification Manual. American Arachnological Society. 377 pp.

Vetter, R. S., and P. Kirk Visscher. 1998. “Bites and Stings of Medically Important Venomous Arthropods.” International. J. Derm. 37: 481–496.

Vetter, R. S., et al. 2006. “Verified Bites By Yellow Sac Spiders (Genus Cheiracanthium) in the United States and Australia: Where Is the Necrosis?” Amer. J. Trop. Med. Hyg. 74(6): 1,043–1,048.

Vetter, R. S., and G.K. Isbister. 2008. “Medical aspects of spider bites.” Annu. Rev. Entomol. 53: 409–429.

 

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