Department of Entomology
Entomological Notes

Araneus marmoreus

The genus Araneus has about 1,500 species worldwide, making it the largest of all the spider genera. Araneus marmoreus is found throughout all of Canada to Alaska, the northern Rockies, from North Dakota to Texas, and then east to the Atlantic. It is one of our showiest orbweavers.

Description

Adult female marbled orbweavers are 9 to 20 millimeters in length with very large abdomens that are mostly orange with brown to purple markings and spots of pale yellow. Occasionally the abdomens are nearly white in color. The cephalothorax is yellow to burnt-orange with a central dark line and dark lines down either side. The femora and patellae are orange. The other leg segments are yellow, becoming brown at the distal ends, as are all of the legs of the males.

Life History/Behavior

The webs are found in trees, shrubs and tall weeds, and grasses in moist, wooded settings and can frequently be found along the banks of streams. The webs are oriented vertically and have a “signal” thread attached to the center that notifies the spider when prey has been captured. Unlike the Argiope garden spiders, Araneus marmoreus hides in a silken retreat to the side of the web (at the end of the signal thread). In adults, the retreat is made of leaves folded over and held together with silk. Immature spiders make their retreats out of silk only.

Egg cocoons, which contain several hundred eggs, are generally deposited in October and are constructed of white silk formed in a flattened sphere. Immature spiders emerge from the cocoons in spring. Adults are seen from midsummer until the first hard freeze of fall.

Medical Importance

Authored by: Steve Jacobs, Sr. Extension Associate

March 2002 Revised 2006

This publication is available in alternative media on request.

References

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.

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.

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. Vol. LXXVIII (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.

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.

DISCLAIMER

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Where trade names are used, no discrimination is intended and no endorsement by The Pennsylvania State University or Pennsylvania Department of Agriculture is implied.

Entomological Notes are intended to serve as a quick reference guide and should not be used as a substitute for product label information. Although every attempt is made to produce Entomological Notes that are complete, timely, and accurate, the pesticide user bears the responsibility of consulting the pesticide label and adhering to those directions.

Issued in furtherance of Cooperative Extension Works, Acts of Congress May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture and the Pennsylvania Legislature. D. Jackson, Director of Cooperative Extension, The Pennsylvania State University.

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