San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide
Araneus andrewsi adult female. Photo copyright Jim Berrian
Adult female

Araneus andrewsi
Orb Weaving Spiders

ARANEIDAE

Description

Female Araneus andrewsi generally measure 11-22mm. The carapace is brown and darker on the sides. The abdomen has a pair of anterior humps and is tan to black in coloration. It also has a folium. The total length of males is 8-11mm. Although their color and appearance is similar to the female, males are perhaps not as robust. As in most araneids final diagnosis should rely on an inspection of the genitalia.

Range and Habitat

Araneus andrewsi occurs along the west coasts of Oregon, California and northern Baja California. These spiders can be found in a variety of situations and habitats. They have been observed in basements and on walls, boulders, and large tree trunks.

Related and Similar Species

Similar in size to Araneus gemma but Araneus andrewsi can be distinguished on basis of color pattern and genitalia.

References

Levi, H.W. 1971. The diadematus group of the orb-weaver genus Araneus north of Mexico (Araneae: Araneidae). Bull Mus. Comp. Zool. 141(4):131-179

Dondale, C.D., J.H. Redner, P. Paquin, and H.W. Levi. 2003. The Insects and Arachnids of Canada, Part 23. The orb-weaving spiders of Canada and Alaska (Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae). NRC Research Press, Ottawa, Ontario, Canada. 371pp.

Text by Jim Berrian. Photo © Jim Berrian.

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