The European Garden Spider
Rebekah Beyer - GS201H - Fall 2010
All images courtesy of http://commons.wikimedia.org/wiki/Araneus_diadematus
Identification and distinguishing characteristics
|The European garden spider, or cross spider, is an oft-seen resident of the WOU campus. Also known as the diadem spider or cross orbweaver, European garden spiders are easily identified because of their distinctive white abdominal markings, arranged like a cross. Adult European garden spiders range in size from 6.5 to 20 millimeters for females 5.5 to 13 millimeters for males. The spiders range in color from light golden-red to deep gray, and have long darkly-banded legs. Newly hatched spiders are bright yellow with a single black mark on the abdomen, but change color with maturity (“Garden Spider”). The females build complex orbital webs up to 40 cm in diameter, using self-produced sticky silk (“Cross Spider”).|
Reproduction and life-cycle
Adult spiders emerge throughout late summer an autumn. Like many spider species, male garden spiders must approach females cautiously and risk being eaten by their mates (Borror). After mating, the male retreats and the female isolates herself; after a number of days, she deposits somewhere between 300-900 eggs in a well-protected silk cocoon and dies shortly after. The hatchlings emerge in spring, gathering together in great clumps. After their first molt, the young spiders will disperse by “ballooning” (“Garden Spider”).
Habitat and geographic range
|These large, leggy spiders are most commonly spotted suspended head-down in their impressive orbital webs among brush, buildings, and trees. European garden spiders can tolerate a wide range of habitats, including fields, gardens, forests, and urban areas. Lighted entryways and buildings provide exceptional habitat, as the light naturally attracts flying insects late in the evening. European garden spiders are found throughout Europe, the northern half of the United States and the southern provinces of Canada (“Cross Spider”). It is not native to the Americas, and was likely brought over from Europe (Jacobs).|
Biotic & abiotic interactions
The European garden spider is a predator, preying on other insects. The webs effectively entangle small flying insects, which are immediately paralyzed and wrapped in silk by the residing spider. Every evening, the garden spider will devour its entire web – and subsequent insects – and spin a new one before morning (“Cross Spider”).
Though intimidating to look at, the European garden spider has a mild bite that is harmless to humans. To date, humans do not harvest or utilize European garden spiders for any specific function. They do not specifically contribute to any medicinal purposes (Jacobs), except that spiders’ webs can be used to help staunch bleeding wounds. European garden spiders are not endangered, and no specific conservation efforts exist on their behalf (“Garden Spider”).
The European garden spider is an impressive specimen, especially the larger females. I encountered one of these spiders while on campus, and I determined that knowing more about them would likely ease my trepidation at a future encounter.
Other interesting information
http://srs.britishspiders.org.uk/portal.php/p/Summary/s/Araneus+diadematus – Cool graphs on habitat and range
http://commons.wikimedia.org/wiki/Araneus_diadematus - More amazing photographs
"Araneus diadematus Clerck, 1757". Encyclopedia of Life, available from "http://www.eol.org/pages/1194185". Accessed 30 Nov 2010.
Borror, Donald J. & White, Richard E. Insects. Boston: Houghton Mifflin. 1970. Pg 55.
“Cross Spider.” Nature Mapping Animal Facts. Washington NatureMapping Program. Rev. 2004. Web 20 Nov 2010.
Furniss, R. L. & Carolin, V. M. Western Forest Insects. US Department of Agriculture Forest Service. 1977. Pg 54.
“Garden Spider (Araneus diadematus).” Arkive. Wildscreen: 2010. Web 29 Nov. 2010
Jacobs, Steve. “Cross Orbweaver.” Insect Fact Sheet. PennState College of Agricultural Sciences. Rev. 2006. Web 25 Nov 2010.
< http://ento.psu.edu/extension/factsheets/cross-orbweaver >
Ludy, C. & Lang, A. “Bt maize pollen exposure and impact on the garden spider, Araneus diadematus.” Entomologia Experimentalis et Applicata: 2006. Pg 145-156