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Argiope aurantia
A fairly large, black, white and yellow spider with an alien design on its back found in a nest along a hiking trail (near Lake Blanche). Distinctive yellow and black markings on their abdomens and a mostly white cephalothorax. Males range from 5–9 mm (0.20–0.35 in) females from 19–28 mm (0.75–1.1 in). Like other members of Argiope they are considered harmless to humans.
Wetlands, between prairie and lake shore, near Lake Blanche in Glendalough State Park, Minnesota. Often build webs in areas adjacent to open sunny fields where they stay concealed and protected from the wind. The spider can also be found along the eaves of houses and outbuildings or in any tall vegetation where they can securely stretch a web. The circular part of the female's web may reach two feet in diameter. Webs are built at elevations from two to eight feet off the ground. Female Argiope aurantia spiders tend to be somewhat local, often staying in one place throughout much of their lifetime.
The web of the yellow garden spider is distinctive: a circular shape up to 2 feet (60 cm) in diameter, with a dense zigzag of silk, known as a stabilimentum, in the center. In a nightly ritual, the spider consumes the circular interior part of the web and then rebuilds it each morning with fresh new silk. The radial framework and anchoring lines are not usually replaced when the spider rebuilds the web. The spider may be recycling the chemicals used in web building. Additionally, the fine threads that she consumes appear to have tiny particles of what may be minuscule insects and organic matter that may contain nutrition
No problem! I don't know of any birds that specifically prey on these spiders, and I am inferring their bright color suggests they are inedible to birds and other insects, like a warning sign. I think they are fairly short-lived, but you may want to confirm that fact! To me, the stabilimentum looks fairly circular, which suggests this is a juvenile, but you may want to look into that more too. This one is defnitely a female, as well.
J-Thank you so much!!! I'd seen similar spiders on trips to Costa Rica (Osa Peninsula) and Kauai Hawaii but never in Minnesota let alone, north-western Minnesota. I was thrilled to read they're "harmless to humans" as the two I found in Glendalough were very very large. This is the second one I found. The first one (images to come) had a much more distinct zigzag pattern in her "stabilimentum" so I believe (based on what I read) that this is a younger female and the other was a more mature one... :-)))) The first one I found either moved farther in-field, away from the hiking trail, or was eaten as I saw her every day for a week and then she was gone. Two weeks later I found this one, in a different area but in the same general location of the first. I would have loved to get images of them catching something in their web and or mating with their much smaller mate but the second one disappeared as well after only seeing it twice. Do you know if there's a bird or something that preys on these spiders? They disappear almost as fast as I find them...Argh! "-)
Spotted on Aug 18, 2012
Submitted on Aug 30, 2012
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