Two Tints! Araneus spiders – Araneus diadematus


I wanted to share with you photos of two spiders I photographed recently. Location: San Juan Island, WA. Both are in the family Araneidae or what we know as Orb Weavers. The first (orangey one), was observed on a tomato plant July 31, 2021, and the 2nd (brown one) was observed yesterday evening, August 10, 2021, on some sort of wetland grass near my home.

While I knew the orangey one was a Cross Orb Weaver, Araneus diadematus, I wasn’t certain of the brown one’s ID beyond genus Araneus, so I reached out to Seattle Burke Museum’s arachnologist, Rod Crawford to see what he’d say. He responded to my query this afternoon and offered that both are Araneus diadematus spiders. There can be variability in color tint (many of us know the Cross Orb Weaver A. diadematus as pumpkin orange).

Rod continued with, “the ventral view of the brown one shows it is penultimate (still one molt to go). Once they mature they will be more noticeable. Seattle specimens are at this same stage now.” He also offered in terms of color variants among spiders, …”I imagine there is a genetic component to this variation, at least in most cases, but I’ve never looked into the details. I have found situations where spiders living amidst a population explosion of green leafhoppers all tended to be greenish in color, presumably derived from their food.”

It’s all so very interesting, isn’t it! I’m glad we have scientists who are willing to share their knowledge and experience. Thanks to Rod for his help!

Araneus diadematus (San Juan Island 07.31.2021)
Araneus diadematus (San Juan Island 07.31.2021)
Araneus diadematus (San Juan Island 07.31.2021)
Ventral View – penultimate molt – Araneus diadematus (San Juan Island 08.10.2021)
Araneus diadematus (San Juan Island 08.10.2021)

To learn more about spiders, be sure to stop by Rod’s website, Spider Myths – Everything that ‘everybody knows’ about spiders is wrong! https://www.burkemuseum.org/collections-and-research/biology/arachnology-and-entomology/spider-myths

Thanks for reading!

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