What's That Bug? does not endorse extermination

Hi Daniel,
I sent the attached photographs to you some time ago and I never heard back so I assume they were lost. I’m still curious about the spiderlings, however, and I wonder if you have any thoughts. The pictures were taken in late May on our deck in southwest Oregon in a madrone/oak forest. Based on Bug Guide pictures, the spiderlings might be an Argiope or an Araneus species, but the adult looks like a jumping spider. When the adult appeared, the spiderlings ignored it, although they would respond by moving rapidly if I so much as blew lightly on them. I suspect that the adult is too small physically to be the mother and produce that number of eggs but, if I’m right, then what is it, and why weren’t the spiderlings frightened by it? It just doesn’t make any sense to me. I enjoyed the back and forth between you and Johanna and her nails. Your website is interesting, informative and fun, all at the same time, and I read it regularly. Thanks for your help.

Hi Bob,
You are correct that your spiderlings are Orb Weaver Spiderlings, probably Argiope or Araneus species. The adult spider is an Antmimic Spider in the genus Castianeira, probably Castianeira cingulata.

What's That Bug? does not endorse extermination
Location: Oregon

One Response to Orb Weaver Spiderlings and Antmimic Spider

  1. Alexis says:


    The adult spider is highly likely a Sergiolus columbianus, I found them native to my home town in Kennewick, WA. First found one in 2001 as a child and found at least two a year in my home, took years for me trying to identify. Finally Identified them in 2013. Even had one as a pet for about 108 days as a child. Interestingly, weeks before her passing she laid a small clutch of pink eggs. Sadly they did not last by my own error as a gnat managed to get in and laid its eggs on hers; larva devoured them. Still a beautiful spider! Its one of my favorite spider native to Pacific North West. =)

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