The Zig Zag Web

Yellow garden spider female with prey (photo by Kate St.John)
Yellow garden spider female with prey, Virginia Beach, 5 Sept 2017 (photo by Kate St.John)

Last week in Virginia Beach my mother said, "Come see my spider."  We stepped out the front door and there she was, an impressive yellow garden spider with a zig zag web.

Yellow garden spiders (Argiope aurantia) are very common orb weavers but we rarely notice them until late summer when the females have reached full size, about an inch long.   At this point their webs are also large with conspicuous vertical zig zags(*) giving them this alternate name in Virginia: the sewing machine spider.

My mother's spider hid behind her web which in turn was camouflaged by the light colored brick behind it.  (Click here to see a more obvious zig zag.)  In these photos the spider is packaging prey in gauze or perhaps eating it.

Yellow garden spider with prey (photo by Kate St.John)
Yellow garden spider with prey (photo by Kate St.John)

My mother pointed out a smaller web nearby with a smaller spider in it, only 0.2 to 0.3 inches.  It was the male who will eventually come courting, but he has to be very careful and quick.  His goal is to deliver both sperm packages without being attacked.  After delivering the second one he dies a natural death.  Then the female eats him.

Soon the female will lay 500 to 1,000 eggs in a small brown sac which will overwinter and hatch in early spring.  The tiny spiderlings are cannibals, too, but those who survive will play out the same story next year.

If you find a yellow garden spider you can enjoy it in peace.  Even though the females are large, they won't bite unless you grab them (egads!) and their venom is harmless to humans.

Read more about these and other Pennsylvania native spiders in this fact sheet from Penn State.

 

(photos by Kate St. John)

(*) The zig zag is called a stabilimentum.

2 thoughts on “The Zig Zag Web

    1. Kathy, I think these spiders are especially prevalent in Virginia. Most of the photos I found on the Internet were taken in southern Virginia.

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