|Humpback Orb Weaver Spider - Eustala sp.|
Family Araneidae - Orb-Weavers. This tiny orb weaver has some sort of parasitic larvae living behind its head. Live spiders photographed in the wild at Oregon, Illinois.
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This tiny (5mm) unfortunate spider has become host to some sort of parasitic larva - can you see the white, worm-shape on top of the cephalothorax under the overhang of the abdomen? Some have suggested it may be a mantid larva or perhaps some sort of wasp larva. It could be a parasitic fly in the family Syrphidae, Tachinidae, or Phoridae (the flies that infect the domestic honey bees). I will visit her every day and maybe see what happens. (She disappeared 2 days later.)
This from the Atlantic magazine online: "Consider Polysphincta gutfreundi, a parasitic wasp that grabs hold of an orb spider and attaches a tiny egg to its belly (sic). A wormlike larva emerges from the egg, and then releases chemicals that prompt the spider to abandon weaving its familiar spiral web and instead spin its silk thread into a special pattern that will hold the cocoon in which the larva matures. The “possessed” spider even crochets a specific geometric design in the net, camouflaging the cocoon from the wasp’s predators."
Orb weavers comprise a huge family of spiders, with 3500 species worldwide, 180 of which call North America home. These spiders vary greatly in color and size, measuring 2 - 30mm (1/16 -- 1 1/4") long. They have eight eyes arranged in two horizontal rows of four eyes each.
The oldest fossil record of an orb-weaver is from the Lower Cretaceous. Several fossils provide direct evidence that the three major orb weaving families; Araneidae, Tetragnathidae and Uloboridae evolved about 140 million years ago.
Another orb-weaver, another parasite. This is getting ridiculous!
Class Arachnida / Order Araneae: Spiders are the largest group of arachnids. They are easily recognized by their eight legs, and there are few creatures great or small that elicit such irrational fear in mankind. The vast majority of spiders are completely harmless and offer beneficial services, chief of which is keeping the burgeoning insect population in check. I am continually amazed at the resourcefulness of these supremely successful predators.
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