I'm suspect this post is giving someone the heebie jeebies. I sure jumped when I came across these critters. I found a few female Yellow Garden Spiders, Argiope aurantia, members of the orb weavers (I just love that name!), working on their captured dragonflies. The males are about one third the size of the females.
In this closeup of an above shot is visible a spinneret with web strand coming out.