Orchard Spider on its web

This spider has made a sort of half-orb web on our back deck. It is less than half and inch long, so I almost missed it. It is, I think, a species of Leucauge, probably L. argyra, or the very similar L. venusta. Its common name is Orchard Spider. Leucauge is Greek for “with a bright gleam”. Darwin only named one spider, and Leucauge is it. The species name, venusta, is Latin for charming, elegant, or beautiful.

Orchard Spider

A closer look reveals it brilliant colors. Orb-web spiders are almost completely blind, so it is not obvious to me why this creature is so brilliantly colored.