Robberfly - Archilestris magnificus
Santa Cruz County, Arizona, USA
October 3, 2007
Size: At least 2 inches
Hands down, the largest robberfly I've ever seen. I saw another photo of one, here on Bugguide, that was hanging upside down by one leg while feeding on a wasp. Shortly before I photographed this one, I observed it in the same position feeding on a honey bee.