|Photos by (not of) Marty Horowitz 9/26/2013|
This guy looks like it grew out of the frost-damaged end of the cactus arm. Not as pretty and popular as its dragonfly cousins, the robber fly is a similarly effective predator. In fact, it counts dragonflies among its prey!
Marty sends more info from this site:
The name "robber flies" reflects their notoriously aggressive predatory habits; they feed mainly or exclusively on other insects and as a rule they wait in ambush and catch their prey in flight. ... Asilidae [robber flies] prey on formidable species including stinging Hymenoptera [wasps,bees, ants], powerful grasshoppers, dragonflies and even other Asilidae, in fact practically anything of a suitable size. (emphasis mine)
And I say therefore: Watch your back!