Identified by Eric Fisher, only saw two of these, they're about 1cm long or less, I just happened to spot it on a rock.
This is a Robber Fly in the family Asilidae. They are very accomplished hunters and can be very large, over 3cm!
Mating pair of Efferia at the sand dunes in New Mexico
This was finally ID'd as an Efferia
Here's a pretty robber fly that I found at the top of Bootjack Trail at Muir Woods. ID'd by Eric Fisher
This is a female robber fly in the subfamily Laphriinae, though it's not as fuzzy as many of them are. ID'd by Eric Fisher
This beautiful bee-mimic Robber Fly was one of the insect highlights of my Florida trip. The hunter has become the hunted in this photo. The prey is an adult Assassin Bug in the genus Pselliopus.
This large male is a species of Laphria, thought which one it is can't really be determined from a photo. ID'd by Eric Fisher
Eric Fisher kindly identified this for me as a Lestomyia species of Robber Fly. It's not possible to ID further without the specimen and he said it might be undescribed!
Another M. occidentalis, ID'd by Eric Fisher
This big robber fly was quite cooperative since he was eating. This photo turned out better than some of the other Robbers, getting them in perfect focus isn't easy (this isn't perfect either)
This is an undetermined Machimus, ID'd by Eric Fisher
This isn't a bee, but actually a Robber Fly. The Asilids of the genus Mallophora strongly resemble bees in the genus Bombus. They actually prey on them as well. This is a mating pair, though the second one is out of focus
Here's another image of this neat Robber Fly
This is a tiny robber fly and really cute. He was very cooperative. Found him hawking around sand palm scrub in Florida
Another shot of this cute little robber
This is a very tiny robber fly eating an even smaller fly. It was ID'd by Dr. Eric Fisher (as are most of these Cali robbers). It was found in the Sierran foothills of Pollock Pines.
This is the best find from my Lake Tahoe trip. Dr. Eric Fisher ID'd this as Pogonosoma ridignsi and said that it's not very common. It's in the subfamily Laphriinae. This is also one of the cuter robbers I shot.
This is a large robber fly in the genus Proctacanthus. Posed long enough for a decent shot.
Here's a cool Robber Fly from South Florida. Subfamily Asilinae
This large robber fly (Promachus hinei) is feeding on a male Eastern Pondhawk. This perhaps one of my all time best photos! Certainly my best "other insects" photo
Robber Flies are so cool
A large Promachus sp robber fly.
This female robber fly is actually laying her eggs on the tip of a blazing star.
This is some southwestern species of Promachus. Not sure which
This amazing fly was at least 3cm long. This individual was munching on a Honey Bee and was very cooperative about me taking its photo.
This giant Robber managed to snag a Blue Dasher dragonfly, I've also see one with a Common Whitetail
This big Robber is a female Stenopogon cazieri, identified by Eric Fisher.
Another genus of Robber Fly that I found at Lake Tahoe National Forest