Robber Fly

I caught this robber fly (Diptera: Asilidae) with my camera a few days ago. 

Robber flies are predators of a lot of other insects. They aren't particular about what they eat, if they can catch it they'll eat it. They sit and wait for prey to fly by and then attack them on the wing. 

They kill their prey by injecting them with a toxic saliva. The robber fly's mouthparts fit together to form the proboscis that they use to inject the saliva. Robber flies can be distinguished from other similar flies by the distinctive notch on the top of their heads between the compound eyes. There is a great deal of variation in body shape, size, and color among the species of Asilidae. For example, some robber fly species are excellent mimics of wasps or bees, which helps protect them from predators. Robber fly larvae can be found in the soil or in decaying wood where they feed on the larvae of other insects.
In the garden, robber flies are generally considered beneficial predators of pests. However, they are not picky about diet choices and will sometimes be seen eating other beneficial insects such as honey bees, wasps, spiders, and even other robber flies.