Friday, August 7, 2009

Gnat Ogre

This super tiny robber fly in the genus Holcocephala is found throughout the eastern portion of the United States. There are three species within this genus and all of them are located East of the Rockies. Measuring 1/2 inch or less they are the smallest robber flies encountered in their range. The wide set eyes is a key characteristic of these flies and distinguishes them from any other robber flies. They are often referred to as Gnat Ogre's because of their diet, which consists almost entirely of gnats. Look for them in grassy open areas where they will perch on small stems or twigs waiting for dinner to pass by, and with the huge populations of gnats I'm sure they have no trouble whatsoever in finding plenty to eat. Start looking for them now during the mid summer months, when their numbers increase. Keep in mind their small diminutive size when searching for them, they would be easy to pass by without ever knowing they are there.


  1. Great shot of the eyes in the enlarged version.

  2. I clicked on the image...Great shot! I got a good robber fly shot a week or so ago but have been having trouble getting a good ID. One person at Bug Guide suggested a genus and species and I will tentatively go with that. They are tough to ID!

  3. Marvin--Thank you very much, I love robber flies their eyes are great.

    Moe-- Thank you very much. I agree robber flies are hard to ID. They all look so similar. They are some of my favorites to photograph though, yesterday i noticed a robber fly eating a thread waisted wasp. I went to get the camera to capture the moment and it was gone by the time I returned.