Monday, July 5, 2010

Yellowjacket Hover Fly

Here’s a neat fly to have show up at a 4th of July picnic. The Yellowjacket Hover Fly, Milesia virginiensis, is a member of the Syrphid Fly family. This family includes a wide range of flies that resemble various bees or wasps. People think this species is a close copy of the common Yellowjacket that frequents food vendors at fairs and carnivals.

The flattened abdomen, held in a down curved position, makes the fly look to be starving. This fly spends a lot of time sitting on low growing vegetation. When disturbed, it takes flight and alternates between stationary hovering and short straight line dashes. It will often hover around the person that disturbed it, sometimes causing a duck-and-flail reaction in people who are trying to ward off what they believe to be a stinging attack.

Yellowjacket Hover Flies are found in the woods or in fields near woods. Their larvae feed on the decomposing heartwood of larger trees, so they tend to stay near the most likely source of this food.

Flies differ from wasps by having only a single pair of wings. Just below the wing is a structure called a haltere that looks like a stick with a ball at the end. The halteres move along with the wings and help to stabilize the fly during flight. The combination of a single pair of wings along with a pair of halteres tells you that you’re looking at a fly.


  1. Steve..thanks for the info...but if he lands on me I am not going to take time to check him out!!! ; } : ]

  2. Fascination info! I love learning so many new things when I visit your site! I'll have to start looking more closely at these little winged friends! ~karen

  3. I just posted the same thing the other day and thought it was a yellow jacket or something that would sting you. I thought it was a yellow jacket.

    It was on my hydrangea bush.

    Scroll down to the third story when you get there, if you go.

  4. grammie g - Most people wait until these flies have been swatted into submission before checking them out.

    Thanks, Karen.

    Hi, Abe. I regularly visit your bird blog, but haven't been to any of the others. I'll check this out. Thanks.