The hover fly (also commonly called the flower fly) is one of our most often misidentified backyard residents. When one suddenly appears out of nowhere and hovers close to our face while making a buzzing sound, many panic and begin swatting at it fearing it is a bee or yellowjacket. Actually, the hover fly is not a bee, not a yellowjacket, nor hornet or wasp. Instead, it is a fly and is harmless to humans.
Here is how you can tell if you have encountered a stinging insect or a hover fly. All you have to do is remember this brief saying, “Two wings fun, four wings run.” In other words, flower flies possess only one pair of wings, whereas yellowjackets and their relatives have two sets of wings. In addition, while the flower fly will not sting or bite, as we all know, bees, yellowjackets, wasps, and their kin are armed with a stinger that they will use to inflict a painful sting.
In addition, most of the flower flies we encounter in our backyards look much like yellowjackets. However, if you will look closely, you will notice the hover abdomens of flower flies look deflated and flat. The abdomens of yellowjackets, on the other hand, appear inflated.
Also, hover flies can both hover and fly backwards, whereas, yellowjackets do not possess this mastery of the air.