Maintaining a healthy flower garden involves multiple tasks, including insect identification. Pest management in the garden is often easier when the beneficial insects can be differentiated from the potential trouble makers. Most of the types of flower flies that appear in the garden from season to season get listed as beneficial insects. Fortunately, those same flies can be identified as members of the Syrphidae family, better known as Syrphid Flies.Their often colorful bodies resemble bees and wasps. Many species feed on aphids and other plant pests. Coupled with the fact that they also perform pollination tasks, flower flies break the traditional fly mold and place them squarely in the beneficial insect category.
But wait, there’s more to the story of flower flies. For example, the straight answer to the syphrid fly question, do they bite, is a resounding no. They hover and fly and nectar on flowers, and they do not bite or sting.
In spite of their benefits, based on statistical trends, there’s little possibility of a surge in interest among individuals hoping to photograph all the flower files they see in the hope that one of those pictures might go viral. With those caveats in mind, the following section provides some basic rules of thumb for anyone and everyone interested in learning about flower fly identification for the garden. Here’s a general outline of the group along with pictures of representative species.
Flower Fly Species
Syrphid fly identification through pictures is possible, and it follows similar identification rules as other insects. Most of the flower fly groups, be they families or genera, share similar looking thoracic and abdominal patterns. With a few species, eye color and face color can be a good ID clues. Those basic identification starting points are generally good enough to get started identifying any flower fly using a picture.
Sometime a picture does not provide enough information. A few species, for example, have a distinct hair pattern on the abdomen, something a camera does not always catch. In other cases, a close up of the wing pattern is needed for accuracy.
Probably the easiest way to begin identifying flower flies is by dividing them into two large groups. The Eristalinae consist of approximately 500 North American species and the the Syrphini consists of approximately 300 species. The picture at the top of the page shows what is common called a drone fly, one species in the Eristalis genus. Eristalis tenax, for example, is a very common drone fly species, found throughout North America.
The picture at the top of this section shows a syphrus fly, the namesake for both the family and tribe. Syrphus populations abound along both North American coasts, making them some of the most common syrphid species in high population residential areas. The gold thorax and the yellow and dark abdominal stripe pattern tend to help start the identification.
A rounded and distinctly patterned abdomen provide the first ID clues for all Syrphus species Comparing and contrasting the abdominal pattern provides a next good ID step.
Thin Bodied Flower Flies
A group of flower flies can also be initially identified by their thin abdomen. Sphaerophoria, a long name for a genus of often small, thin syrphid flies, consists of some sixteen different species. The picture shows a spaerophoria species. Their body patterns change from male to female as well as among the species.
A few additional syrphid genera, Toxomerus, for example, also are characterized by their diminutive size and thin bodies.
The final two pictures show some representative species from the genus They share the physical train of having vertical markings on the abdomen, rather than the horizontal stripes on the abdomen as shown in the syphrus species.