Syrphid Fly

Syrphid Fly, Eristalis stipator, on stiff greenthread, Thelesper

Photo by: Bryan Reynolds

Eristalis stipator

The term “Syrphid fly” applies to a great many flies and not a single species, composing the insect family, Syrphidae. This family can be broken down into 3 subfamilies which encompass 3,000 species. This family is also known as “hoverflies” or flower flies, which speaksto their fondness for nectar and pollinating capabilities. The adults have a simple diet of pollen and nectar, while the larvae have a diverse diet. Larvae may consume decayed or decomposingplant and animal matter (wet wood, rotting plants) or on insects themselves. Females may lay up to 100 eggs in a single brood. In most cases, the site will be chosen because of its proximity to a soft-bodied insect population, such as aphids. The number of eggs laid is greatly dependenton the presence of prey.

There are few characteristics that all species of this family share—depending on the species, the morphology of the fly can either be slender or stout. Syrphidae are usually covered in bright yellow and black hair. Spots and stripes are not uncommon. Larvae are either creamy white or green. Members of this family have a single pair of functional wings, while a smaller setfurther down the thorax and abdomen helps them maintain their balance. Typically, this family ranges between 10 and 20 millimeters long.

This family is so common it can be found worldwide, and certainly in North America, where it is recognized as a deterrent to aphid populations, which damage crops. Therefore, Syrphid flies are prized in agriculture. To attract this family, plant a diversity of flowering plants. Syrphidae favor flowers such as asters, daisies, marigolds, sunflowers, and zinnias, among others. In order to accomplish their pollination and nectar-gathering, Syrphidae have a unique flight pattern. They are known to hover, and then suddenly fly to a new position. While frequenting flowers, this family can easily be mistaken for bees. Syrphidae are also distinct frombee flies because their proboscis is not as long or prominent. Neither are their legs. Their faces also have noticeable bumps. This family also exhibits unique wing venation.

Written by: Robert Gibson, an undergraduate Environmental Studies student at the University of Oklahoma