Syrphids Back Again

Feb 16, 2010

Have you seen the little syrphid flies, aka flower flies and hover flies, hovering around the early spring blossoms?

We saw half a dozen of them Monday, Feb. 15 nectaring a white ceanothus at the Marshall Post Office in Marin County. The ceanothus is a shrub from the buckhorn family, Rhamnaceae. 

Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the UC Davis Department of Entomology, said these  syrphids (below) are probably from the genus Toxomerus. The family is Syrphidae (flower flies).

The larvae of these insects are good to have in your garden--they eat  aphids, thrips and small caterpillars. The adults feed on nectar and pollen.

The syrphids fly so fast that you almost need a motor drive to capture them in flight. Plus, they seem especially skittish this time of year. Shadow them with your body or camera and they're gone in a flash.

To learn more about flower flies, a good read is Robert Buggs' 25-page booklet, "Flower Flies (Syrphidae) and Other Biological Control Agents for Aphids in Vegetable Crops," published in May 2008 by the University of California, Division of Agriculture and Natural Resources (UC ANR). You can download it for free by accessing this page.

It's illustrated with photos that will help you recognize many of the syrphids.

By Kathy Keatley Garvey
Author - Communications specialist

Attached Images:

A SYRPHID FLY (problably from the Genus Toxomerus) heads toward a white ceanothus blossom near Tomales Bay. (Photo by Kathy Keatley Garvey)

Honing In

WINGS GLITTERING in the sun, a syrphid fly lands on a white ceanothus blossom. (Photo by Kathy Keatley Garvey)