Insect Insights, a Bi-Weekly Buford Blog by Karen Richards

The western calligrapher is a small fly that looks like a bee. You can tell it’s not a bee because the eyes are large and close together and because it has two wings, not four. 

These flies are fairly common, and they like to get nectar and pollen from all kinds of flowers. For that reason, they act as pollinators. 

Toxomerus genus flies are beneficial in other ways as well: The larvae eat aphids and don’t damage plants, and the adults, like all flies, don’t sting. 

The common name is perfect, as it describes the finely etched pattern on the abdomen. The markings aren’t easily visible without magnification. One of my first macro photos revealed a western calligrapher’s design, and it definitely propelled me to get back outside with my camera and see more. 

I’ve read the coloring is determined by the temperature when the fly is in the pupal stage (they spend the winter as larvae). If it was warmer, the yellow / orange area is more dominant; if it was colder, there will be more black. It does seem like this year’s flies are darker. 

Although it’s a large genus, there are only two species of Toxomerus in Oregon. The western calligrapher is Toxomerus occidentalis. The other species, Toxomerus marginatus, has similar markings, but the pattern doesn’t wrap around the abdomen at all, and in fact it has a “margin” of yellow-orange around the black. 

Stay curious!

See more of Karen’s work here.

Sources:

Nice overview of the Toxomerus genus: https://focusonnatives.com/calligrapher-flower-flies-are-great-beneficial-insects/. Accessed 4/6/23. 

The Wikipedia entry on the genus is informative: https://en.wikipedia.org/wiki/Toxomerus. Accessed 4/26/23.