If you’re going to nurture wildflowers and plant flowers to help the native bees, it doesn’t make sense to kill them. Unfortunately pesticides are only chemicals, and they’re not smart enough to know which bugs not to kill. Fortunately, a nice bonus that comes of planting for bees is that many of the same flowers also attract syrphid flies.
There’s a whole host of syrphid flies. Like tiny bees, they often hover near the flowers, darting from side to side, hovering some more, and finally settling down. These are hover flies, or flower flies. Most of them are predators as larvae, feeding on such popular pests as aphids. As adults they are pollinators.
Hover flies are especially fond of small, flat-faced flowers like Buttercups and Strawberries. Another excellent plant for flower flies is that old garden standby, Sweet Alyssum. Right now, the number one flower that I have for syrphid flies is coriander. Every morning, they’re all over it. As for wildflowers, they like Goldenrod as much of the bees, but in midsummer they love Daisy fleabane.
Not all syrphid flies are predators. Some look too exactly like honeybees or bumblebees. The bee mimics more often spend their larval period in murky water. (Like my tub garden, I think.) So they’re interesting pollinators, but if you’re looking for pest control, watch for hover flies.