~120 spp. in 6 genera in our area (72 spp. of Lonchaea
and 36 of Dasiops
; >500 spp. in 8 genera total(2)
Most larvae live behind bark of dead trees; some live on decaying fruits or vegetables.
Some feed on larvae of bark beetles.
Click on an image to view the life cycle:
Mostly saprophagous - the larvae feed on dead or damaged plants, although some also feed on live, healthy plants. Several species of lonchaeids form swarms near or above trees, hovering and milling around in the air. This behavior is common in several families of flies (midges, black flies, dance flies, etc.), but lonchaeids are one of the few groups of "higher" flies (calyptrates and acalyptrates) that do it.(Comment by Terry Wheeler)
Some can be considered beneficial