a family of insects of the order Mecoptera. Length, 2–6 mm. The head is elongated in a bill shape. The wings in females are reduced; in males they are hook-shaped processes. The eggs are laid in autumn on mossy mounds; the larvae are white, C-shaped, and up to 8 mm long. The pupa lives free. There are two genera, with 15 species; the USSR has approximately ten. Insects of the genus Boreus are common in the European part of the USSR; they appear on the snow, near places covered with moss, when there is a thaw.