bark louse

• bark-louse

bark louse (plural bark lice)

1. (obsolete) Any insect of the family Coccidae, that infest the bark of trees and vines.
   • 1833 January 20, The New England Farmer and Horticultural Journal, volume 11, page 226:

     Housed plants are considerably injured by an oval bark-louse, the Coccus Hesperidum of Linnæus, which has been introduced from abroad.

2. Any insect of the order Psocoptera, that live on or near trees and feed on algae and lichen.
   • 1999, George O. Poinar, Roberta Poinar, The Amber Forest: A Reconstruction of a Vanished World, page 84:

     Another group of insects that tend to be very secretive in their habits and were very well represented in the ancient forest are the bark lice, or psocids.⁶⁸ Bark lice (90) are usually solitary, but sometimes the adults and nymphs live together under webs spun out of silk emitted from head glands. They are found not only in litter but, as their name implies, on and under bark.

   • 2002, Lance A. Durden, Gary R. Mullen, “1: Introduction”, in Gary R. Mullen, Lance A. Durden, editors, Medical and Veterinary Entomology, page 8:

     These include springtails (order Collembola), bark lice (order Ps[o]coptera), […] .

   • 2010, P. J. Gullan, P. S. Cranston, editors, The Insects: An Outline of Entomology, 4th edition, page 479:

     When present the wings are membranous, with reduced venation, with the hind wing coupled to the larger fore wing in flight and at rest, when the wings are held roof-like over the abdomen (as shown here for the bark louse Amphigerontia contaminata (Psocidae); after Badonnel 1951).

Used as a synonym of scale (short form of scale insect) in the vernacular name of certain scale insect species (superorder Coccoidea).

• (any species of order Psocoptera): bark fly, psocid

• book louse
• scale insect