BARKFLIES AND BOOKLICE (PSOCOPTERA)
S.M. Turk Updated by K.N.A. Alexander
Although amongst the least known of insects, the Psocoptera are actually abundant in the countryside, especially on trees and shrubs. A steady stream of recent arrivals has brought the national checklist up to 99 species and the Cornish list to 39. There are two distinct groups: those that live out-ofdoors are referred to as barkflies, while those that live inside buildings are known as booklice. The barkfly species are the subject of a new Barkfly Recording Scheme (www.brc.ac.uk/schemes/barkfly) and can be identified using New (2005). No national review has been carried out and so the statuses given below are provisional. Recent arrivals in Cornwall include Atlantopsocus adustus (Hagen) discovered only in 2006 but already widespread on coastal scrub, Trichopsocus brincki (Badonnel), T. clarus Banks, T. dalii McLachlan and Ectopsocus axillaris (Smithers), the last already common on coastal Gorse Ulex sp. scrub before it was first noticed! Some of these recent arrivals raise difficult questions for conservation, with A. adustus globally rare, being otherwise only known from the Canary Islands and Madeira. It is included in the RDB provisionally. The booklice are mostly casual imports, some being recorded only as single specimens in warehouses or ships’ holds. A proportion of these introductions are minor pests of stored products, feeding, it is believed, on minute moulds and mildews, often associated with books, upholstery and foodstuffs (Busvine, 1966). They are particularly common in Cornwall owing to the humidity and one or more species are present in most houses. Probably the commonest species in Cornish houses is Liposcelis bostrychophilus Badonnel. Another, Trogium pulsatorium (Linnaeus), has a ticking call similar to the Death-watch Beetle Xestobium rufovillosum.