Lachesilla pedicularia
(Linnaeus, 1758)
cosmopolitan grain barklouse, cosmopolitan grain psocid
A small barklouse (1.5–2 mm) with near-global distribution. Frequently but brachypterous forms occur. Distinguished by abdominal brown stripes, hairless forewings, and characteristic wing venation. Found on tree bark, in stored grain, and human structures. Member of the pedicularia group within Lachesillidae.
Pronunciation
How to pronounce Lachesilla pedicularia: //læˈkɛsɪlə ˌpɪdɪkjʊˈlɛəriə//
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Identification
Distinguished from by: (1) with brown stripes; (2) forewings completely hairless; (3) wing R1 meeting wing edge at nearly right angle; (4) brown markings on several wing veins. Female subgenital plate forms simple curved shape. Male hypandrium bears simple (non-forked) appendages. Genital characters require microscopic examination.
Appearance
Small, brown-coloured insect measuring 1.5–2 mm in length. Wing dimorphism common: typically (long-winged) but brachypterous (short-winged) individuals occur. marked with brown stripes. Forewings hairless. Wing R1 meets wing margin at approximately a right angle. Several wing veins marked with brown.
Habitat
Primary on trunks and branches of deciduous and coniferous trees including beech, birch, broom, oak, pine, spruce, and yew. Secondary occurrences in anthropogenic environments: haystacks, straw bales, stored grain, barns, houses. Recorded from bird nests (robins).
Distribution
distribution spanning Europe, North Africa (Algeria, Egypt, Morocco, Tunisia), Middle East (Israel, Turkey, Armenia), North America (Canada, USA, Mexico), South America (Argentina, Chile, Colombia), Asia (China, India, Japan, Malaysia, Mongolia, Nepal, Taiwan), and Oceania (Australia, Hawaii, Micronesia).
Host Associations
- Fagus - trunks and branches
- Betula - trunks and branches
- Cytisus scoparius - trunks and branches
- Quercus - trunks and branches
- Pinus - trunks and branches
- Picea - trunks and branches
- Taxus - trunks and branches
- Turdus migratorius - nests
Human Relevance
Pest of stored grain products. reflects association with stored cereals and anthropogenic environments including barns and houses.
Similar Taxa
- Other Lachesilla speciesDistinguished by combination of abdominal striping, hairless forewings, R1 angle, and genital ; many lack these specific character states
More Details
Wing dimorphism
Both fully winged () and reduced-wing (brachypterous) forms occur within , a common but not universal trait in Psocodea.
Taxonomic history
Originally described by Linnaeus in 1758 as Hemerobius pedicularius, later transferred to Lachesilla. Basionym reflects early placement in Hemerobiidae (lacewings).
Species group affiliation
Member of the pedicularia group, characterized by males possessing a single clunial ; this has been subject to recent taxonomic revision in the Neotropics.