Papestra biren
(Goeze, 1781)
Glaucous Shears, Glaucous Shears Moth
Papestra biren, commonly known as the glaucous shears, is a noctuid with a wingspan of 30–38 mm. The was first described by Goeze in 1781 and exhibits notable color variation across its range, including purplish-grey, ashy-grey, and dark ruddy-grey forms. are active from May to July in a single . The species has a broad Palearctic distribution and was introduced to North America in 1935, where it has since expanded southward from Newfoundland.
Pronunciation
How to pronounce Papestra biren: //pəˈpɛstɹə ˈbaɪɹɛn//
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Identification
Distinguished from similar noctuids by the combination of purplish-grey forewings with blackish suffusion, pale grey stigmata with whitish rims edged black, and dark brownish fuscous hindwings. The bluish-grey or glaucous tint of the typical form is characteristic. In North America, range overlaps with Papestra quadrata; separation requires examination of genitalia or detailed wing pattern analysis. The various named color forms may cause confusion with other grey noctuids, but the stigmata pattern remains consistent.
Images
Appearance
Medium-sized noctuid with wingspan 30–38 mm. Forewing purplish-grey suffused with blackish, with pale grey stigmata bearing whitish rims edged with black. Submarginal line whitish, preceded by black dentate marks. Hindwing dark brownish fuscous. Exhibits color : typical form shows bluish-grey tint; 'lappo' form is ashy grey with pale stigmata (Lapland, Finland, northern Ireland); 'aperta' is exceptionally dark; 'taunensis' is uniform dark ruddy grey with only external margins of claviform and pale.
Habitat
Montane and submontane , rising to 2200 m above sea level in the Alps. Associated with low-growing vegetation in mountain environments. In introduced North American range, occupies similar cool, moist habitats with suitable plant availability.
Distribution
Native to most of Europe (absent from southern Iberian Peninsula, Italy, and Greece). Extends through the Palearctic: Kashmir, Siberia, Central Asia, Amur, Kamchatka, Russian Far East, and Japan. Introduced to Newfoundland in 1935; subsequently expanded southward in North America, now overlapping with native Papestra quadrata in parts of its range.
Seasonality
on wing from May to July. Single per year ().
Diet
Larvae feed primarily on Vaccinium uliginosum (bog bilberry) and Vaccinium myrtillus (bilberry), both low-growing mountain Ericaceae. Additional recorded include Salix caprea (goat willow) and Sorbus aucuparia (rowan). feeding habits not documented.
Host Associations
- Vaccinium uliginosum - primary larval plantbog bilberry, low-growing mountain plant
- Vaccinium myrtillus - primary larval plantbilberry, low-growing mountain plant
- Salix caprea - secondary larval plantgoat willow
- Sorbus aucuparia - secondary larval plantrowan
Life Cycle
Holometabolous. stage not described. Larva brownish red with dark reticulation; dorsal line distinctly paler; lines formed of dark lunules meeting in dark patch on 11th segment, with 12th segment yellowish beyond; lateral lines yellowish white; white with black edges. presumably in soil or leaf litter; pupal stage undescribed. emerge May–July. Single .
Behavior
activity. Larvae feed on low-growing vegetation. No other documented behavioral traits.
Ecological Role
Herbivore in montane and submontane . Larval feeding on Vaccinium contributes to nutrient cycling in mountain heath and shrub . Role as prey for not documented.
Human Relevance
No documented economic or medical significance. Subject of entomological study due to color and successful North American introduction. Used as indicator of montane conditions in Europe.
Similar Taxa
- Papestra quadrataOverlapping range in North America; requires genitalia or detailed wing pattern examination for separation
- Other grey NoctuinaeSimilar general appearance; distinguished by specific stigmata pattern and hindwing coloration of P. biren
More Details
Color polymorphism
Four named forms recognized: typical form with bluish-grey tint; lappo (ashy grey, pale stigmata, northern regions); aperta (exceptionally dark); taunensis (dark ruddy grey, Taunus Mountains).
Introduction history
Deliberately or accidentally introduced to Newfoundland in 1935, representing a rare case of successful transoceanic establishment by a noctuid . Subsequent southward expansion demonstrates ecological flexibility.
Taxonomic history
Originally described as Phalaena biren by Goeze in 1781; later transferred to Papestra.