Acsala

Males distinguished by broad wings and small size; females by flightless, narrow-winged condition. Larvae identifiable by barbed setae. Distinguished from other Lithosiini by the combination of male diurnal activity, female flightlessness, and subarctic distribution.

Adult males have broad wings with a wingspan of 27–28 mm. Adult females possess narrow, reduced wings (stenopterous condition). Wing venation is variable. Larvae have barbed setae. Freshly laid eggs are red-orange, later turning pale orange.

Rocky environments supporting lichen growth. Associated with substrates bearing black foliose and crustose lichens.

Western subarctic North America: Alaska (United States) and Yukon (Canada).

Larvae feed on rock-growing lichens, specifically black foliose and crustose forms. Documented food sources include species of Buellia, Lecidea, Orphniospora, Parmelia, and Umbilicaria.

• Buellia - foodlichen genus
• Lecidea - foodlichen genus
• Orphniospora - foodlichen genus
• Parmelia - foodlichen genus
• Umbilicaria - foodlichen genus

Eggs deposited in single layer on underside of rocks in batches up to thirty. Incubation period eight to ten days.

Adult males are day-active with weak flight. Adult females are flightless and spend much time under rocks. Eggs are laid in batches on rock undersurfaces.

Larval herbivore on saxicolous lichens. Role in nutrient cycling in subarctic rocky ecosystems.

• Other LithosiiniAcsala distinguished by female flightlessness (stenopterous wings), male diurnal activity, and specific subarctic distribution. Most Lithosiini have fully winged females and broader distributions.

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life