Stomion laevigatum

Finston, Terrie L. & Peck, Stewart B., 2004, Speciation in Darwin’s darklings: taxonomy and evolution of Stomion beetles in the Galápagos Islands, Ecuador (Insecta: Coleoptera: Tenebrionidae), Zoological Journal of the Linnean Society 141 (1), pp. 135-152 : 149-150

STOMION LAEVIGATUM GR WATERHOUSE

Stomion laevigatus Waterhouse, 1845: 30 . Type locality: [Galápagos] probably either Isabela Island (Tagus Cove) or Santiago Island (Bucaneer Cove). Lectotype here designated with our red rectangular label, in BMNH. Sex unknown; from syntype series, right antenna missing segments 9–11, all tarsi of left side broken and missing left metathoracic leg; with round blue label: syntype; rectangular label: 3614; rectangular label: Stomion laevigatus /Wat. Type 3614; rectangular label: F. Bates 81-19; folded label: laevigatus/ Galápagos Is. Waterhouse 1877: 82. Mutchler 1925: 228, 236; 1938: 9. Blair 1928: 672; 1933: 477. Van Dyke 1953: 77. Kaszab 1970: 189. Franz 1985: 93.

Stomion bauri Linell 1898: 263 . Type in USNM. Type 1322 (examined). Type locality: southern Isabela Island (= Albemarle). Mutchler 1925: 236. Blair 1933: 477.

Stomion laevigatus santacruzensis Franz 1985: 113 . Type in Franz collection, NHMW (examined). Type locality: Santa Cruz Island, Tortuga Bay, 8 June 1975, leg. H. Franz ( Franz 1985: 93). New synonymy.

Diagnosis: Length 6–8 mm, width 3–4 mm; overall body surface smooth and somewhat shiny, 2.1¥ longer than wide; fine sparse punctures on pronotum and elytra; pronotum strongly convex at the apex; pronotum widest at middle, roughly the same width at the base as at the apex, constricted slightly at the base, 1.5–1.6¥ wider than long; elytra smooth with fine but distinct irregularly arranged punctures; sides of abdomen parallel; dorsal tooth on right mandible present, moderately well developed.

Distribution: Widespread. Fernandina (Cabo Hammond), Isabela (Punta Garcia, Tagus Cove, Urvina Bay, Volcan Alcedo, near Villamil), Santa Cruz ( Tortuga Bay) and Santiago (Cerro Cowan, James Bay, Playa Espumilla, Los Guayabillos) Islands. Also Cowley, Daphne Major and Caamano islets.

Bionomics: The species occurs from the littoral up to the humid forest zone, from sea level to 500 m on Volcan Wolf and 1100 m on the summit of Volcan Alcedo, both on Isabela. Collected at many sites, and in all months from January to August. Examined: 521 specimens.