Stomion helopoides

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 : 146

STOMION HELOPOIDES GR WATERHOUSE

Stomion helopoides Waterhouse, 1845: 30 . Type locality: San Cristóbal Island. Lectotype here designated with our red rectangular label, in BNHM: female from syntype series of two specimens; segments 5–11 missing from left antenna, apical segment of left metatarsus missing; round label with blue edge: syntype; round label: Type; rectangular label: Waterhouse type; folded label: Stomion helopoides ; Galápagos Islands. A third syntype not seen, possibly lost. Waterhouse 1877: 82. Howard 1889: 192. Linell 1898: 263. Mutchler 1925: 236. Blair 1933: 477. Van Dyke 1953: 73. Franz 1985: 93.

Stomion helopioides Linell 1898: 263 (misspelling).

Diagnosis: Length 9–10 mm, width 4–5 mm; body large, broad, 2.0¥ longer than wide, densely punctured but with overall surface smooth; pronotum transverse, 1.5–1.6¥ wider than long, apex deeply concave, broadest at middle, distinctly narrowed at base, punctures coarse, sparse on disc; elytra evenly punctured throughout, striae barely impressed; dorsal tooth on right mandible absent.

Distribution: San Cristóbal Island: various sites around Baquerizo Moreno (Wreck Bay), playa north of Punta Lido, Playa Lobos, Playa at Bahia Rosa Blanca.

Bionomics: In littoral and arid zones, from sea level to 10 m elevation, on beach sand and ash substrates, under litter of beach plants and at sea lion dung. Adults collected January, February and May. Examined: 177 specimens.