Stomion obesum

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

STOMION OBESUM EC VAN DYKE

Stomion obesum Van Dyke, 1953: 74 . Holotype: type 7385 in CAS (examined). Type locality: Pinzón (= Duncan) Island. Label data: 14–15.VII.1906. F.X. Williams. Franz, 1985: 93.

Stomion galapagoensis pinzoni Franz 1985: 113 . Type in Franz collection NHMW (examined) . Type locality: Pinzón Island , summit. Label data: June 1975, Franz leg. New synonymy .

Diagnosis: Length 7–9 mm, width 3–5 mm; body broad and convex, 2.0–2.1¥ longer than wide; pronotum slightly transverse, 1.5–1.6¥ wider than long, coarsely punctured, some punctures near margins elongate, pronotum widest at middle, nearly as wide at base, sides rounded; elytra with parallel ridges, single row of weak punctures between ridges; thorax very convex, sides rounded; dorsal tooth on right mandible present, well developed.

Distribution: On the widely separated, small, low islands of Pinzón, Santa Fe and Tortuga. Seemingly limited to small satellite islands south of or between Santa Cruz and Isabela.

Bionomics: The species occurs in the littoral and arid zones of these small and low islands, from sea level up to 240 m on Pinzón, under litter and rocks. Adults have been collected in February, from May to July, and October to December. Examined: 150 specimens.