Stomion linelli

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 : 150

STOMION LINELLI KG BLAIR

Stomion linelli Blair, 1933: 478 . Type locality: [Galápagos] either Eden Islet or Santa Cruz (= Indefatigable) Island. Type in BMNH (not examined). Van Dyke 1953: 78. Kaszab 1970: 189.

Stomion mutchleri Blair 1933: 477 . Nomen nudum.

Stomion galapagoensis leleupi Kaszab 1976: 187 . Holotype male and one paratype in KBIN (examined). Type locality: Santa Cruz. Label data: under stones in crater at island summit [Cerro Crocker], locality G 35, 12–17.II.1965, leg. J. & N. Leleup. Franz 1985: 92. New synonymy. Notes. Kaszab (1970: 188) states that his two type specimens could not be distinguished from specimens supposedly collected by J. & N. Leleup in an unspecified locality in continental Ecuador. We agree that they cannot be separated and must conclude that they represent another case of mislabelling, and that S. linelli does not occur on mainland Ecuador.

Diagnosis: Length 7–9 mm, width 4–5 mm; body broad, <2.0¥ longer than wide; overall body surface smooth; fine, sparse punctures on pronotum and elytra; pronotum apical margin nearly straight; pronotum transverse, 1.7¥ wider than long, noticeably narrow at apex and broadening continually toward the base; elytra smooth with punctures very fine, sometimes obsolete, arranged in parallel rows; abdomen broad and convex, giving a robust shape; dorsal tooth of right mandible present, well developed.

Distribution: Widespread as the nominate subspecies ( Figs 32, 33 ) on Baltra, Bartolomé, Beagle, Daphne Major, Eden, Rabida, Santiago, Seymour and South Plazas islands, and as S. linelli leleupi ( Figs 34, 35 ) in the uplands and north slope of Santa Cruz Island. Not Genovesa (Tower) Island.

Bionomics: The species occurs in the littoral and arid zones, on coastal dunes and in mangrove debris and shrub litter and at carrion from sea level to upper transition zone forests at 600 m elevation, on both ash and soil substrates. Adults collected in January, March to July, and November. Examined: 571 specimens.

Figures

Figures 30–35. Scanning electron micrographs of the head and pronotum (18¥), with inset of pronotal disc (300¥) and the elytral disc (100¥). Figs 30, 31. S. laevigatum; Figs 32, 33. S. linelli linelli; Figs 34, 35. S. linelli leleupi.