Cremastocheilus tomentosus

One of about forty-five species of myrmecophilous Cremastocheilus.

Identification
DIAGNOSIS. Frontoclypeal transition tumid, clypeus slightly less than one- third as long as pronotum, with tomentose "bar" at each side of carina; posterior pronotal angles blunted; dorsal faces of mesepimera flattened; elytra with discal punctures small, ovate, only vaguely annular; pygidium short-tomentose in basal half.

Distribution
Gisela, Arizona

Biology
Ant host unknown

Description
DESCRIPTION. Holotype male, length 13.0 mm, width at elytral humeri 6.0 mm. Body elongate, piceus, legs reddish. HEAD weakly convex, shallowly depressed at each side above antennal insertions, nearly contiguously punctate everywhere except clypeus and medial impunctate area on occiput, punctures small; eyes rather small, dorsal interocular width slightly more than three times maximum transverse diameter of eye, ocular canthi not prominent, extending nearly to center of eye; frontoclypeal transition tumid (rounded), tumosity extending anteriorly at midline to form rounded medial carina; clypeus transverse, about one-third as long as pronotum, lateral margins acutely rounded, apical margin strongly reflexed, disc with large transverse bar of thick, cream- colored tomentum on each side of medial carina. Antennal scape boot-shaped from dorsal view. Mentum cupuliform, pentagonal, anterior margin transverse, tumid; lateral angles nearly right; posterior angle slightly obtuse; disc nearly impunctate. PRONOTUM one and two-thirds times wider than long, about three-fourths as wide as elytra, widest slightly behind middle; lateral margins posteriorly arcuate, anteriorly straightening and rapidly converging to anterior angles; anterior angles small, not breaking line of lateral margins, free from anterior margin; posterior angles rather large, lobiform, extending posterolaterally free from disc; disc declivous in basal third and lateral fifths (steeply so above posterior angles), irregularly punctate, punctures shallow, small but varying widely in size, mostly separated by own width or less, very sparse near anterior and posterior margins. SCUTELLUM extending to about basal fourth of elytra, moderately punctate, punctures round, weakly annular, larger than pronotal punctures, with posterior margins effaced. MESEPIMERA each dorsally flattened, from dorsal view nearly as long as posterior pronotal angles, impunctate. ELYTRA one and one-third times longer than wide, lateral margins weakly converging to apical truncation; disc flattened, sparsely punctate, punctures ovate, weakly annular, smaller than larger pronotal punctures, sep- arated by one to five or more times their own widths. PYGIDIUM subsemicircular, basal half short-tomentose; apical half polished; basal angles rounded; disc moderately punctate, punctures deep, round, more dense and larger in tomentose portion. VENTER with proepisternites and mesosternite sparsely vaguely punctate; metepisternites and lateral portions of metasternite densely lunately punctate, punctures becoming smaller and sparse near midline on metasternite; abdominal venter basomedially flattened; ab- dominal sternites sparsely lunately punctate, punctures smaller than metepisternal punc- tures. LEGS with front femora each with posterior face densely punctate, anterior face shallowly cariose-punctate; front tibiae bidentate in apical third, insertion of spur nearly even with distal margin of proximal tooth, anterior face scabriculous-punctate, proximal tooth with distinct carina running perpendicularly from near ventral margin to apex of tooth. Middle and hind femora each moderately lunately punctate, densely so near apex; dorsal margins of hind femora rather strongly arcuate; middle tibiae with strong U-shaped carina at distal two-fifths, from anterior view distinctly narrowing below carina, apex with anteroventral spine twice as long as anterodorsal spine; hind corbel dorsal of tarsal insertion deeply cupuliform, elliptical, inner margin of cup longer than outer margin; front and hind tarsi slightly shorter than their respective tibiae, middle tarsi equal in length to middle tibiae.