Akalyptoischion diadeletron Hartley, Andrews & McHugh, 2008

Hartley, Christopher S., Andrews, Fred G. & Mchugh, Joseph V., 2007, A Taxonomic Revision Of The Genus Akalyptoischion Andrews (Coleoptera: Latridiidae), The Coleopterists Bulletin (mo 6) 61, pp. 1-50 : 21-22

Akalyptoischion diadeletron Hartley, Andrews & McHugh new species ( Fig. 18 )

Etymology. Greek meaning ‘‘distinct abdomen’’ referring to the unique abdominal foveae of this species.

Description. Length 1.25–1.30 mm. Width 0.35–0.40 mm. Body elongate, subparallel, uniformly reddish brown; head and pronotum with very short setae, elytra glabrous; head short, narrower than pronotum by one eye width, sides slightly sinuate; head foveae very shallow, indistinct, small; head setation even, setae very short and decumbent; head punctation irregular, conspicuous on pointed specimen, surface rugose; eyes small and not prominent with 4 facets; tempora 3/4 eye width; hind angles rounded, greater than 90u; clypeal fovea length of antennomere III, 0.6 times width of labrum; labrum anterior margin slightly emarginate; mandible apex pointed with an apical tooth and 3 small subapical serrations, prostheca short; antennae with a 3-segmented club; antennae reach posterior 1/3 of pronotum; antennomere I irregular, anterior face arcuate, posterior face with a strong point, II slightly elongate, oval, III small, straight sided, length equal to width, IV–VIII submonilliform gradually increasing in size, IX–XI form club, IX wider than long, oval, X slightly larger than IX, slightly flattened, XI straight sided, elongate trapezoid.

Pronotum subquadrate, equal width throughout; anterior angles 90u but rounded, lateral margin subparallel; lateral margin slightly explanate with,14 small tubercles each bearing a microscopic seta; median 2/3 raised with very short decumbent setae, width of raised area not decreasing posteriorly; pronotal foveae distinct, shallow, both anterior and posterior pair connected medially by a shallow furrow; pronotal punctation dense but irregular, conspicuous on pointed specimen, surface rugose.

Elytra subparallel, lateral flange weak, present in anterior 1/3 only; 6 striae; humeral angle a sharp, acute lobe; strial interspaces 1, 3 and 5 raised, 5 raised slightly higher than others; all interspaces glabrous; epipleuron complete, narrowing posteriorly.

Ventral surface subglabrous; submental fovea deep, length of antennomere IV, smooth with few micropunctures; ventral head punctation dense over entire head; gular punctation dense; prosternum evenly punctate; mesosternum without sharp carinae; metasternum with a single fovea between mesocoxae, a large, irregular fovea posterior to each mesocoxa, a large, arcuate fovea anterior to each metacoxa, and median surface with scattered punctures; abdominal ventrite I with 2 prominent carinae on outer edges of intercoxal process, 2 vague foveae bounded by carinae at anterior corners of intercoxal process, a large, irregular fovea equal in size to metacoxae posterior to each metacoxa, and median surface with few scattered punctures at midline only; ventrites II–IV lack typical basal depressions, each ventrite bears 3 pairs of punctures, one pair medially and one pair laterally to each side of the body; lateral pairs vague, circular; median pairs with a distinct border medially, laterally fading into ventrite surface.

Material Examined. HOLOTYPE, USA: label data: ‘‘OR: Harney Co. 13 mi N, 3 mi E Burns VI-13-1972 5,0009 ex Mtn. Mahogany duff E. M. Benedict’ ’ ( CDAE).

PARATYPES, USA, same data as holotype (1, CDAE); ‘‘OR: Harney Co. 13 mi N Burns VI-13-72 5,0009 Ellen Benedict’ ’ on slide (1, CDAE) ;

Additional Material, ‘‘ Boise Co., ID Burn Crk 14-13-1977 5,0009 A. J. Allen funneled from Ponderosa duff’’ handwritten label (1, CDAE); ‘‘ IDAHO: Boise Co. , Idaho City 10-mile campground 20.VII.1982,’’ ‘‘ponderosa litter A. Allen’ ’ (1, FMNH) .

Diagnosis. This species may be known from all others by the carinae on abdominal ventrite I and the unique, foveate basal depressions on abdominal ventrites II–IV ( Fig. 18 ). The foveae that occur in the basal depressions of ventrites II–IV are only apparent on slide-mounted specimens. The basal depressions of ventrites II–IV are not completely obliterated but rather interrupted by each pair of foveae. The carinae on the intercoxal process of ventrite I are visible on pointed specimens. The densely punctate, quadrate pronotum with the raised median portion not decreasing in width posteriorly and the subglabrous body are also distinctive. Carinae are also found on ventrite I of A. gigas , but A. diadeletron is immediately distinguishable from that species by its small size, and the characters given above.

Figures

Figs. 17–18. 17) A. atrichos, male, abdominal ventrites; 18) A. diadeletron, abdominal ventrites.