Hydnobius acarinus Peck & Cook, 2009

Peck, Stewart B. & Cook, Joyce, 2009, Review of the Sogdini of North and Central America (Coleoptera: Leiodidae: Leiodinae) with descriptions of fourteen new species and three new genera, Zootaxa 2102 (1), pp. 1-74 : 22-24

Hydnobius acarinus Peck & Cook , new species

( Figs. 51 , 52–54 )

Type material. Holotype, ♂: UNITED STATES: California: Kern Co.: River Kern, 19.IX.1979, Robert Gordon ( USNM) . Paratypes (1): UNITED STATES: California: ♂, with same data ( USNM) .

Diagnostic description. Body light reddish brown, shining. Larger than H. kiseri , length of pronotum+elytra = 2.7–2.8 mm (males). Head irregularly punctate. Pronotum widest near middle, sides rounded, basal angles obtusely rounded; ratio length:width = 1:1.4; finely punctate with faint reticulate microsculpture. Elytra wider than pronotum, of medium length, ratio length:width = 1:0.7; stria 1 clearly impressed, remaining striae punctate, interval punctures similar to strial punctures, transverse strioles present.

Antennal club ( Fig. 52 ) moderately slender, ratio club width:length = 1:3.4; width ratio of antennomeres 7:8:9 = 1.3:1:1.7. Right mandible bidentate, with a submedian tooth; left mandible with tooth on apical one-half of inner margin. Mesoventrite lacking a median longitudinal carina (diagnostic character for separating this species from H. kiseri ). Profemur and mesofemur of male unarmed; male metafemur ( Fig. 53 ) with large tooth before apex of posterior margin. Male protibia widened apically; mesotibia with inner margin weakly sinuate, lobed at apex; metatibia ( Fig. 53 ) angulate on inner margin near basal one-third, apical two-thirds widened. All tibiae spinose on outer margin. Male. Aedeagus ( Fig. 54 ) with median lobe broad, narrowing to acute apex. Parameres narrow, outwardly curved, with two apical setae. Female. Unknown.

Distribution. The species is known only from the type series ( Fig. 51 , star).

Field notes, habitats, and seasonality. The two specimens were probably collected at night at a uv light trap when daytime conditions were sunny, dry, and mild as normal for this dry region of the Sierra Nevada mountains in September (R. Gordon, pers. comm.).

Etymology. Named with reference to the lack of a mesoventral carina, which separates this species from the closely related H. kiseri .

Figures

FIGURE 51. Known western North American distribution of Hydnobius kiseri (black dots) and H. acarinus (black star).

FIGURES 52–54. Hydnobius acarinus. 52. Right antenna, dorsal view. 53. Male right metafemur and metatibia. 54. Aedeagus, dorsal view. Scale bar = 0.3 mm (Fig. 54), 0.4 mm (Fig. 52), 0.5 mm (Fig. 53).