Hydnobius pumilus LeConte, 1879

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 : 14-17

Hydnobius pumilus LeConte, 1879

( Figs. 22–27 , 28 )

Hydnobius pumilus LeConte, 1879: 511 ; Hatch 1957: 26.

Hydnobius latidens LeConte, 1879: 512 ; Horn 1880: 282, 317. Type material. Lectotype of H. pumilus here designated to ensure the name's proper and consistent application, male, in MCZC, LeConte collection; bearing white label “Veta Pass / 1.7 Col”; white label male symbol; white handwritten label “267”; red and white label “Type / 3159”; white handwritten label “ H. pumilus / LeC.”; white handwritten label “latidens 2”and our red lectotype label; seen and dissected. Type locality: South Veta Pass of the Union Pacific Railroad, at border of Huerfano and Costilla Counties, Colorado.

Hydnobius latidens described from unique specimen which becomes the holotype, here designated, male, in MCZC, LeConte collection; bearing white label “Ant”; white label male symbol; red and white label “Type / 3158”; handwritten white label “ H. latidens / LeC.; and our red holotype label; seen and dissected. Type locality: Anticosti Island , Quebec, Canada. Synonymized by Hatch (1929: 11) .

Additional material examined. We examined 119 specimens (See Appendix).

Diagnosis. Body reddish brown, shining. Small, length of pronotum + elytra = 1.8–2.3 mm (males), 1.7–2.2 mm (females). Head finely, irregularly punctate. Pronotum widest at basal one-third, sides rounded, posterior angles obtuse; ratio length:width = 1:1.4; finely punctate with faint reticulate microsculpture. Elytra short, wider than pronotum, ratio length:width = 1:0.8; stria 1 clearly impressed; remaining striae punctate, confused; interval punctures slightly smaller than strial punctures; intervals transversely striolate. Antennal club ( Fig. 22 ) moderately broad, ratio club width:length = 1:2.8; width ratio of antennomeres 7:8:9 = 1.2:1:1.4. Mandibles ( Fig. 23 ) moderately stout; right mandible bidentate apically, with a submedian tooth on inner margin; left mandible with a tooth on apical one-half of inner margin. Profemur and mesofemur of both sexes unarmed; male metafemur ( Fig. 24 ) with large tooth on posterior margin before apex, may be irregularly serrulate on posterior margin basal to tooth; female metafemur unarmed. Protibia and mesotibia of both sexes weakly widened apically; metatibia narrow in both sexes. All tibiae of both sexes spinose on outer margin. Male. Median lobe of aedeagus ( Fig. 25 ) broad, with acute apex. Parameres broad, apical one-half concave medially, with two apical setae. Internal sac with flattened setae with acute apices. Female. Coxites ( Fig. 27 ) moderately elongate, cylindrical, with apical and subapical setae; small styli inserted at apices of coxites. Sternite 8 ( Fig. 26 ) rounded apically; anterior apophysis truncate apically.

Nomenclatural notes. For reasons of stability, we follow the usage of Hatch (1929: 11, 1957: 26) in accepting Hydnobius pumilus as the prefered name, which he probably based on the principle of page priority, and not the usage of Horn (1880: 317) as the first reviser, who treated H. pumilus LeConte as the synonym of H. latidens LeConte with no discussion or explanation. The female specimen from "San Mateo, California ", in the LeConte series of H. pumilis is actually a specimen of H. kiseri Hatch.

Distribution. The species occurs across northern North America from New Brunswick to central Alaska and in the northern contiguous United States from Wisconsin to Colorado to Oregon ( Fig. 28 ). We have seen specimens from Canada: the provinces of Alberta, British Columbia, Manitoba, New Brunswick, Ontario, Quebec and Yukon territory; USA: the states of Alaska, Colorado, Montana, Oregon, Washington, Wisconsin, and Wyoming.

Field notes and habitats. Adults have been collected in forested habitats, by evening car netting, flight intercept traps, and on occasion in pitfall traps.

Seasonality. Adults have been collected from May to September, with most specimens in July and August.

Figures

FIGURE 28. Known North American localities of Hydnobius pumilus (black dots) and H. autumnalis (open squares).

FIGURES 22–27. Hydnobius pumilus. 22. Right antenna, dorsal view. 23. Mandibles, dorsal view. 24. Male right metafemur. 25. Aedeagus, dorsal view. 26. Female sternite 8, ventral view. 27. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Figs. 23, 25–27), 0.4 mm (Fig. 22), 0.5 mm (Fig. 24).