Macrohydnobius simulator (Brown, 1932) 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 : 40-41

Macrohydnobius simulator (Brown, 1932) , new combination

( Figs. 108–114 , 115 )

Hydnobius simulator Brown, 1932a: 6 ; Hatch, 1957: 24.

Type material. Hydnobius simulator , holotype, male, in CNCI; bearing white label “Creston, B.C. / 19.XI.1930 / G. Stace Smith”; white label [male symbol]”; and red handwritten label “ HOLOTYPE / Hydnobius / simulator / No. 3281 Brown”; seen and dissected. Type locality; Creston, BC.

Additional material examined. We examined 158 specimens (See Appendix).

Diagnosis. Body reddish brown to dark reddish brown, shining. Length of pronotum + elytra = 3.1–4.4 mm (males), 3.2–4.0 mm (females). Head irregularly punctate, shining. Pronotum narrow, widest at basal onethird, sides obtusely angulate at basal one-third, basal angles obtuse; with a pair of small basal impressions joined by an irregular row of punctures, punctures within a narrow impression laterally, impression obsolete medially; ratio length:width = 1:1.3; finely punctate, with no microsculpture. Elytra elongate, slightly wider than pronotum, ratio length:width = 1:0.6; with 9 closely punctate striae, stria 1 impressed, striae 6 and 7 do not reach apex; intervals with three classes of punctures: fine punctures usually arranged in single rows, larger scattered punctures on uneven intervals, and (in males only) minute punctures throughout. Antennal club ( Fig. 108 ) slender, ratio club width:length = 1:4.1; width ratio of antennomeres 7:8:9 = 1.2:1:1.4. Mandibles ( Fig. 109 ) elongate, broad at base, narrow apically; lacking teeth on outer margins; left mandible with two teeth on inner margin of apical half; right mandible with a single tooth on basal half of inner margin. Metatrochanter lacking a tooth before apex. Profemur and mesofemur of both sexes unarmed, posterior margin of male metafemur serrulate, female metafemur unarmed. Male protibia ( Fig. 110 ) broad at apex, outer margin spinose; elongate, sinuate spur inserted before apex; female protibia less broad, outer margin spinose; with unmodified apical spur. Mesotibia and metatibia of male apically widened, spinose; of female slender, spinose. Male. Aedeagus ( Fig. 111 ) with median lobe elongate, broad, apical one-half evenly tapering to apex. Parameres inserted at basal one-third of median lobe, reaching apical one-fourth of median lobe, straight with outwardly angled apices; paramere apices thin, concave on inner margin; small notch on lateral lamina below paramere base. Female. Coxites ( Fig. 113 ) elongate, cylindrical, with elongate setae throughout length; styli inserted at apices of coxites. Sternite 8 ( Fig. 112 ) weakly emarginate apically; anterior apophysis broadly triangular.

Variation. Flight wing dimorphism occurs in both sexes of this species. Of 158 specimens examined for this character, 43% (48% of males, 40% of females) have flight wings reduced to narrow flaps about one-third elytron length. Metepimeron of a single male specimen with an apparent stridulatory file ( Fig. 114 ); this structure was not found in females and was absent in all other males.

Distribution. The species occurs in northwestern North America ( Fig. 115 ). We have seen specimens from Canada: the provinces of Alberta and British Columbia; USA: the states of Idaho, Montana, Washington.

Field notes and habitats. There are few data. Most specimen labels explicitly state that the specimens were collected on snow, with 68 on snow at Creston, BC, from November to January. Three specimens were collected in flight intercept traps and one in a funnel trap.

Seasonality. Adults have been collected through the cooler months from September to March, with the greatest number in December.

Figures

FIGURE 115. Known western North American localities of Macrohydnobius simulator (black dots).

FIGURES 108–114. Macrohydnobius simulator. 108. Right antenna, dorsal view. 109. Mandibles, dorsal view. 110. Male right protibia. 111. Aedeagus, dorsal view. 112. Female sternite 8, ventral view. 113. Female coxites and styli, ventral view. 114. Male right metepimeron showing possible stridulatory file, lateral view, elytron removed. Scale bar = 0.3 mm (Fig. 113), 0.4 mm (Fig. 112), 0.5 mm (Figs. 109, 111), 0.75 mm (Fig. 108), 1.0 mm (Figs. 110, 114).