Hydnobius autumnalis 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 : 24-25

Hydnobius autumnalis Peck & Cook , new species

( Figs. 2 , 28 , 55–61 )

Type material. Holotype, ♂: CANADA: Ontario: Grenville Co., L 3C6 Wolford Twp., 44°52’03”N 75°43’50”W, 30.X–6.XI.2005, J. Cook, FIT, mature mixed forest ( CMNC) . Paratypes (16): CANADA: Ontario: Grenville Co .: ♂, 2♀♀, same data as holotype except 26.X–2.XI.2003 ( JCIC) ; 2♀♀, 5–12.X.2003 ( JCIC) ; ♀, 26.IX–3.X.2004 ( JCIC) ; ♀, 21–28.IX.2003 ( JCIC) ; ♀, 25.IX–2.X.2006 ( JCIC) ; ♀, Kemptville , 24.X–2.XI.1983, J. Denis, FIT ( CNCI) ; ♀, same locality, 11–25.X.1983, L. Dumouchel, FIT ( CNCI) ; ♂, same locality, Flint Hill for., 9–16.X.1984, B.R.I. staff, Malaise trap ( CNCI) ; Leeds-Grenville Co.: ♂, 7 km SE Westport , N 44°37.727’ W 76°21.545’, 1–31.XI. 2005, 134 m, S. Peck, 4 maple sugarbush FITs ( SBPC) ; ♂, same data except 1–30.IX.2005 ( SBPC) ; [County not indicated]: ♀, Chaffeys Locks , QUBS, 5.X.1980, S. Peck, Ber. for. litter w / fungi ( SBPC) ; ♀, Stittsville, D.A. Smith’s woods, 18.X–11.XII.1979, S. Peck, forest Malaise trough ( SBPC) ; ♂, same data except 1–7.X.1979 ( SBPC) .

Diagnostic description. Body reddish brown, shining. Length of pronotum + elytra = 2.2–2.7 mm (males), 2.2–3.2 (females). Head irregularly, sparsely punctate. Pronotum widest anterior to middle, sides rounded, basal angles strongly obtuse; ratio length:width = 1:1.4; punctation fine to very fine, no visible microsculpture. Elytra wider than pronotum, ratio length:width = 1:0.8; stria 1 clearly impressed, remaining striae punctate, intervals finely punctate, transversely striolate. Antennal club ( Fig. 55 ) moderately broad, ratio club width:length = 1:2.6; width ratio of antennomeres 7:8:9 = 1.4:1:1.8. Mandibles ( Fig. 56 ) moderately elongate; right mandible bidentate apically, with a median 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. 58 ) with large tooth on posterior margin before apex; posterior margin basal to tooth may be irregularly crenulate; female unarmed. Protibia of male weakly widened apically, of female slender. Male mesotibia ( Fig. 57 ) slender, inner margin weakly curved, with lobe at apex, may be serrulate before apex; female mesotibia slender, straight. Metatibia slender in both sexes. All tibiae of both sexes with outer margin spinose. Male. Aedeagus ( Fig. 59 ) with median lobe broad, narrowing in apical one-half to sub-apical obtuse angulation and angulate apex. Parameres straight, concave medially in apical one-half, with two apical setae. Female. Coxites ( Fig. 61 ) elongate, cylindrical, with apical and subapical setae; styli short, inserted at apices of coxites. Sternite 8 ( Fig. 60 ) rounded apically, anterior apophysis broadly triangular.

Distribution. The species is known to occur only in the Mixedwood Plains ecozone of eastern Ontario, Canada ( Fig. 28 ).

Field notes and habitats. Adults have been collected only in mature mixed forest in flight intercept traps and once in a malaise trap and by sifting forest litter with fungi.

Seasonality. Adults have been collected only in September to November, with most specimens (11) in October.

Etymology. The epithet autumnalis (Latin, pertaining to autumn) refers to the September–November seasonality of adults of this species.

Figures

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

FIGURES 1–4. Sogdini, habitus photos. 1. Triarthron lecontei, total length 3.4 mm. 2. Hydnobius autumnalis, total length 3.0 mm. 3. Stereus arenarius, total length 3.4 mm. 4. Sogda obtusa, total length 3.4 mm.

FIGURES 55–61. Hydnobius autumnalis. 55. Right antenna, dorsal view. 56. Mandibles, dorsal view. 57. Male right mesotibia. 58. Male right metafemur. 59. Aedeagus, dorsal view. 60. Female sternite 8, ventral view. 61. Female coxites and styli, ventral view. Scale bar = 0.3 mm (Figs. 55, 59, 61), 0.4 mm (Figs. 57, 58, 60), 0.5 mm (Fig. 56).