Bostrichinae, Latreille, 1802

Zhang, Yi-Feng, Meng, Ling-Zeng & Beaver, Roger A., 2022, A review of the non-lyctine powder-post beetles of Yunnan (China) with a new genus and new species (Coleoptera: Bostrichidae), Zootaxa 5091 (4), pp. 501-545 : 516-518

Key to the species of subfamily Bostrichinae

1 Elytral declivity without 2 strong spines, or if spines present, well separated from suture. Antennal club not flabellate nor with strongly transverse segments............................................................................ 2

. Elytral declivity with 2 strong spines in middle close to or on suture; antennal club flabellate or with strongly transverse segments ( Sinoxylini Lesne )............................................................................... 3

2(1) Intercoxal process of first abdominal ventrite broader and with a flattened ventral face ( Fig. 3B ). Metepisternum more broadly truncate behind with metepimeron widely separated from metaventrite ( Bostrichini Latreille )....................... 12

. Intercoxal process of first abdominal ventrite forming a vertical lamina ( Fig. 3A ). Metepisternum narrowed posteriorly so that metepimeron nearly touches metaventrite ( Xyloperthini Lesne )............................................... 22

3(1) Submarginal carina along lateral margin of elytra curving dorsally at its posterior end to join carina forming lower margin of elytral declivity. Elytral disc angularly separated from declivity ( Fig. 25 )................... Sinoxylon anale Lesne,1897

. Submarginal carina along lateral margin of elytra continues to run parallel to elytral margin to reach suture.............. 4

4(3) Spines on elytral declivity contiguous, inserted on sutural interstriae, triangular, with pointed tips...................... 5

. Spines on elytral declivity not contiguous, inserted lateral to sutural interstriae......................................8

5(4) Frons without a row of four minute teeth ( Fig. 26 ). Large species, 6.5–9 mm long.......... Sinoxylon crassum Lesne,1897

. Frons with a row of four minute teeth. Smaller species, not more than 6 mm long.................................. 6

6(5) Elytral pubescence of the elytra dense, rather long and conspicuous ( Fig. 28 )......... Sinoxylon fuscovestitum Lesne, 1919

. Elytral surface either glabrous, or with very short, inconspicuous pubescence..................................... 7

7(6) Declivital teeth small, sharply pointed, inserted at the middle of the height of the declivity ( Fig. 27 ). First antennomere of club five times as long as wide. Scutellar shield small.................................. Sinoxylon flabrarius Lesne, 1906

. Declivital teeth reduced to a small triangular prominence, inserted below the middle of the height of the declivity. First antennomere of club not more than four times longer than wide. Scutellar shield large, subpentagonal............................................................................................... Sinoxylon cucumella Lesne, 1906

8(4) Spines on elytral declivity laterally compressed. Elytral bases carinate............................................9

. Spines on elytral declivity not laterally compressed, subcylindrical. Elytral bases not carinate................................................................................................. Sinoxylon japonicum Lesne, 1895

9(8) Margin of elytral declivity without costae; base of pronotum with small, rounded granules.......................... 10

. Margin of elytral declivity with three pairs of costae, the uppermost barely distinct or obsolete; base of pronotum with densely placed, flattened granules.............................................................................. 11

10(9) Apical groove of elytra barely widened at the external angle; apical declivity matt, not very abruptly separated from disc granules of posterior area of pronotum very dense; femora black; length ca. 4 mm ............. Sinoxylon pubens Lesne, 1906

. Apical groove of the elytra markedly enlarged at the external angle; apical declivity shining, very abruptly truncate; granules of posterior area of pronotum more widely separated; femora brown or reddish-brown; length ca. 3–3.5 mm ( Fig. 29 ).............................................................................. Sinoxylon pygmaeum Lesne, 1897

11(9) Second antennomere of club relatively long and narrow, ca. 3.6–3.8 × longer than wide; t 4.1-5.1 mm long ( Fig. 30 )................................................................................ Sinoxylon tignarium Lesne, 1902

. Second antennomere of club relatively short and wide, ca. 3.0–3.2 × longer than wide; 3.5-4.3 mm long........................................................................................ Sinoxylon mangiferae Chūjō, 1936

12(2) Elytra with a raised longitudinal costa near base and fascicles of dense golden-yellow hairs scattered over elytral surface ( Fig. 21 )............................................................... Lichenophanes carinipennis (Lewis, 1896)

. Elytra without longitudinal costa near base and scattered fascicles of hairs....................................... 13

13(12) Body rather elongated, 4 to 5 × longer than wide. Anterior margin of pronotum with a row of teeth ( Figs 17B , 23B )...... 14

. Body more robust, about 3 × longer than wide. Anterior margin of pronotum without a row of teeth................... 16

14(13) Largest teeth on pronotum anterior margin located laterally; frons strongly gibbous forming a very pronounced transverse swelling ( Fig. 17A )................................................. Dolichobostrychus yunnannus Lesne, 1913

. Median two teeth on pronotum anterior margin more developed than lateral teeth; frons not transversely swollen, weakly convex............................................................................................... 15

15(14) Pronotum relatively short, rounded, its anterior margin not very strongly projecting over head ( Fig. 24A )................................................................................... .. Parabostrychus elongatus (Lesne, 1895)

. Pronotum more elongate, egg-shaped, its anterior margin strongly projecting over head ( Fig. 23A )......................................................................................... Parabostrychus acuticollis Lesne, 1913

16(13) Pronotum not impressed above middle of anterior margin.....................................................17

. Pronotum slightly impressed above middle of anterior margin ( Heterobostrychus Lesne )........................... 18

17(16) Medium sized species (6–21mm). Disc of pronotum with flattened, imbricate scale-like sculpture, lacking punctures ( Fig. 16 )....................................................................... Bostrychopis parallela Lesne, 1895

. Small species (3–6.5 mm). Disc of pronotum with strong, deep punctures, lacking imbricate scale-like sculpture ( Fig. 22 )....................................................................... Micrapate simplicipennis (Lesne, 1895)

18(16) Posterior angles of the prothorax rounded or very slightly projecting; disc of pronotum with flattened, imbricate scalelike sculp- ture, lacking punctures, at least posteriorly................................................................ 19

. Posterior angles of the prothorax strongly projecting and granulate; disc of pronotum coarsely, densely punctured, lacking imbricate scale-like sculpture...................................... Heteropbostrychus aequalis (Waterhouse, 1884)

19(18) Pronotum with imbricate scale-like sculpture only on posterior part of disc, distinctly punctured behind summit. Scutellar shield transverse, lunulate................................................... Heterobostrychus ambigenus Lesne, 1920

. Pronotum with imbricate scale-like sculpture extending from just behind summit to bases of pronotum. Scutellar shield square or rectangular....................................................................................... 20

20(19) Frons middle with a distinct prominence and dense fulvous hairs like a small conical horn elytra declivity without distinct hook-like tooth....................................................... Heterobostrychus unicornis Waterhouse,1879

. Frons middle without distinct prominence, elytra declivity with distinct hook-like tooth............................ 21

21(20) Elytra with short, appressed hairs ( Fig. 19 ). Usually larger, 11–15 mm long... Heterobostrychus hamatipennis (Lesne, 1895)

. Elytra glabrous ( Fig. 20 ). Always smaller, 9–11 mm long....................... Heterobostrychus pileatus Lesne, 1899

22(2) Antennae with eight segments.......................................................................... 23

. Antennae with more than eight segments.................................................................. 24

23(22) Antenna distinctly shorter than pronotum; funicle subequal in length to first antennomere of club; last antennomere with two distinct circular, sensory impressions ( Fig.32 )................................... Octodesmus parvulus (Lesne, 1897)

. Antenna distinctly longer than pronotum; funicle much shorter in length than first antennomere of club; last antennomere without sensory impressions.............................................. Octomeristes pusillus ( Liu & Beaver, 2016)

24(22) Prothorax with a very clear lateral carina, more or less prolonged, abruptly angled at the posterior angle, and briefly prolonged along the base...................................................................................... 25

. Prothorax without a lateral carina, or with a short slightly curved carina only on the posterior angles, not angular at the base. .................................................................................................. 29

25(24) Antennomeres of club elongate; frons with erect hairs; last visible segment of male abdomen with lateral pieces ( Fig. 43 )............................................................................ Xylothrips flavipes (Illiger, 1801)

. First and second segments of antennal club transverse; frons without erect hairs; last segment of male abdomen without lateral pieces ( Xylopsocus Lesne )............................................................................. 26

26(25) Antenna 10-segmented ( Fig. 39 ). Upper margin of elytral declivity with a pair of sharply pointed teeth on each side............................................................................ Xylopsocus acutespinosus Lesne, 1906

. Antenna 9-segmented. Upper margin of elytral declivity without sharply pointed teeth.............................. 27

27(26) Upper margin of elytral declivity bearing two pairs of blunt tubercles ( Fig. 41 )................................................................................... Xylopsocus intermedius (Damoiseau in Damoiseau et Coulon, 1993)

. Upper margin of elytral declivity without two pairs of blunt tubercles.......................................... 28

28(27) Declivital margin of elytra weakly bisinuate in upper third; elytral declivity quite strongly punctured, granulate-punctate only in upper third ( Fig. 40 ).................................................. Xylopsocus capucinus (Fabricius, 1781)

. Declivital margin of elytra with a sharp, inwardly-directed tooth in upper third; elytral declivity strongly granulate-punctate over whole surface ( Fig. 42 )..................................................... Xylopsocus radula Lesne, 1901

29(24) Without spines or tubercles present on margin of elytral declivity.............................................. 30

. At least one pair of spines or tubercles present on margin of elytral declivity..................................... 31

30(29) Elytral declivity oblique forming a shovel-like extension ( Fig. 34 )...................... Paraxylion bifer (Lesne, 1932)

. Elytral declivity steep, not shovel-like ( Fig. 35 ).................................... Xylocis tortilicornis Lesne, 1901

31(29) Antennae with very elongate club extending almost to abdominal apex. Posterior part of elytra close to declivity very coarsely punctured with rows of tubercular or spine-like processes on interstriae ( Fig. 31A, B )......... .. Calonistes vittatus sp. nov.

. Antennae less elongate, not extending to abdominal apex. Posterior part of elytra not as alternate.................... 32

32(31) First and second antennomeres of antennal club with two longitudinal bands of golden hairs on each side of each face ( Fig. 36A )..................................................................... Calophagus colombiana sp. nov.

. Antennal club without longitudinal bands of hairs, with or without small, distinct, subcircular sensory areas with denser pubescence.............................................................................................. 33

33(32) Body size smaller, not more than 6 mm long. Elytral declivity with two pairs of spines, the lower very long and curved medially...................................................................... Xylodectes ornatus (Lesne, 1897)

. Body size larger, exceeding 7 mm. Elytral declivity either with three distinct pairs of spines, or only blunt tubercles present. .................................................................................................. 34

34(33) Elytral declivity with three distinct pairs of spines on margin ( Figs 37 , 38 ) ( Xylodrypta Lesne, 1901 ).................. 35

. Elytral declivity with a pair of blunt tubercles at about mid-height of declivity ( Fig. 32B )............................................................................................. Gracilenta yingjiangensis gen. nov., sp. nov.

35(34) Declivital spines sharply pointed, acuminate, distinctly separated from each other ( Fig. 38B, E ). Female abdomen without spiny processes on fourth ventrite ( Fig. 38C )............................................. Xylodrypta zhenghei sp. nov.

- Declivital spines less sharply pointed, the bases broadened and not distinctly separated ( Fig. 37A, B ). Female abdomen with long, spiny processes on fourth ventrite ( Fig. 37C ).................................. Xylodrypta guochanii sp. nov.

Figures

FIGURE 3. Intercoxal process of first abdominal ventrite of Bostrichini (A) and Xyloperthini (B).

FIGURE 16. (A, B, C, D) Lateral (A♂, C♀) and dorsal (B♂, D♀) views of Bostrychopsis parallela (Lesne, 1895). Total horizontal scale bar of both B and D =1 mm.

FIGURE 17. (A, B) Lateral (A) and dorsal (B) views of Dolichobostrychus yunnannus Lesne, 1913. Total horizontal scale bar of B =1 mm.

FIGURE 19. (A, B) Lateral (A) and dorsal (B) views of Heterobostrychus hamatipennis (Lesne, 1895) (♂). Total horizontal scale bar of B =1 mm.

FIGURE 20. (A, B, C, D) Lateral (A♂&C♀) and dorsal (B♂&D♀) views of Heterobostrychus pileatus Lesne, 1899. Total horizontal scale bar of B and D =1 mm.

FIGURE 21. (A, B) Lateral (A) and dorsal (B) views of Lichenophanes carinipennis (Lewis, 1896). Total horizontal scale bar of B =1 mm.

FIGURE 22. (A, B) Lateral (A) and dorsal (B) views of Micrapata simplicipennis (Lesne, 1895). Total horizontal scale bar of B =1 mm.

FIGURE 23. (A, B) Lateral (A) and dorsal (B) views of Parabostrychus acuticollis Lesne, 1913. Total horizontal scale bar of B =1 mm.

FIGURE 24. (A, B) Lateral (A) and dorsal (B) views of Parabostrychus elongatus (Lesne, 1895). Total horizontal scale bar of B =1 mm.

FIGURE 25. (A, B) Lateral (A) and dorsal (B) views of Sinoxylon anale Lesne, 1897. Total horizontal scale bar of B =1 mm.

FIGURE 26. (A, B) Lateral (A) and dorsal (B) views of Sinoxylon crassum Lesne, 1897. Total horizontal scale bar of B =1 mm.

FIGURE 27. (A, B) Lateral (A) and dorsal (B) views of Sinoxylon flabrarius Lesne, 1906. Total horizontal scale bar of B =1 mm.

FIGURE 28. (A, B) Lateral (A) and dorsal (B) views of Sinoxylon fuscovestitum Lesne, 1919. Total horizontal scale bar of B =1 mm.

FIGURE 29. (A, B) Lateral (A) and dorsal (B) views of Sinoxylon pygmaeum Lesne, 1897. Total horizontal scale bar of B =1 mm.

FIGURE 30. (A, B, C) Lateral (A), dorsal (B) and posterior 45° angel views of Sinoxylon tignarium Lesne, 1902. Total horizontal scale bar of B =1 mm.

FIGURE 31. (A, B, C, D, E) Lateral (A), dorsal (B), (C) antenna sensory depression, (D) posterior abdomen segment (♂) and (E) (♀) views of Calonistes vittatus sp. nov. Total horizontal scale bar of B =1 mm.

FIGURE 32. (A, B, C, D, E) Lateral (A), dorsal (B), (C) abdomen(♂), (D) head and (E) posterior 45° angel views of Gracilenta yingjiangensis gen. et sp. nov.. Total horizontal scale bar of B =1 mm.

FIGURE 34. Lateral (A), dorsal (B) and (C) antennae views of Paraxylion bifer (Lesne, 1932), Total horizontal scale bar of B =1 mm.1 micro vertical scale bar of C = 0.01 mm, and total vertical scale bar of C = 1mm.

FIGURE 35. (A, B, C, D) Lateral (A♀&C♂) and dorsal (B♀&D♂) views of Xylocis tortilicornis Lesne, 1901. Total horizontal scale bar of B and D=1 mm.

FIGURE 36. (A, B, C, D, E) Lateral (A), dorsal (B), abdomen (C♀, D♂) and longitudinal bands on club antennomeres views of Calophagus colombiana sp.nov.. Total horizontal scale bar of B =1 mm.

FIGURE 37. (A, B, C, D, E) Lateral (A), dorsal (B), abdomen (C♀, D♂) and posterior 45° angel views of Xylodrypta guochuanii sp.nov.. Total horizontal scale bar of B =1 mm.

FIGURE 38. (A, B, C, D, E, F, G) Lateral (A), dorsal (B), abdomen segment (C♂, D♀), genitalia (E♂, F♀) and posterior decliv- ity (G) of Xylodrypta zhenghei sp.nov., 1 micro scale bar of E and F = 0.01 mm, and total scale bar of E and F= 1mm.

FIGURE 39. (A, B, C, D, E, F) Front and anterior 45° angel views on head of Calophagus colombiana sp.nov. (A, D), Xylodrypta guochuanii sp.nov. (B, E) and Xylodrypta zhenghei sp.nov. (C, F).

FIGURE 40. (A, B) Lateral (A) and dorsal (B) views of Xylopsocus acutespinosus Lesne, 1906. Total horizontal scale bar of B =1 mm.

FIGURE 41. (A, B) Lateral (A) and dorsal (B) views of Xylopsocus capucinus (Fabricius, 1781). Total horizontal scale bar of B =1 mm.

FIGURE 42. (A, B) Lateral (A) and dorsal (B) views of Xylopsocus intermedius Damoiseau in Damoiseau et Coulon, 1993. Total horizontal scale bar of B =1 mm.

FIGURE 43. (A, B) Lateral (A) and dorsal (B) views of Xylopsocus radula Lesne, 1901. Total horizontal scale bar of B =1 mm.