35. Tychius crassifemoris (Bajtenov, 1977)

(Figures 117–120, 123–124, 239–242, 305–306, 339, 351, 363, 396, 431, 457, 484)

Lepidotychius crassifemoris Bajtenov, 1977: 161 . Caldara, 1986: 188 ( Tychius).

Material examined. CHINA: Shaanxi: Yulin, Jingbian, Sidaohaize (37°40’N; 108°50’E, 1331 m), Hedysarum fruticosum var. mongolicum, 22-V-2019, leg Chunyan Jiang, Xiaoliang Yang (11); Jingbian, Niuyuqin desertification control farm (37°38’N; E108°32’, 1347 m), Hedysarum fruticosum var. mongolicum, 21-V-2019, leg Chunyan Jiang, Xiaoliang Yang (10); Jinjisha reservoir (37°37’N; 108°28’E, 1346 m), Medicago sativa, leg Chunyan Jiang, Xiaoliang Yang (20); Dingbian, Xukengcun (37°30’N; 107°52’E, 1412 m), Medicago sativa, leg Chunyan Jiang, Xiaoliang Yang (27); Hedysarum fruticosum var. mongolicum, 29-VII-1987 (1). Inner Mongolia: Otog Qianqi, Aozhen (38°9’N; 107°30’E; 1337 m), Hedysarum fruticosum var. mongolicum, 19-V-2019, leg Chunyan Jiang, Xiaoliang Yang (12); Dashatou (38°9’ N; 107°34’E, 1345 m), Hedysarum fruticosum var. mongolicum, 22-V-2019, leg Chunyan Jiang, Xiaoliang Yang (19); Chengchuan (37°53’N; 108°1’E, 1360 m), Hedysarum fruticosum var. mongolicum, 21-V-2019, leg Chunyan Jiang, Xiaoliang Yang (34).

Redescription. Length 1.95–2.45 mm (Fig. 117–120). Dorsal integument completely hidden by very dense, distinctly overlapped, broad, rounded to oval, yellowish scales, irregularly arranged on elytral interstriae; striae visible, with a row of thin scales. Rostrum (Rl/Rw 3.91–4.27 in male, 4.09–5.00 in female; Rl/Pl 0.61–0.70 in male, 0.71–0.78 in female) (Fig. 239–242) in lateral view slightly curved in both sexes, poorly sexually dimorphic. Eyes slightly convex. Pronotum slightly longer than wide (Pw/Pl 1.04–1.10), with subrectilinear sides in basal half. Elytra (Ew/Pw 1.10–1.35; El/Ew 1.50–1.75) rectangular, elongate and with subrectilinear sides in basal 2/3. Abdomen in female: ventrite 5 with a deep median fovea and with apical part bisinuous and protruding at middle (Fig. 124); pygidium with two lateral protuberances at its apex. Femora (Fig. 305–306) unarmed, tibiae (Fig. 339) without sexual characters. Third tarsomere distinctly wider than second tarsomere (Fig. 351). Claws (Fig. 363) with small medial teeth, as long as 1/3 of claw, fastened to claw in basal half. Male genitalia: body of penis (Fig. 396) with sides distinctly narrowing in basal quarter then parallel-sided until near apex, with subacute tip (Fig. 431) in dorsal view, with apex in lateral view slightly upturned, as long as apodeme. Female genitalia: spermatheca (Fig. 457) with long parallel-sided ramus, short robust collum, moderately robust nodulus, cornu gradually narrowing to apex; spiculum ventrale (Fig. 484) with arms slightly spaced and convergent in basal half, then joined to apex.

Remarks and comparative notes. Apart from the short and weakly sexually dimorphic rostrum, this species is distinctly different from all others by two unique characters in the female: pygidium with two lateral protuberances and ventrite 5 with a median deep fovea and the posterior margin sinuous and prominent in the middle (see fig. 123 vs fig. 124).

Biology. Recently this species was collected on Hedysarum fruticosum Pall. var. mongolicum (Turcz) B. Fedtsch and Medicago sativa L.; we believe the latter association to be incidental.

Distribution. This species was previously known from Russia (Siberia) and Mongolia. New record from China (NMO SHA).

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Key to species of Chinese Tychius

1. Segments of antennal funicle, femora and tibiae almost completely hidden by recumbent to subrecumbent, subelliptical to subrounded scales (Fig. 215–218, 283–306, 327–339, 340–351). Spermatheca with base of ductus sclerotized (Fig. 448–457) ................................................................................................... 2

- Segments of antennal funicle, femora and tibiae visible between subrecumbent to suberect seta-like scales or less elongate scales (Fig. 125–128, 243–282, 307–326). Spermatheca with ductus not sclerotized (Fig. 432–447)................... 13

2. Pronotum completely concealed by partly imbricate, recumbent, wide, subrounded scales with recumbent, seta-like scales intermixed (Fig. 73–100). Male pygidium with transverse ridge (Fig. 121)........................................ 3

- Vestiture of pronotum otherwise (Fig. 101–120). Male pygidium without transverse ridge (Fig. 122)................... 9

3. Upper margin of rostrum in lateral view distinctly curved in basal third (Fig. 212–222).............................. 4

- Upper margin of rostrum in lateral view almost straight in basal third (Fig. 198–210)................................ 6

4. Tooth at base of claw 2/3 as long as claw (Fig. 356–357). Rostra as in Fig. 211–218................................ 5

- Tooth at base of claw 1/3 as long as claw (Fig. 358). Rostra as in Fig. 219–222........................... 30 T . zhangi

5. Rostrum longer (Rl/Pl 0.85–0.93 in male, 0.90–0.97 in female), in lateral view distinctly tapered and slender from antennal insertion to apex especially in female (Fig. 212, 214); colour of vestiture on dorsum usually sulphur-yellow, more rarely grayish yellow (Fig. 89–92)....................................................................... 28 T. sulphureus

- Rostrum shorter (Rl/Pl 0.83–0.84 in male, 0.82–0.85 in female), stout, in lateral view weakly tapered from antennal insertion to apex (Fig. 216, 218); colour of vestiture on dorsum grayish (Fig. 93–96).............................. 29 T. obrieni

6. Pronotum slightly curved at sides, distinctly narrower than elytra (Fig. 73, 75, 85, 88). Rostrum in lateral view slightly curved in apical 2/3, weakly sexually dimorphic (Fig. 195–198, 207–210).............................................. 7

- Pronotum distinctly curved at sides, slightly narrower than elytra (Fig. 77, 79, 81, 83). Rostrum in lateral view curved at antennal insertion, distinctly sexually dimorphic (Fig. 199–206)................................................ 8

7. Tooth at base of claw 1/3 as long as claw (Fig. 352). Third tarsomere distinctly wider than second tarsomere (Fig. 340)............................................................................................ 24 T. morawitzi

- Tooth at base of claw 2/3 as long as claw (Fig. 355). Third tarsomere only moderately wider than second tarsomere (Fig. 343)...................................................................................... 27 T. tachengicus

8. Rostrum in dorsal view subparallel-sided or feebly enlarged in apical fourth, in lateral view distinctly narrowed at apex (Fig. 203–206).................................................................................. 26 T. urbanus

- Rostrum in dorsal view narrowed in apical fourth, in lateral view subparallel-sided from antennal insertion to apex (Fig. 199–202).................................................................................. 25 T. winkleri

9. Pronotum covered with flat, rectangular to subelliptical scales (Fig. 105–108). Tooth at base of claw robust, as long as 2/3 length of claw (Fig. 360)......................................................................32 T. kaszabi

- Pronotum covered with partly concave, round scales (Fig. 101–102, 109–120). Tooth at base of claw small, at most as long as 1/2 length of claw (Fig. 359, 361–363)................................................................... 10

10. Rostrum in lateral view strongly curved in both sexes, especially in female (Fig.232, 234)............... 33 T. gracilitubus

- Rostrum in lateral view weakly curved................................................................... 11

11. Rostrum short (Rl/Pl 0.61–0.78), weakly sexually dimorphic (Fig. 239–242). Female with pygidium with two lateral protuberances and ventrite 5 with a median deep fovea and posterior margin sinuous and prominent at middle (Fig. 124)........................................................................................ 35. T. crassifemoris

- Rostrum longer (Rl/Pl 0.77–1.03), distinctly sexually dimorphic (Fig. 223–224, 235–238). Female with pygidium and ventrite 5 without particular characters (Fig. 123)................................................................. 12

12. Rostrum nearly straight (Fig. 224) especially in female. Protibiae in male distinctly arcuate (Fig. 334).......31. T. bajtenovi

- Rostrum more curved (Fig. 236–238) especially in female. Protibiae in male weakly arcuate (Fig. 338)..........................................................................................................34. hedysaricus

13. Scales on elytral interstriae 2–10 of two different forms, narrow and wide more or less intermixed (e.g. Fig. 13, 17, 25, 29).. .................................................................................................. 14

- Scales on elytral interstriae 2–10 uniform, from narrow to wide (e.g. Fig. 37, 39, 51, 67)............................ 22

14. Elytral interstriae completely concealed by dense, imbricate, broad, oval to elliptical or lanceolate scales, unevenly arranged, with sparse narrow lanceolate scales feebly raised in part. Body length mm> 4.00 mm.................. 3 T. herculeanus

- Elytral vestiture otherwise. Body length usually <4.00 mm................................................... 15

15. Elytra subrectangular, with subparallel sides....................................................... 5 T. longulus

- Elytra subglobose, oval to suboval-oblong, with more or less rounded sides (e.g. Fig. 17–32)........................ 16

16 Funicle with six segments. Scales on interstriae and pronotum wide, oval (Fig. 11–14)............... 6. T. praescutellaris

- Funicle with seven segments. Scales on dorsal vestiture sometimes narrow at least in part........................... 17

17. Broad scales on elytral interstriae numerous and uniformly arranged throughout. Scales of middle row narrow, about 1/3–1/2 width of those on other rows on interstriae (Fig. 29–32)............................................... 12 T. ovalis

- Broad scales on elytral interstriae very sparse or at least covering only a portion of interstriae (e.g. Fig. 17–28).......... 18

18. Third tarsomere only slightly wider than second................................................ 10 T. thompsoni

- Third tarsomere distinctly wider than second.............................................................. 19

19. Integument partly exposed between narrow hair-like scales (Fig. 25–28)................................ 11 T. perrinae

- Integument almost completely hidden by wider rectangular scales (Fig. 7–10, 17–24).............................. 20

20. Narrow scales on dorsum, femora and tibiae white and red (Fig. 7–10)................................. 4 T. uralensis

- Narrow scales on dorsum and legs unicolorous to feebly bicoloured (Fig. 17–24).................................. 21

21. Eyes flat. Rostrum generally shorter especially in female (Rl/Pl 0.90–1.00 in male, 0.94–1.06 in female) (Fig. 145–148)................................................................................................9 T. oriens

- Eyes slightly prominent. Rostrum generally longer especially in female (Rl/Pl 0.90–1.15 in male, 1.08–1.25 in female) (Fig. 141–144)..................................................................................... 8 T. tectus

22. Body length> 2.90mm ................................................................................ 23

- Body length <2.60mm ................................................................................ 25

23. Eyes strongly prominent (Fig. 125–128). Pronotum and elytra with distinctly rounded sides (Fig. 1–4). Profemur of male with a fringe of long hairs (Fig. 243).............................................................. 1 T. albolineatus

- Eyes slightly prominent to flat. Pronotum and elytra with slightly to moderately rounded sides. Profemur of male without fringe of long hairs........................................................................................ 24

24. Pronotum with moderately rounded sides, not subconical (Fig. 15–16). Eyes moderately prominent (Fig. 139–140). Protibia without tooth in male (Fig. 311)..................................................................7 T. hauseri

- Pronotum with nearly rectilinear sides, subconical (Fig. 5–6). Eyes flat (Fig. 129–130). Protibia with tooth in male..................................................................................................2 T. rufirostris

25. Eyes completely flat (Fig. 179–182, 187–190)............................................................. 26

- Eyes more or less prominent........................................................................... 27

26. Rostrum in lateral view regularly curved at base and gradually tapered in apical part (Fig. 188, 190). Sides of pronotum curved (Fig. 63–66). Scales on elytra wide. Protibia without tooth on inner margin in male (Fig. 325)............22 T. breviusculus

- Rostrum in lateral view strongly curved at base and markedly tapered in apical part (Fig. 180, 182). Sides of pronotum subparallel in basal half (Fig. 55–58). Protibia with tooth on inner margin in male (Fig. 322–323).............19 T. meliloti

27. Scales of elytral interstriae oval to subelliptical, often elongate but never hair-like, concealing integument.............. 28

- Scales of elytral interstriae narrow, usually hair-like leaving integument a little visible.............................. 33

28 Rostrum short and stout (Rl/Pl 0.73–0.83 in male, 0.77–0.87 in female) (Fig. 175–178)................. 18 T. crassirostris

- Rostrum longer and thinner (e.g. Fig. 157–174)............................................................ 29

29 Scales on striae wide, nearly of same width as those on interstriae (Fig. 35–38)............................ 14 T. flavus

- Scales on striae hair-like, usually thinner than those on interstriae (Fig. 33–34, 39–50).............................. 30

30. Elytra with scales of interstriae broad, distinctly wider than scales covering striae (Fig. 33–34)...........13 T. squamulatus

- Elytra with scales of interstriae elongate, slightly wider than scales covering striae (Fig. 39–50)...................... 31

31. Rostrum in lateral view distinctly flattened in apical portion (Fig. 164, 166, 172, 174).............................. 32

- Rostrum in lateral view cylindrical or gradually flattened in apical portion (Fig. 168, 170)............... 16 T. medicaginis

32. Elytra oblong-oval (Fig. 39–42). Profemora in male with fringe of scales (Fig. 265)....................... 15 T. aureolus

- Elytra short-oval (Fig. 47–50), heart-shaped. Profemora in male without fringe of scales (Fig. 269)..........17 T. junceus

33 Funicle with six segments.................................................................. 23 T. picirostris

- Funicle with seven segments........................................................................... 34

34. Rostrum in lateral view gradually tapered in apical portion (Fig. 184, 186). Vestiture on elytral interstriae denser (Fig. 59–62)............................................................................................20 T. vossi

- Rostrum in lateral view distinctly flattened in apical portion. Vestiture on elytral interstriae sparse..........21 T. kerulensis