Tychius gracilitubus ( Bajtenov, 1977 )

Jiang, Chunyan, Caldara, Roberto & Zhang, Runzhi, 2020, The genus Tychius Germar (Coleoptera: Curculionidae: Curculioninae) in China, with description of three new species, Zootaxa 4856 (1), pp. 1-62 : 36-37

publication ID	https://doi.org/ 10.11646/zootaxa.4856.1.1
publication LSID	lsid:zoobank.org:pub:0C2E90FC-25FD-455D-86A7-0BA8210C0A30
DOI	https://doi.org/10.5281/zenodo.4411367
persistent identifier	https://treatment.plazi.org/id/632E87E8-FF9C-FFD5-E6D5-FB7EFA9683BF
treatment provided by	Plazi
scientific name	Tychius gracilitubus ( Bajtenov, 1977 )
status

Treatment

33. Tychius gracilitubus ( Bajtenov, 1977) View in CoL

( Figures 109–112 View FIGURES 109–120 , 231–234 View FIGURES 221–242 , 301–302 View FIGURES 275–306 , 337 View FIGURES 307–339 , 349, 361 View FIGURES 340–363 , 394 View FIGURES 388–396 , 429 View FIGURES 397–431 , 455 View FIGURES 432–457 , 482 View FIGURES 458–484 )

Lepidotychius gracilitubus Bajtenov, 1977: 162 View in CoL . Caldara, 1986: 187 ( Tychius View in CoL ).

Material examined. CHINA: Shaanxi: Yulin Dingbian (1400 m), 1-VI-1987 (2); same data, 29-VII-1987 (3); Yulin Dingbian (1300 m), 30-VII-1986 (1); Jingbian, Jinjisha reservoir (37°37’N; 108°28’E, 1346m), Hedysarum fruticosum var. mongolicum , leg Chunyan Jiang, Xiaoliang Yang (3); Chengchuan (37°53’N; 108°1’E, 1360 m), Hedysarum fruticosum var. mongolicum , 21-V-2019, leg Chunyan Jiang, Xiaoliang Yang (4).

Redescription. Length 1.90–2.20 mm ( Fig. 109–112 View FIGURES 109–120 ). Dorsal integument completely hidden by very dense, overlapped, broad, rounded to oval, yellowish scales, irregularly arranged on elytral interstriae. Rostrum ( Fig. 231– 234 View FIGURES 221–242 ) in lateral view strongly curved in both sexes, especially in female (Rl/Rw 5.20–5.30 in male, 7.50–7.60 in female; Rl/Pl 0.80–0.91 in male, 1.10–1.27 in female). Eyes flat. Pronotum (Pw/Pl 1.10–1.22) with subrectilinear sides in basal half. Elytra rectangular (Ew/Pw 1.25–1.37; El/Ew 1.50–1.61), elongate. Femora ( Fig. 301–302 View FIGURES 275–306 ) unarmed, tibiae ( Fig. 337 View FIGURES 307–339 ) without sexual characters. Third tarsomere moderately wider than second tarsomere ( Fig. 349 View FIGURES 340–363 ). Claws ( Fig. 361 View FIGURES 340–363 ) with small medial teeth, a little less long than half of claw, fastened to claw in basal half. Male genitalia: body of penis ( Fig. 394 View FIGURES 388–396 ) moderately wide and with sides slightly convergent in basal 1/3, then distinctly narrowed and parallel sided to apex, with subacute tip in dorsal view ( Fig. 429 View FIGURES 397–431 ), with apex in lateral view upturned, twice longer than apodeme. Female genitalia: spermatheca ( Fig. 455 View FIGURES 432–457 ) with long parallel-sided ramus, at right angle to cornu, short thin collum placed not at same plane of cornu as usually but at 90°, robust nodulus, cornu gradually narrowing to apex; spiculum ventrale ( Fig. 482 View FIGURES 458–484 ) with arms slightly spaced and convergent in basal half, then joined to apex.

Remarks and comparative notes. This species is closely related to T. hedysaricus , from which it differs by the more curved rostrum in lateral view (especially in the female) and the more narrowed apical part of the penis in dorsal view. These same characters allow us to distinguish this species from all the others of the group. In three specimens of T. gracilitubus we did not find the apodemes of the penis ( Fig. 393 View FIGURES 388–396 ) (see Discussion).

Biology. Recently some specimens were collected on Hedysarum fruticosum var. mongolicum . We also examined one specimen labeled as collected on Nitraria tangutorum Bobr. (Nitrariaceae) ; however, we believe this association to be incidental.

Distribution. This species was previously known only from Mongolia. New record from China (SHA).