Ichthyurus longulus Y. Yang, Lin & Liu, 2024

Lin, Hanqing, Liu, Haoyu, Yang, Xingke & Yang, Yuxia, 2024, A new and widely distributed species of Ichthyurus Westwood, 1848 (Cantharidae, Chauliognathinae, Ichthyurini) from China, Biodiversity Data Journal 12, pp. e 131829-e 131829 : e131829-

publication ID	https://doi.org/ 10.3897/BDJ.12.e131829
publication LSID	lsid:zoobank.org:pub:8F69E1B3-5326-41A9-B19C-826883D5EEAB
DOI	https://doi.org/10.5281/zenodo.13802121
persistent identifier	https://treatment.plazi.org/id/133C3ECD-A23A-5F86-AB57-DC5B1948B466
treatment provided by	Biodiversity Data Journal by Pensoft
scientific name	Ichthyurus longulus Y. Yang, Lin & Liu
status	sp. nov.

Treatment

Ichthyurus longulus Y. Yang, Lin & Liu sp. nov.

Materials

Type status: Holotype. Occurrence: recordedBy: Hanqing Lin; sex: 1 male; occurrenceID: 68041DAD-2F34-50A7-8275-90B683A81B1C; Location: country: China; county: Chongqing; municipality: Jinfoshan, Sanquan, Qishutang; verbatimElevation: 1288 m; verbatimLatitude: 29.05684 ° N; verbatimLongitude: 107.16292 ° E; Event: year: 2024; month: 5; day: 14; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Hanqing Lin; sex: 3 males, 3 females; occurrenceID: EEE9D361-7CB3-5222-8F85-210B28DA1388; Location: country: China; county: Chongqing; municipality: Jinfoshan, Sanquan, Qishutang; verbatimElevation: 1288 m; verbatimLatitude: 29.05684 ° N; verbatimLongitude: 107.16292 ° E; Event: year: 2024; month: 5; day: 14; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Jialing Chen; sex: 1 male, 1 female; occurrenceID: 5897DA38-C9B0-5630-8F0A-39C0903CCC2A; Location: country: China; county: Chongqing; municipality: Jinfoshan, Sanquan, Nanmuwan; verbatimElevation: 1304 m; verbatimLatitude: 29.05471 ° N; verbatimLongitude: 107.17426 ° E; Event: year: 2024; month: 5; day: 13; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Liang Zhang; sex: 1 male; occurrenceID: 29ADF61A-4BBD-5280-83CB-494132E08CEE; Location: country: China; county: Chongqing; municipality: Toudu, Dianchanggou; verbatimElevation: 902 m; verbatimLatitude: 29.01685 ° N; verbatimLongitude: 107.08325 ° E; Event: year: 2024; month: 5; day: 8; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Ping Wang; sex: 1 male; occurrenceID: 22CEEED2-BAAE-54C3-9CF1-035B3652E8D1; Location: country: China; county: Chongqing; municipality: Jinfoshan, Sanquan; verbatimElevation: 1303 m; verbatimLatitude: 29.05460 ° N; verbatimLongitude: 107.17426 ° E; Event: year: 2024; month: 5; day: 30; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Wangang Liu; sex: 1 male; occurrenceID: 2AB46BC0-2331-52F0-82BD-01D462B1D75C; Location: country: China; county: Chongqing; municipality: Jinfoshan; verbatimElevation: 1601 m; verbatimLatitude: 29.08333 ° N; verbatimLongitude: 107.18333 ° E; Event: year: 2010; month: 6; day: 13; Record Level: institutionID: Institute of Zoology, Chinese Academy of Sciences; institutionCode: IZAS GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Caixia Yuan and Yushuang Liu; sex: 1 female; occurrenceID: B90C235A-94CA-58A8-B631-8EE288F1B222; Location: country: China; stateProvince: Shannxi; municipality: Ziyang, Maoba; verbatimElevation: 1303 m; verbatimLatitude: 29.05460 ° N; verbatimLongitude: 107.17426 ° E; Event: year: 2003; month: 7; day: 8; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Xingke Yang; sex: 1 female; occurrenceID: F518E424-6255-587C-8AAA-F5210046DAB0; Location: country: China; stateProvince: Gansu; municipality: Wenxian, Bikou, Bifenggou; verbatimElevation: 900‒1450 m; Event: year: 1998; month: 6; day: 25; Record Level: institutionID: Institute of Zoology, Chinese Academy of Sciences; institutionCode: IZAS

Type status: Paratype. Occurrence: recordedBy: Tengfei Qiu; sex: 1 male; occurrenceID: 460A0351-0598-5D67-9DA4-40FC28750D7F; Location: country: China; stateProvince: Hubei; county: Yichang; municipality: Dalaoling; Event: year: 2015; month: 5; day: 6; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU

Type status: Paratype. Occurrence: recordedBy: Xiujuan Yang; sex: 1 female; occurrenceID: 10FF9330-9638-5D0A-A343-8473E1E8F7BB; Location: country: China; stateProvince: Guangxi; county: Baise; municipality: Tianlin, Yaojiawan; verbatimElevation: 1200‒1400 m; Event: year: 2002; month: 4; day: 1; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU

Type status: Paratype. Occurrence: recordedBy: Yang Yu; sex: 1 female; occurrenceID: C7A17B9C-FB3F-5CFF-98C5-06E41AE91381; Location: country: China; stateProvince: Guizhou; county: Daozhen; municipality: Yangxi, Qishiyan; Event: year: 2004; month: 4; day: 29; Record Level: institutionID: Museum of Hebei University; institutionCode: MHBU

Type status: Paratype. Occurrence: recordedBy: Jiang, Jiang, Hu, Liu, & Zhang; sex: 1 female; occurrenceID: ADAA029C-424E-5ED0-9722-AE9C9B96FB76; Location: country: China; stateProvince: Guizhou; county: Libo; municipality: Maolan N. R., Bizuo; verbatimElevation: 587 m; verbatimLatitude: 25.28306 ° N; verbatimLongitude: 108.05500 ° E; Event: year: 2017; month: 4; day: 28; Record Level: institutionID: Insect Collection of Shanghai Normal University; institutionCode: SNUC GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Jiang, Jiang, Hu, Liu, & Zhang; sex: 1 female; occurrenceID: 3719E996-959A-592A-82DE-DC6BBE61FF78; Location: country: China; stateProvince: Guizhou; county: Libo; municipality: Maolan N. R., Dongdai; verbatimElevation: 865 m; verbatimLatitude: 25.31417 ° N; verbatimLongitude: 107.95056 ° E; Event: year: 2017; month: 4; day: 23; Record Level: institutionID: Insect Collection of Shanghai Normal University; institutionCode: SNUC GoogleMaps

Type status: Paratype. Occurrence: recordedBy: Tianjun Liu; sex: 1 female; occurrenceID: 6764D079-A8F2-5FA2-8DEE-B9509B8F9858; Location: country: China; stateProvince: Guizhou; municipality: Jiangkou, Kuaichang; Event: year: 2021; month: 5; day: 28; Record Level: institutionID: Institute of Entomology, Guizhou University; institutionCode: GUGC

Type status: Paratype. Occurrence: recordedBy: Tianjun Liu; sex: 1 female; occurrenceID: 3B3E03D5-DDFD-5B4D-9897-E5A7DC229F8B; Location: country: China; stateProvince: Guizhou; municipality: anjingshan, Jiangkou, Kuaichang, Mingjingshan; Event: year: 2021; month: 5; day: 26; Record Level: institutionID: Institute of Entomology, Guizhou University; institutionCode: GUGC

Description

Body length (both sexes): 13.5‒14.4 mm (13.5 mm in holotype); width at humeri (both sexes): 1.9‒2.0 mm (1.9 mm in holotype).

Male (Fig. 1 View Figure 1 A). Colouration. Body black, antennomere I yellow ventrally; prothorax yellow, pronotum with a small black marking at middle of anterior margin; metaventrite each side with a longitudinal yellow marking; metanepisternum and scutellum yellow; abdominal segments II ‒ VII narrowly yellow at lateral and posterior margins.

Eyes large, interocular distance about half of maximum eye diameter. Antennae reaching posterior margin of abdominal tergite III, antennomeres II about 1 / 3 of the length of I, III ‒ XI subequal in length and about 4.0 times longer than II.

Pronotum 1.1 times wider than long, anterior margin strongly arcuate and lateral margins slightly arcuate, posterior margin feebly bisinuate, anterior angles rounded and posterior angles nearly rectangular.

Leg slender, mesotibiae each present with a spur at inner apical angle (Fig. 1 View Figure 1 a).

Elytra 1.3 times longer than humeri width of conjoint elytra, twice longer than pronotum, with lateral margins sinuate, sutures moderately dehiscent at posterior 2 / 3 part, distance between sutures twice wider than width of an elytron, apices rounded.

Terminal abdominal tergite (or tergite VIII) (Fig. 2 View Figure 2 A and B) with lateral projections long and cylindrical, about 3 / 5 of the length of the tergite. Terminal abdominal ventrite (or sternite VIII) (Fig. 2 View Figure 2 D) widened apically, saddle-shaped and deeply cleft in middle of apical 2 / 3 part, with lateral margins feebly arcuate, inner apical angles largely and rectangularly emarginate, outer apical angles feebly widened and truncate at apices.

Abdominal sternite IX completely concealed underneath terminal ventrite (Fig. 2 View Figure 2 A), axe-like (Fig. 2 View Figure 2 G), with posterior right angle triangularly projecting posteriorly, posterior left angle rectangular, anterior right angle strongly and narrowly protruding anteriorly, rod-like and rounded at apex.

Proctiger (Fig. 2 View Figure 2 F) completely surrounded by paraproct, strongly sclerotised on both sides and almost membranous in middle, with lateral margins converging posteriorly. Paraproct (Fig. 2 View Figure 2 F) well-developed and tubular, feebly shrunk apically, shallowly emarginate in middle of dorso-posterior margin, present with a median longitudinal ridge on ventral side, surface coarsely punctate and covered with long and stout setae, tergal flange weakly sclerotised, strongly expanded at base and narrowly protruding apically.

Aedeagus (Fig. 4 View Figure 4 A ‒ D): left and right parameres both slender and nearly straight, subequal in length (Fig. 4 View Figure 4 A, D), rounded at apex; right paramere covered with a few short setae at outer side (Fig. 4 View Figure 4 B); setifore extension strongly sclerotised, nearly as long as parameres, with a cluster of long setae at apex (Fig. 4 View Figure 4 B and C); median lobe medium-length, about twice longer than parameres, apex rounded.

Female (Fig. 1 View Figure 1 B). Similar to males, but mesotibial spur absent (Fig. 1 View Figure 1 b), terminal abdominal tergite with lateral projections feebly stouter and horn-shaped, progressively thinned apically (Fig. 2 View Figure 2 C); terminal abdominal ventrite (Fig. 2 View Figure 2 E) parallel-sided and arcuately narrowed at posterior 1 / 3 part, present with a pair of small protuberances in middle of posterior margin.

Reproductive system (Fig. 4 View Figure 4 E ‒ F): coxites long and fused medially, styles thin and short; vagina elongate, with median oviduct situated in middle of ventral side; bursa copulatrix arising from apex of vagina, swollen and suddenly thinned apically; accessory gland opening at dorsal base of bursa copulatrix, long and slightly expanded at apical 3 / 4 part; a spermatheca in the form of two short canals and arising from ventro-basal part of bursa copulatrix.

Variation within type series. Sometimes pronotum with a large black marking at anterior half part of the disc (Fig. 1 View Figure 1 C) or almost black with narrow yellow lateral margins (Fig. 1 View Figure 1 D). Their aedeagi (Fig. 3 View Figure 3 ) same to the holotype.

Diagnosis

It can be easily distinguished from all Chinese species by the uniformly black elytra (Fig. 1 View Figure 1 ), as opposed to the bicoloured and mixed with black and yellow in others. Meanwhile, each mesotibia is present with an apical spur in male (Fig. 1 View Figure 1 a), while absent in the other species or, at most, each protibia with an apical spine in I. vandepolli Gestro, 1892 . Additionally, its terminal abdominal tergite is characterised by long lateral projections, approximately 3 / 5 of the length of the tergite (Fig. 2 View Figure 2 A ‒ B), whereas in other species, it is, at most, half as long. Furthermore, its aedeagus bears a long setifore extension nearly equal in length to the parameres (Fig. 4 View Figure 4 A and D), unlike other species where it is much shorter than the parameres. Moreover, it can be readily differentiated from I. davidi Gestro, 1892 and I. vandepolli by its slender legs in male (Fig. 1 View Figure 1 A, C and D) (while meso- or profemora are at least moderately expanded in the latter species) and from I. bourgeoisi 1892 and I. savioi Pic, 1928 by its terminal abdominal tergite with simple lateral projections in male (Fig. 2 View Figure 2 A ‒ B) (as opposed to being excavated ventrally in the latter species).