Zaitzevia sichuanensis Jiang & Chen, 2023

Jiang, Ri-Xin & Chen, Xiang-Sheng, 2023, Three new species of the genus Zaitzevia Champion, 1923 (Coleoptera, Elmidae) from China, ZooKeys 1174, pp. 191-206 : 191

Zaitzevia sichuanensis Jiang & Chen sp. nov.

Figs 1A , 2 , 3 , 9A-D 川寥溪泥甲

Type material

(2 ♂♂, 2 ♀♀). Holotype: China: ♂, labeled 'China: Sichuan, Ya’an City (雅安市), Muping Town (穆坪镇), Lengmugou Geopark (冷木沟地质公园), an unnamed stream, 30°22′25′′N, 102°48′52′′E; H: 935m, 25.07.2022, R.-X. Jiang & F.-E. Li leg.' (GUGC). Paratype: 1 ♂, 2 ♀♀; 1 ♀, with the same label data as the holotype; 1 ♂, 1 ♀, labeled 'Sichuan, Chengdu City (成都市), Dayi County (大邑县), Xiling Town (西岭镇), Xilingxueshan (西岭雪山), Jiaoziping (椒子坪), an unnamed stream, 30°40′12′′N, 103°15′07′E; H: 1350m, 21.07.2022, R.-X. Jiang & F.-E. Li leg.' (GUGC).

Description.

Male. Body elongately elliptical (Fig. 1A ), black, with tarsi, tarsal claws and antennae reddish brown, tibiae brown. Dorsal surface punctuate and weakly shiny, covered with sparse short setae. Plastron setae is confined to following areas: head (both dorsal and ventral surface), prosternum, outer part of elytra (include epipleura), outer parts of mesoventrite, metaventrite and abdomen (except median part) and surface of femora.

Head (Fig. 2A ) wider than long, dorsal surface covered with dense short setae and large, sparse punctures, each puncture bearing a long seta, the interspaces between the punctures about 1.5-2 times of the diameters of punctures. Clypeus evenly punctate with large punctures and covered with long, sparse setae. Labrum transverse, shorter and slightly narrower than clypeus, covered with large punctures and long bristles at apical portion, anterior margin almost straight and anterolateral angles rounded. Antenna short, with eight antennomeres, antennomere I slightly longer than wide, with several short setae; antennomere II about as long as antennomere I, distinctly expanded, covered with several long setae, apical margin circled with short setae; antennomere III longer than wide; antennomeres IV-VII strongly transverse; antennomere VIII elliptical, elongate and strongly expanded, apex covered with long, dense setae.

Pronotum (Fig. 2B ) slightly wider than long, widest near basal 2/5. Anterior margin arcuate with angles moderately produced and acute. Lateral margins finely curved. Basal margin trisinuate, emarginate before scutellum, posterior angles obtuse. Surface shiny, finely covered with large punctures, each puncture bearing a long seta; surface near anterior angles microreticulate. Distinct longitudinal impression in the middle of the pronotum, basal 1/3 much wider than other parts; sublateral carinae from base to middle of pronotum, apical 1/2 curved, lateral parts of sublateral carinae distinctly convex. Prosternal process (Fig. 2D ) with rounded apex, disc without plastron setae, surface distinctly wrinkled.

Elytra (Fig. 2C ) about twice as long as wide, subparallel in basal 3/5, surface weakly wrinkled and covered with long, sparse setae. Each elytron with granulate carinae on strial intervals 5, 7, and 8; other intervals flat. Area from intervals to lateral margin covered with short, dense setae. Hind wings well developed.

Metaventrite (Fig. 2E ): surface of disc smooth, covered with large, sparse punctures, each bearing a long seta, sides partly covered with plastron setae. Median sulcus distinct, extending in posterior ca. 3/4, narrower and shallower from base to apex, base of median sulcus with a pair of small round impressions. Areas along coxal cavities with a series of shallow and anomalous impressions.

Disc of ventrites I-IV and anteriorly middle of ventrite V shiny, covered with small, sparse punctures, without plastron setae; other areas of ventrites covered with plastron setae. Apical area of ventrite V granulated, apical margin distinctly emarginate at middle.

Legs simple, femora swollen, surface covered with plastron setae; inner side of distal halves of tibiae with cleaning fringes; tarsi slightly shorter than tibiae; tarsal claws simple and strong.

Aedeagus (Fig. 3A-D ), slender and elongate, apex of median lobe asymmetrically arrowhead-like and weakly curved at middle, with a pair of short sclerotizations located at apical 1/5 and a pair of longer sclerotizations near the short sclerotizations, a much longer sclerotization located at middle of median lobe. Sternite IX (Fig. 3E ) with a tuft of short setae at middle of apical margin, paraproct with base slightly expanded and tortuous.

Measurements: CL: 3.29-3.35 mm; HL: 0.41-0.43 mm, HW: 0.56-0.59 mm; PL: 0.85-0.86 mm, PW: 0.91-0.97 mm; EL: 2.44-2.50 mm, EW: 1.24-1.32 mm.

Female: externally similar to the male, apex of sternite VIII rounded. Ovipositor as in Fig. 3F-H , stylus weakly curved at base, apex with three short finger-like sensilla; apex of coxite roundly broadened at outer margin, without sensilla; valvifer longer than coxite, fibula weakly sinuate with basal 1/5 expanded. Measurements: CL: 3.20-3.26 mm; HL: 0.42-0.47 mm, HW: 0.54-0.56 mm; PL: 0.82-0.83 mm, PW: 0.92-0.93 mm; EL: 2.38-2.43 mm, EW:1.22-1.24 mm.

Distribution.

China: Central Sichuan Province.

Biology.

All adults were collected from bottom crack of stone in small ravine stream (Fig. 9A-D ).

Etymology.

The specific epithet refers to the type locality, Sichuan Province; the name is treated as an adjective.

Comparative diagnosis.

Zaitzevia sichuanensis sp. nov. is more or less similar to Zaitzevia chenzhitengi Jiang & Wang, 2020 from Sichuan Province and Zaitzevia muchenae Bian & Zhang, 2022 from Yunnan Province. All three species share similar habitus, e. g. the relatively large and elongate oval body shape (both species> 3mm) and the wrinkled elytra. However, the new species can be well distinguished from Z. chenzhitengi by the following characters: 1) elytra weakly wrinkled (cf. distinctly wrinkled in Z. chenzhitengi ); 2) different form of elytra (wider in the new species of male, 1.24-1.32 mm in the new species, 1.06 mm in Z. chenzhitengi ); 3) different form of aedeagus (both two species with apex of median lobe arrowhead-like, but the median lobe shorter in Z. chenzhitengi , but much slender and with median lobe widely arrowhead in the new species); 4) different modification of areas between the lateral margins and the sublateral carinae (distinctly convex in the new species, and not convex in Z. chenzhitengi ). The new species can be distinguished from Z. muchenae by the much longer and wider longitudinal impression of pronotum and the obviously different form of aedeagus.

Figures

Figure 1. Dorsal habitus of Zaitzevia species, males A Zaitzevia sichuanensis sp. nov. B Zaitzevia fengtongzhaiensis sp. nov. C Zaitzevia yingzuijieensis sp. nov. Scale bar: 1 mm.

Figure 2. Diagnostic features of Zaitzevia sichuanensis sp. nov. A head, dorsal view B pronotum, dorsal view C elytra D prosternal process E metaventrite. Scale bars: 1 mm (C); 0.25 mm (A, B, D, E). Note: red arrow of C granulate carinae of elytra; red arrow of E impressions and median sulcus of metaventrite.

Figure 3. Diagnostic features of Zaitzevia sichuanensis sp. nov. A aedeagus, dorsal view B ditto, lateral view C ditto, ventral view D ditto, meidan lobe, dorsal view E dternite IX F ovipositor G, H apical part of ovipositor. Scale bars: 0.5 mm (A-C, E, F); 0.2 mm (D, G); 0.1 mm (H).

Figure 9. Habitat of Zaitzevia species A general environment of the type locality of Z. sichuanensis sp. nov.: Lengmugou Geopark B ditto, microenvironment C general environment of paratype: Xilingxueshan D ditto, microenvironment E general environment of the type locality of Zaitzevia fengtongzhaiensis sp. nov.: Fengtongzhai Nature Reserve F ditto, microenvironment G living adult of Z. fengtongzhaiensis sp. nov.