Zaitzevia xiongzichuni Jiang & Wang, 2020

Jiang, Ri-Xin & Wang, Shuo, 2020, Two new species of the genus Zaitzevia Champion, 1923 from China (Coleoptera Elmidae: Macronychini), Zootaxa 4852 (2), pp. 231-238 : 234-235

Zaitzevia xiongzichuni Jiang & Wang sp. nov.

Figs 1B , 3 , 4 D–F, H, J, M–N

Type material. Holotype: CHINA: ♂, labeled ‘China: Yunnan, Lincang City (ĎṄḿ), Manwan Town (ŌṀÄ), Shuibatou Village ( AE ṊẆḣ), H: 2100m, 20.04.2020, Zi-Chun Xiong leg.’ ( QUST) . Paratype: CHINA: 2 ♀♀, with the same label data as the holotype ( QUST) .

Description. Male. Body elongate elliptical ( Fig. 1B ), black, tibiae, tarsi, tarsal claws and antenna reddishbrown, dorsal surface punctuate, covered with sparse setae. Silvery sericeous tomentum is confined to following areas: head (both dorsal and ventral surface), pronotum, prosternum, outer part of elytra (include epipleura), outer parts of mesosternum, metaventrite and abdomem (except median part) and surface of femora.

Head ( Fig. 3A ), wider than long, dorsal surface covered with dense short setae and sparse big punctures, each puncture with a much longer seta, the interspaces between the punctures about 2–3 times diameters of punctures. Clypeus evenly punctate with large punctures and covered with sparse long setae. Labrum transverse, shorter and broader than clypeus, covered with big punctures and long bristles at apical portion, anterior margin almost straight and anterolateral angles rounded.a Antenna ( Fig. 3C ) much short, with eight antennomeres; antennomere I slightly longer than wide, with several short setae; II much longer than I, expanded, covered with several long setae, apical margin circled with short setae; III longer than wide; IV-VII strongly transverse; VIII elliptical, elongate and strongly expanded, apex covered with dense long setae.

Pronotum ( Fig. 3B ) slightly wider than long, widest near basal 1/3. Anterior margin arcuate with angles moderately produced and acute. Lateral margins finely curved. Basal margin trisinuate, emarginated before scutellum, posterior angles near orthogonal. Surface shiny, covered with sparse big punctures, each puncture with short seta; surface near apical angles microreticulate. Distinct longitudinal impression in the middle of the pronotum; sublateral carinae from base to 1/2, slightly curved. Prosternal process ( Fig. 3D ) with rounded apex.

Elytra ( Fig. 3F ) about 1.5 times as long as wide, subparallel in anterior 3/5, surface smooth and covered with sparse long setae. Each elytron with granulate carinae on strial intervals 5, 7 and 8, other intervals flat. Area from intervals to lateral margin covered with dense short setae. Hind wings well developed.

Metaventrite ( Fig. 3E ), surface smooth and without setae on disc; sides with silvery sericeous tomentum. Median sulcus longitudinal and distinct, extending from posterior margin to ca. 4/5 of metasternum. Sides of median sulcus with a pair of distinct subglobular grooves near posterior margin; and a pair of anomalous shallow grooves near mesocoxae.

Abdomen with 5 visible sternites, sides of sternites with silvery sericeous tomentum. Sternite V and VI granulated; apex of sternite V ( Fig. 4M ) emarginate.

Legs simple, femora swollen, surface covered with sericeous tomentum; inner side of tibiae with cleaning fringes; tarsi about as long as tibiae; tarsal claws simple.

Aedeagus ( Figs 4 D–F), slender and elongate, near symmetrical, apex of median lobe cuspidal.

Measurements: BL: 3.05 mm; HL: 0.34 mm, HW: 0.57 mm; PL: 0.77 mm, PW: 0.90 mm; EL: 2.28 mm, EW: 1.26 mm.

Female: externally similar to the male, larger in size, apex of sternite V ( Fig. 4N ) rounded. Ovipositor as Fig. 4J . Measurements: BL: 3.12–3.43 mm; HL: 0.32–0.36 mm, HW: 0.57–0.60 mm; PL: 0.80–0.93 mm, PW: 0.92–1.01 mm; EL: 2.32–2.50 mm, EW: 1.35–1.50 mm.

Distribution. China: Yunnan Province.

Biology. All adults were collected in the bottom crack of a stone in a ravine stream.

Etymology. This species is named in honor of our friend Mr. Zi-Chun Xiong, who collected the new species and donated it to us for study.

Comparative diagnosis. Zaitzevia xiongzichuni sp. n. can easily distinguished from other Zaitzevia species which distribute around Southwest China. The Indian species Z. solidicornis is much smaller (≤ 2 mm). The Burmese species Z. malaisi share similar habitus character with Z. xiongzichuni sp. nov., but Z. malaisi with curved lateral carinae on pronotum, while the lateral carinae are straight at base part in Z. xiongzichuni sp. nov.. The posterior angles of Z. malaisi is obtuse, while the new species with posterior angles near orthogonal. those two species also could be distinguished by the different form of aedeagus. The Vietnamese species Z. pocsi much smaller (1.62 mm) than the new species, and with arrowhead-like apex of median lobe.

Figures

FIGURE 1. A. Dorsal habitus of Zaitzevia chenzhitengi sp. nov., male; B. Dorsal habitus of Zaitzevia xiongzichuni sp. nov, male.

FIGURE 3. Diagnostic features of Zaitzevia xiongzichuni sp. nov. A. Head, dorsal view; B. Pronotum, dorsal view; C. Antenna; D. Prosternal process; E. Metaventrite; F. Elytra.

FIGURE 4. Diagnostic features, A–C, G, I, K–L, Zaitzevia chenzhitengi sp. nov.; D–F, H, J, M–N, Zaitzevia xiongzichuni sp. nov.. A & D. Aedeagus, dorsal view; B & E. Aedeagus, lateral view; C & F. Aedeagus, ventral view; G–H. Abdominal segment 9 and speculum gastrale, male; I–J. Ovipositor; K & M. Sternite V, male; L & N. Sternite V, female.