Lamiogethes unditibiis, Liu & Yang & Huang & Cline & Sabatelli & Audisio, 2020

Liu, Meike, Yang, Xingke, Huang, Min, Cline, Andrew Richard, Sabatelli, Simone & Audisio, Paolo, 2020, Five new species of Lamiogethes Audisio & Cline from China (Coleoptera Nitidulidae: Meligethinae), Zootaxa 4728 (1), pp. 63-76 : 72-73

Lamiogethes unditibiis sp. n.

( Figs. 1d , 2 g–h, 3c, g, j, 5)

Diagnosis. Vaguely similar in external body shape and color to the common Palearctic species Lamiogethes persicus ( Faldermann, 1835) (in the L. difficilis species group: Audisio 1993). Dorsal surface closely and markedly punctate (spaces between pronotal and elytral punctures ca. 1.2–1.6× their diameter), with smooth and shining interspaces; elytra together ca. 1.2× wider than pronotum, without distinguishable traces of transverse strigose sculpturing. Pronotum with vaguely trapezoidal shape, and rather straight lateral sides, at least in posterior two thirds ( Fig. 1d ). Pubescence on pronotum and elytra sparse, golden-yellowish, distinct, each individual seta distinctly shorter (ca. 0.80×) than antennomere 2. Body uniformly dark brown; legs and antennae uniformly brown to orange brown. Male protarsi moderately wide, ca. 0.9× as wide as maximum width of antennal club ( Fig. 1d ), ratio WFTA/LFTA ≈ 0.30. Male metatibiae slightly undulate along inner edge ( Fig. 3j ). Male genitalia distinctively shaped, with elongate, subparallel-sided and very deeply incised tegmen ( Fig. 2g ), aedeagal median lobe moderately large, ca. 2× longer than wide, maximum width proximad, and with characteristic short sword-tip-shaped distal apex ( Fig. 2h ).

Description. Size (male holotype): body length 2.20 mm, width 1.40 mm.

Body color and pubescence: uniformly dark brown, tegument shiny. Legs and antennae uniformly brown to orange brown. Pubescence pale golden, moderately long and sparse, not concealing tegument, each individual seta ca. 0.80× as long as second antennomere ( Fig. 1d ).

Dorsal habitus: Clypeus with nearly truncate anterior margin. Dorsal punctures on pronotum rather fine and deep, each puncture separated from another by ca. 1.2–1.6 diameter; space between punctures smooth and shining. Dorsal punctures on elytra rather large, separated by ca. 1.1–1.4 diameters; space between punctures smooth and shining. Ratio LPR1/LELY = 0.60; ratio WPR1/LPR1 = 1.79; ratio WPR2/LPR1 = 1.74; ratio WPR2/WPR1 = 0.93; ratio LELY/WELY = 1.02; ratio WPR1/WPRA = 1.70; ratio WPR1/WELY = 0.96; ratio WPR2/WELY = 1.05.

Ventral habitus: combined outer edges of antennal grooves almost straight, parallel-sided along most of length. Prosternal process only slightly wider than length of antennal club, only with moderately impressed and dense punctation. Male metaventrite moderately impressed, with a shallow semi-circular transverse impression, occupying nearly the posterior two-thirds, and with a couple of barely distinct and scarcely raised small tubercles slightly before middle. Last ventrite with a small, shining tubercle in middle of posterior edge.

Appendages: antennae rather short ( Fig. 1d ); ratio ANLE/HWEA = 0.75; ratio CLLE/W10J = 1.25; ratio L03J/ W03J = 2.00; ratio L03J/L02J = 0.75; ratio L03J/L04J = 2.00; ratio WFTA/LFTA ≈ 0.29; ratio LETI/WITI ≈ 2.90. Protibiae with a series of 3–5 moderately sharp teeth, increasing in size from first to penultimate, shaped nearly as in the common Palearctic species L. morosus (Erichson, 1845) ( Fig. 3g ). Metatibiae slightly undulate along inner side ( Figs. 1d , 3j ).

Male genitalia: distinctively shaped, with elongate and subparallel-sided tegmen ( Fig. 2g ), widest in middle, medial distal excision deep, narrowly U-shaped (ratio DTIN/LETE ≈ 0.43), inner margins of excision without gib- bosities close to base; ratio LETE/WITE ≈ 1.51. Median lobe of aedeagus large and long, ratio LEAE/WIAE ≈ 2× longer than wide ( Fig. 2h ), exhibiting maximum width close to proximal base, with abruptly narrowed, sword-tipshaped distal apex, and markedly concave proximal apex.

Female: The female of this species exhibits protarsi slightly narrower than in male (ratio WFTA/LFTA ≈ 0.24), and simple (not undulate) metatibiae. Metaventrite almost flat, without distinct impression or longitudinal stria.

Ovipositor: middle-sized, with rather pointed distal apex, not darkened distad, and peculiarly long and narrow subapical styli ( Fig. 3c ).

Variation: body size 2.10–2.20 mm (length) and 1.35–1.40 mm (width), and sexually dimorphic shape of protarsi and metatibiae.

Examined material. Holotype, ♂: China: Chongqing, Jinyun Mt. ,[ca. 700 m a.s.l., ca. 29°28’12”N 106°12’0”E], 26.iv.1939, without further data, ( IZAS) . Paratypes: same data as holotype, 1 ♂, 3 ♀♀ ( IZAS) .

Distribution. S China (Chongqing) ( Fig. 5 ).

Host-plants. Unknown, but probably among Lamiaceae .

Habitat. Locality data indicate that this species prefers the edges of middle-low altitude, sparsely forested and bushy areas.

Phenology. The few available specimens were collected at the end of April, which likely indicates adult activity at least from late April to at least early June.

Etymology. The specific epithet is derived from the Latin unda (= wave), and tibia (= tibia), due to the slightly sinuate inner edge of the metatibiae in males ( Fig. 3j ).

Taxonomic remarks. As reported above, this new species is vaguely similar in external shape to L. persicus from Europe (see Audisio 1993), as well as to other E Palearctic species of the genus, but is likely more closely relat- ed to the three other species described above. This species shares with them an overall similar body shape and size, type of punctation, and peculiarly sword-tip-shaped distal apex of the median lobe of aedeagus. Male specimens of the other species are markedly different in possessing a longer median lobe of aedeagus and markedly different tegmen. Lamiogethes unditibiis sp. n. could represent a species of the group more closely related to L. ancestor (from E Shaanxi), which exhibits markedly different tegmen, but vaguely similar median lobe of the aedeagus ( Figs. 2 g–h herein and figs. 24–25, p. 178, in Kirejtshuk 1992).

Figures

FIGURE 1. Habitus of Lamiogethes spp.: a, L. falcatus sp. n. male from China, Sichuan; b, L. hastipenis sp. n., male from China, Hubei; c, L. sagittalis sp. n., male from China, Shaanxi; d, L. unditibiis sp. n., male from China, Chongqing; e, L. limaelytralis sp. n., male from China, Sichuan. Scale bar: 0.5 mm (Figs. a–e).

FIGURE 2. Male genitalia (tegmen and median lobe of aedeagus, dorsal view) of Lamiogethes spp.: a–b, L. falcatus sp. n., male from China, Sichuan; c–d, L. hastipenis sp. n., male from China, Hubei; e–f, L. sagittalis sp. n., male from China, Shaanxi; g–h, L. unditibiis sp. n., male from China, Chongqing; i–j, L. limaelytralis sp. n., male from China, Sichuan. Scale bar: 0.2 mm (Figs. a–j).

FIGURE 3. Female genitalia (ovipositor, ventral view) of Lamiogethes spp. (a–c): a, L. falcatus sp. n. from China, Sichuan (female not selected as paratype); b, L. sagittalis sp. n., female from China, Shaanxi; c, L. unditibiis sp. n., female from China, Chongqing. Protibiae of Lamiogethes spp. (d–h): d, L. falcatus sp. n., male from China, Sichuan; e, L. hastipenis sp. n., male from China, Hubei; f, L. sagittalis sp. n., male from China, Shaanxi; g, L. unditibiis sp. n., male from China, Chongqing; h, L. limaelytralis sp. n., male from China, Sichuan. Metatibiae of Lamiogethes spp. (i–j): i, L. falcatus sp. n., male from China, Sichuan; j, L. unditibiis sp. n., male from China, Chongqing. Scale bar: 0.2 mm (Figs. a–j).

FIGURE 5. Distribution map of Chinese Lamiogethes treated herein.