Elmomorphus minutus, Selnekovič & Jäch & Kodada, 2024

Selnekovič, Dávid, Jäch, Manfred A. & Kodada, Ján, 2024, Taxonomic revision of the genus Elmomorphus Sharp, 1888. II. Redescription of the genus and review of the species from India, Nepal, Bhutan, Myanmar, China, Thailand, Laos, Cambodia, and Vietnam (Coleoptera: Dryopidae), European Journal of Taxonomy 957, pp. 1-229 : 175-178

Elmomorphus minutus sp. nov.

urn:lsid:zoobank.org:act:45ECC443-5495-42DF-80A0-F0CF2F1E79FA

Figs 85–86 , 114C

Differential diagnosis

Elmomorphus minutus sp. nov. ( Fig. 85 ) is characterised by having the dorsal plastron confined to small areas around the antennal insertions. Elytral striae are distinct. The pronotal surface is not microreticulate, unlike in E. schillhammeri sp. nov. and E. globosus sp. nov. The cranial surface is smooth, without microgranules, which separates E. minutus from E. ovalis sp. nov., along with the smaller body size (TL in E. ovalis : ♂♂ 3.80–3.84 mm (n =2), ♀♀ 3.87–4.13 mm (n=3), in E. minutus : ♂♂ 2.92–3.27 mm (3.10 ± 0.15, n= 4), ♀ 3.58 mm (n =1)). Males bear long erect setae or setal clusters on the labrum, prosternal process, and metaventrite, which distinguish this species from E. schoenmanni sp. nov., E. jii sp. nov., and E. vietnamensis sp. nov. Moreover, the elytral microreticulation is formed by irregular polygonal meshes, while in E. schoenmanni , it is formed by coarse transverse lines. The phallobase and parameres are rather long and slender ( Fig. 86 ), PhL/PrL: 2.05–2.40 (2.14 ± 0.17, n= 4).

Etymology

The epithet ‘minutus’ is a Latin adjective in the nominative singular meaning ‘small, little’. The name refers to the small body size.

Type material

Holotype

CHINA – Yunnan Province • ♂; “CHINA: Yünnan, Xishuangbanna ca. 10km NW Menglun 7.11.1999, ca. 700 - 800 m leg. Jäch, et al. (CWBS 360)”; IAECAS.

Paratypes

CHINA – Yunnan Province • 1 ♂; same collection data as for holotype; NMW • 1 ♂; “ CHINA: Yünnan, Xishuangbanna , ca. 10 km NW Menglun 7.11.1999, ca. 700 m leg. Jäch, et al. (CWBS 359)”; CKB • 1 ♀; “ CHINA: Yünnan, Xishuangbanna , ca. 20 km W Jinghong 11.11.1999, ca. 1000 m leg. Jäch, et al. (CWBS 374)”; NMW • 1 ♂; “ CHINA: Yünnan, Simao Pref., 35 km SW Mojiang , 19.11.1999, ca. 1000 m Schönmann & Wang (CWBS 395)”; NMW .

Remarks

A single male from Zhejiang (CWBS 420) is very similar to that of E. minutus sp. nov. Examination of more specimens and molecular data may provide evidence that this specimen respresents an undescribed species.

Type locality

China, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Mengla County, Menglun Town, ca 10 km NW of Menglun, along the road from Menglun to Mengyang, ca 700 m a.s.l.; Wushiwu He (= River Fifty-five), ca 3–5 m wide, flowing through primary forest in steep valley (CWBS 360; Jäch & Ji 2003).

Description

Measurements (mm): TL: ♂♂ 2.92–3.27 (3.10 ±0.15, n=4), ♀ 3.58 (n =1); PL: ♂♂ 0.81–0.86 (0.85 ± 0.02, n =4), ♀ 0.91 (n =1); PW: ♂♂ 1.45–1.64 (1.53± 0.09, n=4), ♀ 1.69 (n=1); EL: ♂♂ 2.11– 2.40 (2.25 ± 0.13), ♀ 2.65 (n =1); EW: ♂♂ 1.69–1.98 (1.81 ± 0.12, n=4), ♀ 1.98 (n =1); PhL: 0.82–0.92 (0.87 ± 0.04, n=4); PrL: 0.38–0.43 (0.41 ± 0.02, n=4).

Body oval, moderately convex ( Fig. 85 ). Integument black; mouthparts, antennae, and tarsi reddish brown, remaining parts of legs brown. Pubescence consisting of short and sparse yellowish setae. Plastron covering small anterolateral portions on frontoclypeus and ventral surface, except prosternal process, and middle of metaventrite and ventrite 1.

Dorsal surface of head with round punctures, finely microreticulate, without microgranules; diameter of punctures smaller than an eye facet, punctures separated by ca 1.0–1.5 × puncture diameter. Labrum transverse, anterior margin broadly emarginate, exposed portion microreticulate, with small setiferous punctures; setae in males distinctly longer than in females. Anterior margin of clypeus straight. Eyes oval, with short interfacetal setae, ID: ♂♂ 0.51–0.55 mm (0.52 ± 0.02, n= 4), ♀ 0.63 mm (n=1), APD/ ID: ♂♂ 1.63–1.69 (1.66± 0.03, n=4), ♀ 1.54 (n =1). Antennae 9-segmented, densely setose.

Pronotum moderately convex, PW/PL: ♂♂ 1.71–1.90 (1.81 ± 0.08, n= 4), ♀ 1.86 (n =1); rim of anterior margin as wide as two eye facets, interrupted in middle; anterior angles prominent, acute; lateral sides convergent, slightly rounded; surface smooth, lacking microgranules, punctures round. Prosternal process wider than long, lateral edges divergent, straight; posterior edge rounded; lateral portions wide, rather flat, in males with long setae anteriorly; median keel moderately arcuate. Scutellum wider than long, with round punctures. Metaventrite with median part flat, posteriorly widened, in males with two groups of long setae. Elytra oval, widest before middle, EL/EW: ♂♂ 1.21–1.31 (1.24± 0.04, n =4), ♀ 1.34 (n =1). Dorsal surface microreticulate; small punctures scattered; large, deep punctures arranged in nine longitudinal rows, distance between punctures ca 1–2 × puncture diameters. Tibiae slightly curved; protibia ca 1.5 × as long as protarsus; PrTL/PL: ♂♂ 0.95–1.04 (1.00± 0.04, n=4), ♀ 0.95 (n= 1). Terminal protarsomeres as long as three preceding tarsomeres combined.

Ventrites covered with plastron, except for median part of ventrite 1. Ventrite 5 apically rounded. Aedeagus ( Fig. 86 ): phallobase long, slightly expanded proximally, PhL/PrL: 2.05–2.40 (2.14 ± 0.17, n= 4); parameres slender, short in relation to phallobase, slightly curved ventrad, apices very narrowly rounded (lateral aspect); penis apically narrowly rounded; sclerotised fibula very short.

Secondary sexual dimorphism

Males with groups of long setae on labrum, lateral rims of prosternal process, and median part of metaventrite.

Distribution

China (Yunnan) ( Fig. 114C ).

Figures

Fig. 85. Elmomorphus minutus sp. nov., paratype, male from China, locality CWBS 395 (CKB), TL: 3.10 mm.

Fig. 86. Elmomorphus minutus sp. nov., paratype from China, locality CWBS 395 (CKB), aedeagus. A. Lateral aspect. B. Ventral aspect. Scale bar: 0.1 mm.

Fig. 114. Distribution maps. A. Elmomorphus globosus sp. nov. B. E. ovalis Kodada, Selnekovič & Jäch sp. nov. C. E. minutus sp. nov. D. E. jii sp. nov. E. E. schoenmanni sp. nov. F. E. vietnamensis sp. nov.