Elmomorphus ellipticus, 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 : 73-77

Elmomorphus ellipticus sp. nov.

urn:lsid:zoobank.org:act:33A6B2FB-9E56-43BC-9DEB-9028CF572398

Figs 33–34 , 37A , 110B

Differential diagnosis

Elmomorphus ellipticus sp. nov. ( Fig. 33 ) belongs to a group of species characterised by the presence of plastron on the dorsal cranial surface (except for a triangular or semicircular area on the vertex), on the anterior and sometimes also posterior angles of the pronotum, and on the lateral sides of the elytra. Elytral punctures are scattered over the entire surface and striae are absent. Within this group of species, E. ellipticus , together with E. corpulentus sp. nov., E. montanus , E. paramontanus sp. nov. and E. prosternalis , may be recognised by the presence of plastron only on the anterior angles of the pronotum. Elmomorphus ellipticus differs from the species mentioned above in the body shape, which is widest before the elytral midlength ( Fig. 33 ) but is broadest around or behind the elytral midlength in the other species ( Figs 31 , 40 ).

Moreover, the lateral plastron bands on the elytra are wider in E. ellipticus sp. nov., each covering about half of the elytron width (measured at elytral midlength), whereas in the other species it covers at most one-third of the elytron width. Elmomorphus ellipticus is smaller (TL: ♂ 2.71 mm (n=1), ♀♀ 2.79–3.01 mm (n =2)) than E. paramontanus sp. nov. (TL: ♂♂ 2.90–3.33 mm (3.07± 0.12, n= 26), ♀♀ 2.88–3.35 mm (3.20 ± 0.14, n =9)). Further differences between E. ellipticus and E. corpulentus sp. nov. are listed under the latter species. Aedeagus as in Fig. 34 . Bursa copulatrix with large microsclerites, in lateral portions bearing spines ( Fig. 37A ).

Etymology

The epithet is a Latin adjective in the nominative singular meaning elliptical, referring to the oval body shape.

Type material

Holotype

CHINA – Guangxi Autonomous Region • ♂; “CHINA: Guangxi 1993 10 km N Liuzhou , 10.11., 200m leg. Schönmann (18)”; IAECAS.

Paratypes

CHINA – Guangxi Autonomous Region • 2 ♀♀; same collection data as for holotype; NMW.

Type locality

China, Guangxi Autonomous Region, Liuzhou Prefecture, ca 10 km northeast of Liuzhou City, 3 km northwest of Shanmenjiang Forest Station; small stream, ca 1.5–2.0 m wide, slowly flowing through dense vegetation of small shrubs and some abandoned rice fields, ca 150–200 m a.s.l. (CWBS 40; Jäch & Ji 1995).

Description

Measurements (mm): TL: ♂ 2.71 (n =1), ♀♀ 2.79–3.01 (n=2); PL: ♂ 0.63 (n =1), ♀♀ 0.63–0.70 (n=2); PW: ♂ 1.19 (n =1), ♀♀ 1.22–1.28 (n =2); EL: ♂ 2.08 (n=1), ♀♀ 2.16–2.31 (n=2); EW: ♂ 1.43 (n=1), ♀♀ 1.46–1.53 (n= 2); PhL: 0.52 (n =1); PrL: 0.34 (n=1).

Body oval, slender, moderately convex ( Fig. 33 ). Integument black; mouth parts, antennae, trochanters, and tarsi reddish brown, remaining parts of legs dark brown; dorsum with fine, bronze metallic sheen. Pubescence consists of short, sparse decumbent yellowish setae. Dorsal plastron present on head except for triangular area on vertex, on anterior angles of pronotum, and lateral portions of elytra. Ventral plastron absent on prosternal process, median part of metaventrite, and middle of ventrites 1–2.

Dorsal head surface with round setiferous punctures, slightly smaller than eye facet, separated by ca 1–2 × puncture diameters; plastron on almost entire surface except for small triangular area on vertex. Labrum transverse, anterior margin feebly emarginate, exposed portion microreticulate, with small setiferous punctures. Anterior margin of clypeus straight. Eyes oval, protruding from head outline, interfacetal setae short; ID: ♂ 0.37 mm (n =1), ♀♀ 0.38–0.39 mm (n=2); APD/ID: ♂ 2.02 (n =1), ♀♀ 2.06–2.07 (n =2). Antennae 10-segmented, densely setose.

Pronotum transverse, weakly convex, widest at base, PW/PL: ♂ 1.87 (n=1), ♀♀ 1.83–1.92 (n =2); rim of anterior margin as wide as two eye facets, interrupted in middle; lateral sides convergent, slightly rounded; anterior angles protruding, acute; surface smooth, with round punctures; plastron present on anterior angles, posteriorly reaching beyond pronotal midlength. Prosternal process wider than long, lateral and posterior edges rounded; lateral margins raised, without clusters of long setae; median keel moderately arcuate. Scutellum as long as wide, with round punctures. Metaventrite covered with plastron, except for moderately convex, posteriorly narrowed median part; clusters of long setae absent; lateral margin of metaventral process raised and delimited by shallow longitudinal groove. Elytra oblong oval, moderately convex, widest at second third, EL/EW: ♂ 1.45 (n =1), ♀♀ 1.48–1.51 (n=2); dorsal surface finely microreticulate, with round setiferous punctures scattered over surface. Plastron in lateral bands almost reaches elytral base, expanded posteriorly, covering about half of elytron width (along elytral midlength). Tibiae straight; protibia ca 1.2× as long as protarsus; PrTL/PL: ♂ 1.19 (n =1), ♀♀ 1.09–1.19 (n =2). Terminal protarsomere longer than all preceding tarsomeres combined.

Ventrites covered with plastron, except for middle of ventrites 1–2; females with short longitudinal keel before apex of ventrite 5. Aedeagus ( Fig. 34 ): phallobase rather long, expanded proximally, PhL/PrL: 1.53 (n= 1); parameres slender, curved ventrad in apical half, apices narrowly rounded (lateral aspect); penis rounded apically (lateral aspect). Bursa copulatrix with large microsclerites, in lateral portions bearing spines ( Fig. 37A ).

Secondary sexual dimorphism

Females are recognisable by the presence of a short longitudinal subapical keel on ventrite 5.

Distribution

China (Guangxi) ( Fig. 110B ).

Figures

Fig. 33. Elmomorphus ellipticus sp. nov., paratype, male from type locality (NMW), TL: 2.71 mm.

Fig. 34. Elmomorphus ellipticus sp. nov., holotype (IAECAS), aedeagus. A. Lateral aspect. B. Ventral aspect. Scale bar: 0.1 mm.

Fig. 37. Bursa copulatrix and vagina. A. Elmomorphus ellipticus sp. nov., paratype from type locality (NMW). B. Elmomorphus mazzoldii sp. nov., paratype from type locality (NMW). Scale bar: 0.1 mm.

Fig. 110. Distribution maps.A. Elmomorphus corpulentus sp. nov.B. E. ellipticus sp. nov.C. E. mazzoldii sp. nov. D. E. bryanti Hinton, 1935. E. E. prosternalis Hinton, 1935. F. E. montanus (Grouvelle, 1913).

Fig. 31. Elmomorphus corpulentus sp. nov., holotype, male (IAECAS), TL: 3.32 mm.

Fig. 40. Elmomorphus paramontanus Kodada, Selnekovič & Jäch sp. nov., paratype, male from type locality (NMW), TL: 3.10 mm.