Elmomorphus parabrevicornis, 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 : 30-35

Elmomorphus parabrevicornis sp. nov urn:lsid:zoobank.org:act:4E9FE872-0589-4FB7-83A7-9430AAA6D4F7

Figs 10 , 11A–B , 12C , 108C

Differential diagnosis

Elmomorphus parabrevicornis sp. nov. ( Fig. 10 ) is characterised by having a plastron on the entire cranial surface, along the lateral sides of the pronotum, and the entire surface of the elytra. Males possess conspicuous long setae arranged in a transverse row on the labrum and in clusters on the prosternal process, the median part of the metaventrite, and the apex of ventrite 5. The phallobase is remarkably long and slender ( Fig. 11A–B ). The proximal and distal part of the bursa copulatrix has many small sclerotised spines ( Fig. 12C ).

A similar combination of characters is also known in E. amamiensis Nomura, 1959 from Japan, which is smaller, TL: ♂♂ 2.80–2.99 mm (2.91 ± 0.06, n =9), ♀♀ 3.09–3.22 mm (3.16± 0.05, n=7) in E. amamiensis versus TL ♂♂ 3.04–3.18 mm (3.12 ± 0.07, n =4), ♀♀ 3.27–3.47 mm (3.38± 0.09, n =6) in E. parabrevicornis sp. nov., and has distinctly fewer spines in the bursa copulatrix (see Fig. 12C , and Kodada et al. 2021: fig. 9e). Elmomorphus brevicornis and E. auripilosus sp. nov. also resemble E. parabrevicornis , while males of these species differ in having only several longer inconspicuous and hardly discernible setae on the labrum, prosternal process, median part of the metaventrite and ventrite 5. Elmomorphus auratus sp. nov. and E. horaki sp. nov. have a similar plastron distribution, but these species do not possess any clusters of long setae in males and have a distinctly shorter phallobase, PhL: 1.10–1.19 mm (n=3) in E. parabrevicornis versus up to 0.64 mm in E. auratus and 0.45 mm in E. horaki .

Etymology

The epithet, an adjective, refers to the high morphological similarity with E. brevicornis .

Type material

Holotype

CHINA – Hunan Province • ♂; “CHINA: SW-Hunan 1993 SW Huitong , 7.11., Umg. Guangping , 350m leg. Schillhammer (16) [CWBS 37]”; IAECAS.

Paratypes

CHINA – Hunan Province • 1 ♂, 1 ♀; same collection data as for holotype; CKB, NMW • 1 ♀; same collection data as for holotype, but “leg. L. JI ” (16) [CWBS 37]; NMW • 2 ♂♂; “ CHINA: SW Hunan, 1993, SW Huitong , 7. 11., Umg. Guangping , 400 m, leg. Schönmann (14) [CWBS 35]”; NMW. – Anhui Province • 1 ♀; “ CHINA: Anhui Huang Shan 50km W Tunxi , 29.10.1997 Yi Xian Shan , 350 - 400m leg. M. Wang (CWBS 290)”; NMW. – Fujian Province • 1 ♀; “ CHINA: FUJIAN, Chong’an Wuyi Shan , 3 km NW Wuyi Gong 300 m, 17.1.1997, leg. H.Schönmann (CWBS 246)”; NMW • 1 ♀: “ CHINA: FUJIAN, Chong’an Wuyi Shan , 3 km W Da’an 500 m, 19.1.1997, leg. Ji & Wang (CWBS 250)”; NMW. – Guangdong Province • 2 ♀♀; “ CHINA: Guangdong Prov. Chebaling - Siqian rd ., 24°41′11″N 114°07′17″E 7.11.2001, ca. 270 m Jäch & Komarek (CWBS 480)”; CKB, NMW .

Type locality

China, Hunan Province, Huaihua Prefecture, Huitong County, Guangping Township; river, slowly flowing, with riffle areas, ca 3–5 m wide, slightly polluted; 350 m a.s.l. (CWBS 37; Jäch & Ji 1995).

Description

Measurements (mm): TL ♂♂ 3.04–3.18 (3.12 ±0.07, n=4), ♀♀ 3.27–3.47 (3.38 ± 0.09, n=6); PL ♂♂ 0.70–0.78 (0.74 ±0.03, n =4), ♀♀ 0.75–0.81 (0.79± 0.02, n =6); PW ♂♂ 1.19–1.29 (1.23± 0.04, n= 4), ♀♀ 1.24–1.37 (1.29 ±0.04, n =6); EL ♂♂ 2.34–2.44 (2.38 ±0.05,n =4), ♀♀ 2.47–2.65 (2.59 ± 0.07, n= 6); EW ♂♂ 1.47–1.53 (1.50± 0.03, n= 4), ♀♀ 1.52–1.69 (1.61 ± 0.06, n= 6); PhL: 1.10–1.19 (n =3); PrL: 0.39–0.43 (n=3).

Body oblong-ovate, moderately convex dorsally, widest behind midlength of elytra ( Fig. 10 ). Colouration dark brown to black; mouthparts, antennae, and legs reddish brown. Pubescence consisting of short decumbent yellowish setae. Dorsal plastron present on entire dorsal surface, except for median part of pronotum; ventral plastron missing on prosternal process and median part of metaventrite.

Head covered with plastron on cranial surface; punctures round setiferous, their diameter smaller than eye facet diameter, separated by 0.75–1.00 × puncture diameter. Labrum transverse, anterior margin slightly rounded; anterolateral angles rounded; exposed part microreticulate, with small setiferous punctures; setae in males conspicuously long and erect. Anterior margin of clypeus slightly emarginate. Eyes oval, moderately protruding, interfacetal setae short; ID: ♂♂ 0.36–0.37 mm (0.37 ± 0.00, n =4), ♀♀ 0.40– 0.43 mm (0.41± 0.01, n =6). Antennae 10-segmented. Terminal maxillary palpomere fusiform, lateral sensory area located laterally on distal half.

Pronotum transverse, PW/PL: ♂♂ 1.58–1.72 (1.66± 0.06, n=4), ♀♀ 1.59–1.68 (1.64± 0.03, n= 6), plastron present on wide lateral portions reaching level of second elytral row; median part smooth; entire surface densely punctate, distance between punctures less than half a puncture diameter; bead of anterior margin twice as wide as eye facet, interrupted in middle; anterior angles protruding, acute; lateral sides convergent, straight to slightly rounded in dorsal aspect. Hypomeron widest behind middle in lateral aspect. Prosternal process with lateral edges divergent and rounded; posterior edge rounded; lateral margins raised; median keel moderately arcuate. Scutellum longer than wide, surface smooth, with several setiferous punctures. Median part of metaventrite flat to slightly convex; metaventral process with lateral margins raised, each delimited medially by deep longitudinal groove. Elytra elongate oval, entirely covered with plastron, moderately convex dorsally, widest behind middle, EL/EW: ♂♂ 1.55– 1.62 (1.58± 0.03, n=4), ♀♀ 1.53–1.71 (1.60 ± 0.06, n =6); surface microreticulate, small setiferous punctures scattered over entire surface and large round punctures arranged in nine longitudinal rows; diameter of large punctures decreasing towards elytral apices. Tibiae straight to slightly curved; protibia ca 1.3× as long as protarsus; PrTL/PL: ♂♂ 1.14–1.26 (1.18± 0.05, n =4), ♀♀ 1.07–1.08 (1.08± 0.00, n= 6). Terminal segment of protarsus slightly longer than combined length of preceding tarsomeres.

Ventrites entirely covered with plastron. Ventrite 5 in males convex anteriorly, apex triangularly emarginate, with two clusters of long setae; in females evenly convex, with minute excision at apex. Aedeagus ( Fig. 11A–B ): phallobase long and slender, expanded proximally, PhL/PrL: 2.59–2.89 (n =3); parameres strongly curved ventrad in apical half, apices narrowly rounded (lateral aspect); penis slightly expanded apically, rounded in lateral aspect; sclerotised fibula absent. Ovipositor: valvifers long, flattened; coxites asymmetrical, right one ca 1.40 × as long as left one. Proximal and distal part of bursa copulatrix with large number of sclerotised spines, especially distally ( Fig. 12C ). Sternite VIII with long anterior strut, slightly shorter than ovipositor.

Secondary sexual dimorphism

Males can be easily recognised by the conspicuous long setae on the labrum, prosternal process, and median part of the metaventrite. Moreover, the male ventrite 5 is strongly deflexed behind the base, emarginate at the apex, and possesses two clusters of long setae near the apex.

Distribution

China (Fujian, Guangdong, Hunan) ( Fig. 108C ).

Figures

Fig. 10. Elmomorphus parabrevicornis sp. nov., holotype (IAECAS), male, TL: 3.12 mm.

Fig. 11. A. Elmomorphus parabrevicornis sp. nov., holotype (IAECAS), aedeagus, lateral aspect. B. Same, ventral aspect. C. E. auripilosus sp. nov., paratype from Vietnam, Tam Dao (CKB), aedeagus, lateral aspect. Scale bar: 0.1 mm.

Fig. 12. Bursa copulatrix and vagina. A. Elmomorphus striatellus Delève, 1968, Cuc Phuong, Vietnam (CKB). B. E. siamensis Kodada, Selnekovič & Jäch sp. nov., paratype, Umphang, Thailand (CKB). C. E. parabrevicornis sp. nov., paratype from type locality (NMW). Scale bar: 0.1 mm.

Fig. 108. Distribution maps. A. Elmomorphus striatellus Delève, 1968. B. E. siamensis Kodada, Selnekovič & Jäch sp. nov. C. E. parabrevicornis sp. nov. D. E. auripilosus sp. nov. E. E. auratus sp. nov. F. E. horaki Kodada, Selnekovič & Jäch sp. nov.