Elmomorphus calvus, 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 : 55-59

Elmomorphus calvus sp. nov.

urn:lsid:zoobank.org:act:384803E1-F693-4257-94BB-F785C824F6B4

Figs 23–24 , 28B , 109C

Differential diagnosis

Elmomorphus calvus sp. nov. ( Fig. 23 ) is characterised by the presence of plastron on the frontoclypeus, the anterolateral portions of the vertex and pronotum, and the lateral sides of the elytra. The elytral punctation consists of small scattered punctures and large punctures arranged in nine well-impressed striae. The pronotum is strongly convex with distinctly rounded lateral sides. Males possess conspicuous long erect setae on the labrum and small clusters of setae on the prosternal process, metaventrite and ventrite 5. The aedeagus is large, the phallobase is robust and strongly curved ( Fig. 24 ). Bursa copulatrix without sclerotised spines ( Fig. 28B ). A similar combination of characters is also shared by E. elmoides sp. nov., which differs in the smaller, TL: ♂♂ 2.47–2.68 mm (2.55 ± 0.06, n=10), ♀♀ 2.65–2.94 mm (2.81 ± 0.09, n=10) in E. elmoides versus TL: ♂♂ 3.17–3.35 mm (3.25 ± 0.06, n=7), ♀♀ 3.15–3.45 mm (3.30 ± 0.11, n =10) in E. calvus , and less convex body ( Fig. 21 ), the pronotum being less convex with straight lateral sides in E. elmoides versus strongly convex with rounded lateral sides in E. calvus , the pronotal plastron being present along the entire pronotal sides in E. elmoides versus restricted to the anterior half in E. calvus , the aedeagus with a slender and almost straight phallobase in E. elmoides ( Fig. 22 ) versus an expanded and strongly bent phallobase in E. calvus , and the bursa copulatrix possessing large sclerotised spines in E. elmoides ( Fig. 28A ), while in E. calvus , the spines are absent. Elmomorphus calvus may also resemble E. depressus sp. nov. and E. sulcatus sp. nov.; however, these species differ in the broader and more convex body shape ( Figs 27 , 39 ), the absence of conspicuous clusters of setae in males, and a differently shaped aedeagus.

Etymology

The epithet is a Latin adjective in the nominative singular meaning ‘hairless’, referring to the glabrous dorsal surface.

Type material

Holotype

VIETNAM – Vinh Phúc Province • ♂; “N-VIETNAM: Tam Dao (2) 1.- 8.6.1996 leg. Dembicky & Pacholatko ”; NMW.

Paratypes

CHINA – Guangxi Province • 1 ex.; “CHINA, GUANGXI A.R., 5.-9.iv.2013 SHIWANDA SHAN National Forest Park (forested river valley; in river) 21°54.4′N, 107°54.2′E, 290-360 m M.Fikáček, J.Hájek & J.Růžička leg.”, NMPC.

VIETNAM – Vinh Phúc Province • 8 ♂♂, 18 ♀♀; same collection data as for holotype; CKB, NMW .

Type locality

Vietnam, Vinh Phúc Province, Tam Dao.

Description

Measurements (mm): TL: ♂♂ 3.17–3.35 (3.25 ±0.06, n=7), ♀♀ 3.15–3.45 (3.30 ± 0.11, n =10); PL: ♂♂ 0.83–0.91 (0.86± 0.03, n= 7), ♀♀ 0.83–0.91 (0.87± 0.03, n=10); PW: ♂♂ 1.27–1.38 (1.33± 0.04, n= 7), ♀♀ 1.29–1.45 (1.38± 0.06, n= 10); EL: ♂♂ 2.34–2.47 (2.39± 0.04, n= 7), ♀♀ 2.31–2.54 (2.43 ± 0.08, n=10); EW: ♂♂ 1.46–1.59 (1.53±0.04, n=7), ♀♀ 1.50–1.66 (1.59± 0.06, n= 10); PhL: 1.12–1.21 (1.17± 0.03, n =7); PrL: 0.40–0.49 (0.45 ±0.03, n =7).

Body ovate ( Fig. 23 ), widest behind midlength of elytra, strongly convex dorsally, highest point at first quarter of elytral length. Colouration black, except for reddish brown mouthparts, antennae, trochanters, and tarsi, and brown proximal portions of tibiae. Vestiture consisting of short decumbent yellowish setae. Plastron present on cranium (except for semicircular area on vertex), on anterolateral portions of pronotum, and on lateral elytral bands. Ventral surface with thin plastron setae, except on prosternal process, and median parts of metaventrite and ventrites 1–2.

Head surface covered with plastron, except for semicircular area on vertex; with round setiferous punctures slightly smaller than eye facet, separated by 0.5–1.0 × facet diameter. Labrum transverse, anterior margin concave; surface microreticulate, with small punctures; males with conspicuous long setae, slightly shorter than terminal maxillary palpomere. Anterior margin of clypeus straight, with row of short dense setae. Eyes large, oval, protruding, interfacetal setae short; ID: ♂♂ 0.48–0.51 mm (0.49 ± 0.01, n=7), ♀♀ 0.52–0.54 mm (0.52 ± 0.01, n= 4). Antennae short, 10-segmented, densely covered with setae.

Pronotum strongly convex, wider than long, lateral sides distinctly rounded, PW/PL: ♂♂ 1.46–1.63 (1.55± 0.05, n =7), ♀♀ 1.54–1.65 (1.58± 0.04, n=10); surface smooth with round punctures slightly wider than those on head, separated by about half a puncture diameter; plastron present anterolaterally. Lateral margins of prosternal process straight and slightly raised, with conspicuous cluster of long erect setae in males; median keel flat; posterior edge rounded. Lateral margins of metaventral process raised; metaventral disc depressed in males, with two clusters of long and erect setae posteriorly, in females flat and without such clusters; glabrous area usually widening posteriorly. Scutellum wider than long, smooth, with several setiferous punctures. Elytra strongly convex, widest behind middle, EL/EW: ♂♂ 1.52–1.61 (1.57 ± 0.03, n =7), ♀♀ 1.47–1.57 (1.52 ±0.03, n =10); small punctures scattered over entire surface, large punctures arranged in nine well impressed striae, strial punctures confluent; plastron confined to two lateral bands, each extending from elytral side to fourth elytral stria. Tibiae straight, protibia ca 1.3× as long as protarsus, PrTL/PL: ♂♂ 0.95–1.08 (1.04 ±0.05, n=7), ♀♀ 0.95–1.05 (0.99± 0.03, n =10). Protarsus with terminal tarsomere nearly as long as all preceding segments combined; foreclaws long and slender, strongly curved.

Ventrites with plastron, except for median portions of ventrites 1–2. Intercoxal process wide, lateral margins raised, admedian keels distinct. Ventrite 5 evenly convex in both sexes, in males with two clusters of long, erect setae before apex, in females with short longitudinal subapical keel. Aedeagus ( Fig. 24 ): phallobase remarkably long and robust, strongly curved, PhL/PrL: 2.34–2.84 (2.62 ± 0.18, n= 7); parameres rather short, slightly curved ventrad, apices narrowly rounded (lateral aspect); penis curved ventrad apically; sclerotised fibula long and wide. Bursa copulatrix without sclerotised spines ( Fig. 28B ).

Secondary sexual dimorphism

Males with conspicuous long erect setae on labrum, prosternal process, median part of metaventrite and on ventrite 5; metaventral disc depressed. In females, metaventral disc flat; ventrite 5 with short longitudinal subapical keel.

Distribution

China (Guangxi), Vietnam ( Fig. 109C ).

Figures

Fig. 23. Elmomorphus calvus sp. nov., holotype, male (NMW), TL: 3.25 mm.

Fig. 24. Elmomorphus calvus sp. nov., holotype (NMW), aedeagus. A. Lateral aspect. B. Ventral aspect. Scale bar: 0.1 mm.

Fig. 28. Bursa copulatrix and vagina. A. Elmomorphus elmoides sp. nov., paratype from type locality (NMW). B. E. calvus sp. nov., paratype from type locality (CKB). C. E. depressus sp. nov., holotype (IAECAS). Scale bar: 0.1 mm.

Fig. 109. Distribution maps. A. Elmomorphus fusiformis sp. nov. B. E. elmoides sp. nov. C. E. calvus sp. nov. D. E. hongkong sp. nov. E. E. depressus sp. nov. F. E. sulcatus Kodada, Selnekovič & Jäch sp. nov.

Fig. 21. Elmomorphus elmoides sp. nov., paratype, male from Buon Luoi, Vietnam (CKB), TL: 2.55 mm.

Fig. 22. Elmomorphus elmoides sp. nov., paratype from type locality (CKB), aedeagus. A. Lateral aspect. B. Ventral aspect. Scale bar: 0.1 mm.

Fig. 27. Elmomorphus depressus sp. nov., holotype, female (IAECAS), TL: 3.58 mm.

Fig. 39. A. Elmomorphus prosternalis Hinton, 1935, holotype (BMNH), prosternal process and median part of metaventrite. B. E. montanus (Grouvelle, 1913), syntype, male (MNHN), prosternal process and median part of metaventrite. C. E. montanus, syntype (MNHN), aedeagus, lateral aspect. D. Same, ventral aspect, detail of parameres and penis. E. Same, ventral aspect. Scale bars: 0.1 mm.