Elmomorphus vietnamensis, 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 : 184-188

Elmomorphus vietnamensis sp. nov.

urn:lsid:zoobank.org:act:64F099FB-5D19-4F60-9820-06D6556B9D2E

Figs 90 , 91B–C , 114F

Differential diagnosis

Elmomorphus vietnamensis sp. nov. ( Fig. 90 ) is characterised by having the dorsal plastron confined to small areas on the frontoclypeus around the antennal insertions. The elytral striae are composed of large, deeply impressed punctures. The pronotal surface is smooth, not microreticulate as in E. schillhammeri sp. nov. and E. globosus sp. nov. The absence of microgranules on the pronotal disc and elytra and the absence of long erect setae on the labrum, prosternal process, and metaventrite in males separate this species from E. ovalis sp. nov. and E. minutus sp. nov. The surface of the vertex is smooth and not microreticulate as in E. jii sp. nov. The microreticulation of the elytra is formed by irregular polygonal meshes, whereas in E. schoenmanni sp. nov. it is formed by transverse lines. The pronotum is moderately convex, with the anterior angles moderately deflexed. The phallobase and parameres are rather long and slender ( Fig. 91B–C ) (PhL/PrL: 2.02 ± 0.13).

Etymology

The epithet is a Latin adjective in the nominative singular referring to Vietnam.

Type material

Holotype

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

Paratypes

VIETNAM – Vinh Phúc Province • 8 ♂♂, 4 ♀♀, 4 ex.; same collection data as for holotype; CKB, NMW .

Type locality

Vietnam, Vinh Phúc Province, Tam Dao.

Description

Measurements (mm): TL: ♂♂ 3.14–3.34 (3.27± 0.06, n=9), ♀♀ 3.36–3.47 (3.41± 0.05, n=4); PL: ♂♂ 0.75–0.85 (0.80 ± 0.03, n= 9), ♀♀ 0.80–0.85 (0.82 ±0.02, n=4); PW: ♂♂ 1.48–1.61 (1.55± 0.04, n= 9), ♀♀ 1.55–1.66 (1.59± 0.04, n =4); EL: ♂♂ 2.39–2.52 (2.47± 0.04, n =9), ♀♀ 2.55–2.63 (2.59 ± 0.03, n =4); EW: ♂♂ 1.74–1.92 (1.85± 0.05, n= 9), ♀♀ 1.85–1.95 (1.92± 0.04, n= 4); PhL: 0.72–0.83 (0.78± 0.03, n =9); PrL: 0.35–0.41 (0.39 ±0.02, n =9).

Body broadly oval, widest before midlength of elytra; dorsum moderately convex ( Fig. 90 ). Colour dark brown to black, mouthparts and antennae reddish brown; trochanters, tarsi, and distal portions of femora usually dark brown. Pubescence on head, pronotum and elytra consisting of very short and sparse yellowish setae. Plastron on dorsum confined to small areas around antennal insertions; on venter confined to median part of prosternum, prosternal process, and median part of metaventrite.

Head surface with weak microreticulation in anterior portion and with minute microgranules in lateral portions around eyes; round punctures smaller than eye facets, separated by 1.0–1.5 × puncture diameter. Plastron confined to small areas around antennal insertions. Anterior margin of clypeus straight. Labrum microreticulate on exposed portion, with minute round setiferous punctures; setae of equal length in both sexes. Eyes slightly protruding from head outline, interfacetal setae short. Antennae 10-segmented, densely setose.

Pronotum transverse, PW/PL: ♂♂ 1.88–2.00 (1.95± 0.04, n=9), ♀♀ 1.90–2.00 (1.95± 0.04, n= 4). Surface smooth, with round setiferous punctures and rather inapparent microgranules on lateral portions; plastron absent. Anterior rim as wide as two eye facets; anterior angles strongly deflexed, produced anteriorly; lateral pronotal sides weakly rounded. Hypomeron widest behind middle, covered with plastron. Prosternum covered with plastron, except on prosternal process and narrow triangular area before prosternal process. Lateral edges of prosternal process divergent, straight; posterior edge rounded; lateral portions broad, flat, separated from median portion by distinct, deeply impressed narrow ridges; median keel flat; prosternal process without groups of long setae in males. Metaventrite covered with plastron, except for posteriorly widened, convex median part; without groups of long setae in males. Elytra broad, strongly convex, widest before middle, EL/EW: ♂♂ 1.30–1.39 (1.34 ±0.03, n= 9), ♀♀ 1.32–1.38 (1.35± 0.02, n =4). Surface with distinct microreticulation formed by irregular meshes, and small punctures scattered over entire surface; nine deep longitudinal striae with large round punctures, separated by 0.5–1.0 × puncture diameter; plastron absent. Tibiae slightly curved, PTL/PL: ♂♂ 0.94– 1.03 (0.97 ±0.03, n=9), ♀♀ 0.88–0.98 (0.92 ± 0.04, n= 4). Protarsus about 0.7× as long as protibia; terminal protarsomeres slightly shorter than three previous tarsomeres combined.

Ventrites covered with plastron, except for middle of ventrite 1 between two admedian keels. Ventrite 5 in males with minute, often inapparent triangular excision at apex; in females arcuate at apex with short longitudinal keel. Aedeagus ( Fig. 91B–C ); phallobase rather long, proximally expanded, PhL/PrL: 1.76–2.29 (2.02± 0.13, n =9); parameres long, slightly curved ventrad in distal third, apices pointed in lateral view; penis slender; sclerotised fibula slender. Bursa copulatrix without spiny microsclerites.

Secondary sexual dimorphism

Male ventrite 5 with minute triangular excision at apex, in female rounded with short longitudinal keel.

Distribution

Vietnam ( Fig. 114F ).

Figures

Fig. 90. Elmomorphus vietnamensis sp. nov., holotype, male (NMW), TL: 3.27 mm

Fig. 91. A. Elmomorphus schoenmanni sp. nov., holotype (IAECAS), aedeagus, lateral aspect. B. E. vietnamensis sp. nov., paratype from type locality (CKB), aedeagus, lateral aspect. C. Same, 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.