Elmomorphus horaki Kodada, Selnekovič & Jäch, 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 : 42-47

Elmomorphus horaki Kodada, Selnekovič & Jäch sp. nov.

urn:lsid:zoobank.org:act:0482B698-E016-4BE2-889E-A59114D69998

Figs 16–17 , 18C , 108F

Differential diagnosis

Elmomorphus horaki sp. nov. ( Fig. 16 ) is characterised by the presence of plastron on the entire cranial surface, lateral bands of the pronotum, and the entire elytral surface. The same pattern is also found in E. amamiensis , E. auratus sp. nov., E. auripilosus sp. nov., E. brevicornis , and E. parabrevicornis sp. nov. In contrast to E. amamiensis and E. parabrevicornis , males of E. horaki sp. nov. do not possess any clusters of long setae on the labrum, prosternal process, or metaventrite. In E. horaki , the phallobase is relatively short compared to the parameres ( Fig. 17 ) (PhL/PrL: 1.63–1.83 (1.75± 0.06, n = 10), while in E. amamiensis , E. auripilosus , E. brevicornis , and E. parabrevicornis it is distinctly longer (PhL/ PrL at least 1.8). Elmomorphus horaki rather closely resembles E. auratus , from which it differs in the wider pronotal plastron bands (each covering about one-third of the pronotal width), smaller body size, the more parallel-sided elytra ( Fig. 16 ), narrowed and apically rounded parameres ( Fig. 17 ), and the spines of the bursa copulatrix being arranged in an apical cluster and a more or less distinct, lateral row ( Fig. 18C ).

Etymology

The epithet is a proper noun in the genitive case honouring Jan Horák, a Czech entomologist who kindly provided interesting material from Thailand.

Type material

Holotype

THAILAND – Chiang Mai Province • ♂; “NW Thailand CHON [CHOM] THONG 24-27.IV. 1991 J.Horak lgt.”; NMW.

Paratypes

CAMBODIA • 24 ex.; “CAMBODIA, PREAH VIHEAR, CHOAM KHSANT , 01.- 12.05.2012 LOCAL COLLECTOR”; CKB, NMW.

THAILAND – Chiang Mai Province • 9 ♂♂, 15 ♀♀, 30 ex.; same collection data as for holotype; CKB, NMB, NMW • 2 ♂♂; “ THAILAND occ. bor. 24.- 28.04.1991 Chom Thong Jan Farkač leg.”; CKB, NMB • 2 ♂♂, 2 ♀♀; “ NE Thailand 23.-27. 4. 1991 Chom Thong S. Bilý leg.”; CKB, NMB • 12 ex.; “ N-THAILAND: Ch. Mai, Chom Thong , 24.- 26.4.1991 leg. Pacholatko ”; CKB • 3 ex.; “ NW THAILAND, 1991 Chom Thong 24.-27.4. 18.26 N 98.41 E L.Dembický leg.”; NMB, NMW • 3 ex.; “ N-THAILAND NW Chiang Mai, Pai City , 29.4.1993 Pacholatko & Dembicky ”; NMW • 1 ex.; “ NW-THAILAND Chiang Mai ( Zoo ) 23.5.- 1.6.1988 leg. Malicky (Licht [at light])”; NMW • 10 ex.; “ THAILAND: 10km N Chiang Dao Mae Ping , 28.- 29.6.1991 400m, 19°27′N 99°00′E Malicky & Chantaramongkol ”; NMW • 9 ex.; “ THAILAND, Mae Ping 19.- 20.6.1991 leg. Malicky (Licht [at light])”; NMW • 3 ex.; “ THAILAND, Mae Ping 16.- 20.6.1991 leg. Malicky ”; NMW. – Loei Province • 2 ex.; “ Thailand: Loei, 3 km W Phu Kradung , 8.III.1994, Lam Phong Ko , WDS-A-1029 William D. Shepard leg.”; CSS. – Mae Hong Son Province • 1 ex.; “NW Thailand 9.-16.V. MAE HONG SON 1991 Ben Huei Po 1600m leg. P.Pacholatko ”; NMW • 1 ex.; “THAI 1-8. V.1992 Ban-si Lang Mae Hong Son J.Horak leg.”; NMW. – Songkhla Province • 17 ex.; “ S-THAILAND, 10.6.1993 06°59′N 100°22′E 13km W Hat Yai , 50m Ban Ko Muang , Malicky ”; NMW. – Tak Province • 18 ♂♂, 9 ♀♀; “Thai 26.IV.- 6.V. 1991 Umphang 500 m, 16° 04′N 98° 53′E, Vít Kubáň leg. | Thailand 91 Thanon Thong Thai , D. Král, V. Kubáň [labels written in various styles]”; CKB, NMB, NMW. – Uthai Thani Province • 1 ex.; “ THAILAND Jan.1989 240km nr. Bangkok 110m,leg. Thielen | 25km nw. Lan-Sak Lichtfang [light trap]”; NMW .

VIETNAM • 1 ex.; “S-VIETNAM Nam Cat Tien Nat.Park 1. – 15.5. 1994 Pacholatko & Dembicky ”; NMW .

Additional material examined

MYANMAR – Sagaing Region • 1 ex.; “ Myanmar, ( Burma ), Ban Mauk Reg ., 270km N Sagaing, 200- 750m, 05.V.-25. VI. 2012 24°23′50.88′′N 95°51′25.49[′′]E, leg. local collectors”; CPE .

Type locality

Thailand, Chiang Mai Province, Chom Thong.

Description

Measurements (mm): TL: ♂♂ 2.21–2.67 (2.49 ± 0.13, n =10), ♀♀ 2.21–2.89 (2.61± 0.20, n=10); PL: ♂♂ 0.52–0.64 (0.59 ± 0.03, n =10), ♀♀ 0.52–0.66 (0.60 ± 0.05, n=10); PW: ♂♂ 0.94–1.14 (1.06 ± 0.06, n =10), ♀♀ 0.94–1.23 (1.08 ±0.09, n =10); EL: ♂♂ 1.77–2.08 (1.99± 0.10, n =10), ♀♀ 1.74–2.31 (2.10 ±0.16, n=10); EW: ♂♂ 1.09–1.33 (1.23± 0.07, n= 10), ♀♀ 1.07–1.35 (1.23± 0.10, n= 10); PhL: 0.41–0.45 (0.43 ± 0.02, n=10); PrL: 0.23–0.26 (0.25 ± 0.01, n=10).

Body elongate oval, widest behind midlength of elytra, moderately convex dorsally, highest point at anterior third of elytra ( Fig. 16 ). Body black, except for mouthparts, antennae, tarsi and trochanters reddish-brown, remaining parts of legs brown. Pubescence consisting of short thin decumbent yellowish setae arising from round punctures. Plastron present on entire cranial surface, lateral sides of pronotum, and entire elytral surface. Ventral plastron present on entire surface, except prosternal process and median part of metaventrite.

Cranial surface entirely covered with plastron; round setiferous punctures of about 0.75 × of eye facet diameter, separated by 0.5–1.0 × puncture diameter. Labrum transverse, anterior margin straight, anterolateral angles rounded, surface on exposed portion microreticulate with setiferous punctures, setae short and decumbent, equal in length in both sexes. Anterior margin of clypeus straight with a row of short thin setae. Eyes oval, moderately protruding, ID: ♂♂ 0.34–0.38 mm (0.36 ±0.01, n =10), ♀♀ 0.32– 0.39 mm (0.36 ± 0.02, n =10); APD/ID: ♂♂ 1.90–2.12 (2.01 ±0.07, n=10), ♀♀ 1.81–2.10 (1.95± 0.09, n= 10). Antennae short, 10-segmented.

Pronotum transverse, widest at base, strongly convex, basally flattened; PW/PL: ♂♂ 1.76–1.84 (1.80 ± 0.03, n=10), ♀♀ 1.74–1.88 (1.82 ± 0.05, n=10). Pronotal surface with round setiferous punctures; punctures slightly larger than those on head, separated by ca 0.75–1.00 × puncture diameter; pronotal disc smooth. Lateral plastron bands on pronotum of same width on anterior and posterior parts and distinctly narrowed in the middle; in anterior and posterior portions separated by ca one-third of pronotal width. Anterior pronotal angles deflexed, protruding and acute; pronotal sides converging anteriorly, slightly curved along entire length. Prosternal process laterally and posteriorly rounded; lateral margins raised; median keel moderately raised. Scutellum longer than wide, smooth, with several small setiferous punctures. Lateral margins of metaventral process raised; metaventral disc flat, without plastron. Elytra ovate, convex, lateral sides diverging anteriorly and strongly converging posteriorly, widest point behind middle; EL/EW: ♂♂ 1.56–1.72 (1.62± 0.05, n= 10), ♀♀ 1.63–1.76 (1.71 ± 0.04, n=10). Elytral surface entirely covered with plastron; scattered small setiferous punctures and larger punctures arranged in nine longitudinal rows in weakly impressed striae; strial punctures separated by about half a puncture diameter. Tibiae straight; protibia slightly shorter than protarsus; PTiL/PL: ♂♂ 1.15–1.28 (1.21 ± 0.05, n= 10), ♀♀ 1.02–1.33 (1.19± 0.08, n= 10). Terminal protarsomere slightly longer than all preceding segments combined; foreclaws narrow, strongly curved, similar in both sexes.

Ventrites entirely covered with plastron. Intercoxal process with lateral margins flat; admedian keels inapparent. Ventrite 5 regularly convex in both sexes; apex triangularly emarginate in males, with several erect setae on both sides of emargination; in females with short longitudinal keel at apex. Aedeagus ( Fig. 17 ): phallobase rather short, PhL/PrL: 1.63–1.83 (1.75 ±0.06, n = 10); parameres curved ventrad, apices rounded (lateral aspect); penis narrowly rounded at apex; sclerotised fibula slender. Bursa copulatrix ( Fig. 18C ) with numerous minute spines in distal part, and with several larger scattered spines in proximal part.

Secondary sexual dimorphism

Females are on average slightly larger than males. Male ventrite 5 triangularly emarginate apically; female ventrite 5 with a short longitudinal keel at apex.

Distribution

Cambodia, Myanmar, Thailand, Vietnam ( Fig. 108F ).

Figures

Fig. 16. Elmomorphus horaki Kodada, Selnekovič & Jäch sp. nov., paratype, male from type locality (CKB), TL: 2.50 mm.

Fig. 17. Elmomorphus horaki Kodada, Selnekovič & Jäch sp. nov., aedeagus. A. Paratype from type locality (CKB), lateral aspect. B. Same, ventral aspect. C. Paratype from Umphang, Thailand (CKB), lateral aspect. D. Paratype from Umphang, lateral aspect. Scale bar: 0.1 mm.

Fig. 18. Bursa copulatrix and vagina. A. Elmomorphus auripilosus sp. nov., paratype from Cuc Phuong, Vietnam (CKB). B. E. auratus sp. nov., paratype from China, CWBS 246 (CKB). C. E. horaki Kodada, Selnekovič & Jäch 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.