Elmomorphus montanus ( Grouvelle, 1913 )

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 : 86-87

Elmomorphus montanus ( Grouvelle, 1913)

Figs 39B–E , 110F

Dryopidius montanus Grouvelle, 1913: 116 (original description).

Differential diagnosis

Elmomorphus montanus is characterised by the presence of a plastron on the dorsal cranial surface (except for the triangular area on the vertex), on the anterior pronotal angles and on the lateral sides of the elytra. Elytral punctures are scattered over the entire surface, and longitudinal striae are absent. This combination of characters is also shared by E. ellipticus sp. nov., E. corpulentus sp. nov. and E. paramontanus sp. nov. The lateral plastron bands on the elytra extend from just behind the elytral base and cover about one-third of each elytron width (measured at elytral midlength), while in E. corpulentus the plastron bands anteriorly do not reach the basal elytral fourth; in E. ellipticus , the plastron bands are distinctly wider and cover about half of the elytron width. Elmomorphus montanus resembles E. paramontanus , which can be separated by the shorter phallobase and longer parameres: PhL/PrL in E. montanus 2.30 ( Fig. 39C–E ), while is 1.37–1.81 (1.57± 0.11, n=25) in E. paramontanus sp. nov.

Type material

Syntype

INDIA – Arunchal Pradesh State • 1 ♂; “ Yambung 1100 ft. Ind. Mus. Abor Exp . 14.1.[19]12. Kemp, 2608/9, bank of stream, under stones”; MNHN.

Remarks

Right elytron broken in anterior third; four tarsomeres on right foreleg missing; right middle leg missing; four tarsomeres of right hindleg missing. The specimen has been remounted, and the aedeagus has been dissected by the third author. According to the original description, there are two syntypes. We were unable to locate the second syntype (sex unknown), which might be deposited in the Zoological Survey of India (Calcutta, India), but all our requests remained unanswered.

Type locality

India, Arunachal Pradesh, Yambung.

Redescription of syntype

Dimensions: TL 3.35 mm; PL 0.75 mm; PW 1.50 mm. Body elongate oval, moderately convex; black, mouth parts, antennae, trochanters, and tarsi reddish brown. Plastron present on dorsal cranial surface (except for small triangular part on vertex), anterior pronotal angles, and on lateral portions of the elytra. Plastron on entire ventral surface, except on prosternal process, median part of metaventrite, and middle of first two ventrites.

Cranial surface with round setiferous punctures of the size of an eye facet, separated by ca 1–2 × puncture diameters; plastron covering dorsal surface except for triangular area on vertex. Labrum transverse, exposed portions microreticulate, with setiferous punctures; setae moderately long, decumbent.

Pronotum transverse, widest at base, about twice as wide as long; surface smooth with round setiferous punctures subequal to those on head; plastron present on anterior angles and posteriorly reaching pronotal midlength; anterior angles protruding and deflexed; lateral sides weakly rounded in posterior half and weakly concave in anterior half. Lateral side of prosternal process moderately raised and delimited medially by deep longitudinal groove; median keel weekly arched ( Fig. 39B ); clusters of erect setae absent. Scutellum longer than wide, smooth, with several setiferous punctures. Metaventrite covered with plastron, except for posteriorly widened median part; disc moderately convex, irregularly punctate ( Fig. 39B ); clusters of erect setae absent. Elytra widest in the middle, EL/EW: 1.60, round setiferous punctures similar to those on pronotum; plastron forming two lateral bands, almost reaching elytral base, slightly widening posteriad, covering about one-third of elytron width (measured at elytral midlength); area without plastron smooth, not reticulated.

Ventrites covered with plastron, except on middle of ventrites 1–2. Ventrite 5 arcuate at apex. Aedeagus ( Fig. 39C–E ): phallobase robust, long, PhL/PrL: 2.30; parameres wide and short, weakly curved ventrad, apices broadly rounded (lateral aspect); penis rounded apically; sclerotised fibula long and slender.

Secondary sexual dimorphism

Female unknown.

Distribution

North-eastern India (Arunachal Pradesh) ( Fig. 110F ).

Figures

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.

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).