Amphiops coelopunctatus, Fenglong, 2014

Fenglong, J. I. A., 2014, A revisional study of the Chinese species of Amphiops Erichson (Coleoptera, Hydrophilidae, Chaetarthriini), Journal of Natural History 48 (17), pp. 1085-1101 : 1089-1092

Amphiops coelopunctatus sp. nov.

( Figures 2E–J , and 5B )

Type locality

China, Hainan Island, Limushan Mountains , 550–750 m , 19°9.1–9.2 ′ N, 109°45–46 ′ E

Type material

Holotype male ( SYSU): China, Hainan island Limushan Mountains , 5 May 2011, 19°9.1–9.2 ′ N, 109°45–46 ′ E, 550–750 m, Fikáček and Zhao lgt . Paratypes: 1 male and 3 females ( SYSU), same data as holotype ; 1 male, 2 spec. ( NMPC): China, Hainan island, Limushan Mountaint , 19°9.1–9.2 ′ N, 109°45– 46 ′ E, 550–750 m, along the road, small streamlet in secondary forest with bamboo: among gravel and stones in a small pool, 5 May 2011, Fikáček and Zhao lgt .; 5 spec. ( NMPC): same locality data, but with habitat data as follows: exposed pools along the road partly connected to the stream; sparsely to densely overgrown by grass.

H I J

Diagnosis

Dorsum glabrous, black. Anterior margin of clypeus broadly truncate; head with sparse punctation, all punctures of the same size; lateral portions of pronotum with punctation identical to those on head, punctures on median portion finer; elytra without serial punctures, ground punctation similar to head, lateral punctures somewhat coarser than those on inner parts. Systematic punctures on head, pronotum and elytra of the same size as ground punctures. Lateral margin continuously curved to posterior margin, ( Figure 2F, I ), hence posterolateral angle absent. Mesofemora very narrowly separated. Metaventrite without a transverse ridge anteriorly. Mesofemora densely pubescent on basal third, metafemora glabrous, only pubescent along anterior margin on basal half. Aedeagus with median lobe broad, triangular apically, broadly notched behind apex on each side, gonopore situated apically; parameres as long as median lobe, almost parallel-sided, rounded apically, distinctly curved medially on inner face.

Description

Form and colour. Body strongly convex, broadly oval. Length 3.55–3.65 mm (holotype 3.60 mm), width 2.60–2.65 mm (holotype 2.65 mm). Black, lateral margin of pronotum yellowish brown. Maxillary palpomeres, labial palpomeres, antennae, legs and ventrites yellowish brown, ventral surface of mesoventrite and metaventrite yellowish brown to dark brown. Antennal club dark.

Head. About 1.75 × as wide as long. Glabrous, without microsculpture between punctures, with punctation consisting of single size of ground punctures mixed with some systematic punctures of the same size as ground punctures, intervals between punctures c.1.25–1.50 × the diameter of a puncture. Anterior margin of clypeus broadly truncate or slightly concave anteriorly. Frontoclypeal suture indistinct, sometimes undetectable. Mentum c.0.75 × as long as wide, with sparsely arranged systematic punctures, slightly emarginate anteriorly. Apical maxillary palpomere asymmetrical, longer than penultimate palpomere.

Thorax. Pronotum c.2.25 × as wide as long, median portion with finer and sparser punctures than those on head, lateral portion with coarser punctation consisting of single size of ground punctures intermixed with systematic punctures of the same size; intervals between punctures about c.1.5–1.7 × the diameter of a puncture mesally, c.1.2–1.4 × laterally. Posterolateral margin rounded, posterior angle unclear. Prosternum short, with a strong median carina. Scutellum longer than wide, with same punctures mesally as on pronotum. Elytra almost as high as long, ground punctures similar to head but somewhat coarser laterally, intervals between punctures c.1.3–1.5 × the diameter of a puncture mesally, c.1.1–1.2 × laterally; elytron with five series of setiferous punctures (systematic punctures) that are the same size as ground punctures, serial punctures absent. Mesoventrite gradually raised posteriorly to form a narrowly notched protuberance, mesocoxae very narrowly separated. Metaventrite slightly convex medially, without transverse carina anteriorly. Profemora and mesofemora densely pubescent on basal half, metafemora only pubescent anteriorly on basal half, with fine and sparse punctures beneath, without microsculpture between punctures.

Abdomen. Covered with hyaline mass. Visible part of first ventrite very short, without median carina, with marginal short and very fine setae anteriorly.

Aedeagus. Median lobe broad, triangular apically, broadly notched behind apex on each side, gonopore situated apically. Parameres as long as median lobe, almost parallel-sided, rounded apically, distinctly curved mesad on inner face. Phallobase slightly longer than parameres, abruptly narrowed medially ( Figure 5B ).

Differential diagnosis

The new species is close to A.coomani and A.globus based on the pronotum without distinct posterolateral corners, elytra without series of coarse punctures, head, pronotum and elytra with ground punctures of single size; metaventrite without a transverse carina anteriorly, and metafemora glabrous with fine punctures. It can be easily distinguished from these species by the dorsum with denser and coarser punctures, pronotum and elytra with systematic punctures of the same size as ground punctures, and median lobe of the aedeagus narrower, triangular apically, broadly notched behind apex on each side.

Etymology

The species name is a combination of Coelostoma , a genus of the hydrophilid tribe Coelostomatini , and the Latin punctatus. The name refers to the fact that the head, pronotum and elytral punctation of this new species are similar to the dorsal punctation of many Coelostoma species.

Biology

Aquatic. Part of type series was collected in an exposed pool connected to the stream and overgrown by grass, while the second part of the series was collected from the gravel on the side of a small streamlet shaded streamlet in the secondary forest c. 50 m from the exposed pool (Fikáček and Zhao, pers. comm.).

Distribution

China: Hainan.

Figures

Figure 2. Amphiops caristripus Jia. (A) Head and pronotum; (B) elytra, lateral margin; (C) elytral apex; (D) elytra. Amphiops coelopunctatus sp. nov. (E) Habitus; (F) head, pronotum and elytra base, lateral view; (G) elytra; (H) head; (I) pronotum and elytral base; (J) metasternum and abdomen.

Figure 5. Aedeagi. (A) Amphiops coomani; (B) Amphiops coelopunctatus; (C–F Amphiops mirabilis, from (C) Guangzhou, (E) Hainan and (D, F) Yunnan; (G, H) Amphiops mater from (G) Guangdong and (H) Yunnan.