Agraphydrus anhuianus ( Hebauer, 2000 )

Komarek, Albrecht & Hebauer, Franz, 2018, Taxonomic revision of Agraphydrus Régimbart, 1903 I. China and Taiwan (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4452 (1), pp. 1-101 : 21-23

Agraphydrus anhuianus ( Hebauer, 2000)

(Figs. 3, 85, 127)

Megagraphydrus anhuianus Hebauer 2000: 15 .

Agraphydrus anhuianus ( Hebauer, 2000) : Minoshima, Komarek & Ôhara 2015: 12.

Type locality. China, Anhui Prov., Huang Shan, Qi Yun Shan. near Yan Qian, 30 km W Huang Shan City ( CWBS 284).

Type material examined. Holotype Ƌ ( CASS): “ CHINA: Anhui, Huang Shan \ 30 km W Tunxi, 24.10. 1997 \ Qi Yun Shan, 500 m \ leg. M. Wang ( CWBS 284) | HOLOTYPUS \ Megagraphydrus \ anhuianus sp. n. \ des. F. Hebauer”. Paratypes: 23 exs. ( NMW): same sampling data.

An additional single female paratype from Hong Kong (University Campus, at light, 1996, leg. G. de Rougemont, NMW) does definitely not belong to A. anhuianus . It cannot be assigned to a certain species.

Differential diagnosis. This species belongs to the group of species with very distinct systematic punctures on anterior and posterior half of elytra. It shares angulate anterior clypeal margin with distinct median notch with A. activus . It differs from A. activus by presence of lateral subapical bulge on parameres. Distinct four rows of systematic punctures reaching or almost reaching anterior elytral margin are also present in A. decipiens , A. fikaceki , A. luteilateralis , A. malayanus , and A. thaiensis . These species differ from A. anhuianus and A. activus by evenly concave anterior clypeal margin. Agraphydrus luteilateralis and A. decipiens also differ by presence of eight antennomeres, smaller body size, and in features of aedeagus. Separated from A. malayanus and A. thaiensis by stout maxillary palpomeres and by features of aedeagus.

Description. Total length: 2.5̄ 2.9 mm; elytral width: 1.3̄ 1.5 mm; E.I.: 1.2̄1.3, P.I.: 2.2̄2.4, elytra 2.9̄3.1× as long as pronotum. Habitus broad, body evenly oval, strongly convex dorsally.

Coloration. Labrum, clypeus and frons black; clypeus with dark yellow, undefined, lateral margins; maxillary palpi unicolored yellow; pronotum and elytra black with diffuse, variably sized yellow margins; ventrites and legs black, femora dark brown.

Head. Clypeus with distinctly, evenly excised anterior margin; C.I.: 4.4, lateral length ratio clypeus/eyes = 1.9; microsculpture absent, except very narrow lateral seam, within yellow areas; ground punctures fine, distinctly impressed, interspaces 2× as wide as punctures, or wider on some areas; systematic punctures distinct. Eyes large but not protruding. Antennae with nine antennomeres. Maxillary palpi rather stout, 0.9̄1.0× as long as pronotum in midline, 0.9× as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.1, palpomere 4 almost symmetrical. Mentum with some moderately coarse punctures but absent from median area.

Thorax. Pronotal ground punctation as on head; systematic punctures moderately distinct. Elytral ground punctation slightly stronger than on head and pronotum, interspaces 1̄2× as wide as punctures; systematic punctures very distinct, loosely arranged in four rows, reaching anterior margin. Mesoventrite with a low bulge abruptly declining posteriorly, forming a triangle.

Legs (Fig. 85). Pubescence present on proximal 2/3 of profemur, slightly more extended on meso- and metafemur; hairlines straight.

Abdomen. Ventrite 5 with very shallow apical emargination, 6 µm deep.

Aedeagus (Fig. 127). Length: 0.46̄ 0.47 mm. Phallobase half as long as parameres (without manubrium), shorter than wide; margins evenly curving towards distinctly defined, moderately long, narrow manubrium; border between pigmented and unpigmented portion of ventral face indistinct. Parameres wide at base, narrowing apicad; lateral margin slightly sinuate in proximal 3/4, with distinct supapical bulge and very distinct excision distal to bulge; mesal margins evenly curved; apex obliquely flattened, with sharply pointed lateral projection; basal portion wide, extending to distal third of phallobase. Median lobe narrow, parallel-sided, narrowing weakly in apical third towards distinctly excised apex, not reaching apex of parameres; corona located slightly distally to midlength; basal apophyses long, distinctly bending laterad, extending to midlength of phallobase.

Ecology. Collected in 500 m a.s.l., in deep residual pools of largely dried out small stream with rocks, sand and gravel.

Distribution. China (Anhui), Thailand (Kampaeng Phet Prov.: Minoshima et al. 2015). The occurrence in Hong Kong is unconfirmed.

Agraphydrus arduus sp. n.

(Figs. 4, 86, 128)

Type locality. China, Yünnan Prov., Xishuangbanna Dai Autonomous Prefecture, Mengla County, Wushiwu He River , ca. 10 km NW Menglun Town ( CWBS 359 ).

Type material: Holotype Ƌ (CASS): “CHINA: Yünnan, Xishuangbanna \ ca. 10 km NW Menglun \ 7.11.1999, ca. 700 m \ leg. Jäch, et al. (CWBS 359)”. Paratypes: CHINA: Yünnan: 3 ♂♂, 5 ♀♀: (NMW); same sampling data; 7 ♀♀ (NMW): CWBS 360; 2 ƋƋ (NMW): CWBS 367; 8 exs. (NMW): CWBS 368; 1 ex. (NMW): CWBS 379; 1 Ƌ (NMW): CWBS 387; 1 Ƌ (NMW): CWBS 390; 2 ƋƋ (NMW): CWBS 400; 5 exs. (NMW): CWBS 394; 2 ♀♀ (NMW): CWBS 395; 1 ♀ (NMW): CWBS 404; 1 ♀ (NMW): CWBS 405; 3 ƋƋ, 2 E (NMW): CWBS 408; 1 ♀ (NMW): CWBS 409; 1 ♀ (ISNB): “Yunnan [hand-written] \ Coll. R.I.Sc.N.B., Chine | Agraphydrus sp.? \ prope orientalis \ mais ant. 9art. [hand-written]”; Guangdong: 7 exs.: (NMW): CWBS 457; ƋƋ (NMW): CWBS 458; 2 ƋƋ (NMW): CWBS 461; Hubei: 1 Ƌ (NMW): CWBS 547.

Differential diagnosis. This species belongs to the group of species with largely chagrinated clypeus and unicolored yellow maxillary palpomeres, together with A. connexus , A. gracilipalpis , A. igneus , A. orientalis , A. reticuliceps , A. schoenmanni , and A. umbrosus . It differs from A. orientalis by nine-segmented antennae and features of aedeagus. It shares similar habitus (elytra evenly oval), presence of chagrination on anterolateral angle of pronotum, and similar aedeagus (apex of parameres distinctly inflated) with A. igneus , differing mainly by elytral coloration (dark brown, or light brown with black sublateral band, versus unicolored ferruginous in A. igneus ) and slightly finer dorsal ground punctation. Evenly oval elytra and similar elytral coloration (with sublateral black band distinct in most specimens) are also present in A. connexus , A. schoenmanni and A. umbrosus , but A. arduus differs from these species distinctly by features of aedeagus.

Description. Total length: 1.9̄ 2.6 mm; elytral width: 0.8̄ 1.3 mm; E.I.: 1.4, P.I.: 2.1̄2.2, elytra 2.9̄3.2× as long as pronotum. Habitus evenly oval, moderately convex dorsally.

Coloration. Labrum brown; clypeus yellow with mesal infuscation or light brown to black, with yellow preocular patches about as wide as eye or slightly less wide; frons black; maxillary palpi unicolored yellow; pronotum with large, oval, blackish brown area on central region, with diffuse borders, broadly contacting posterior margin, variably extending laterad, with yellow lateral portions and narrow yellow anterior rim; elytra unicolored dark brown, or with large light brown central area, yellow lateral margins, and black sublateral band widening towards anterior margin, sutural area black or dark brown; ventrites black, legs dark brown. Individuals with unicolored dark brown to black head, pronotum and elytra occur.

Head. Clypeus with distinctly, evenly excised anterior margin; C.I.: 3.9, lateral length ratio clypeus/eyes = 1.8; clypeus almost entirely covered with microreticulation, but absent from postero-mesal area, also missing on frons in most specimens, rarely present on its anterior portion; ground punctures on clypeus obsolete, on frons very fine, weakly impressed, interspaces 2̄4× as wide as punctures; systematic punctures distinct. Eyes large but not protruding. Antennae with nine antennomeres. Maxillary palpi slender, 1.1× as long as pronotum in midline, 1.0̄1.1× as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.3̄1.4, palpomere 4 almost symmetrical. Mentum with fine, evenly distributed punctures, and microsculpture on anterolateral area.

Thorax. Pronotal ground punctation very fine to fine, weakly impressed, microreticulation present on anterolateral pronotal portion; systematic punctures distinct. Elytral ground punctation fine, slightly more distinct than on pronotum; systematic punctures distinct, arranged in four rows, rows 1̄3 not reaching anterior margin, composed of few punctures in posterior half of elytra; few additional coarse punctures present along lateral margins in some individuals. Mesoventrite with distinct median bulge on posterior half.

Legs (Fig. 86). Pubescence present on proximal 2/3 of profemur, on proximal 3/4 of meso- and metafemur; hairlines oblique on profemur, straight to slightly curved on meso- and metafemur.

Abdomen. Ventrite 5 with almost semicircular apical emargination, 10̄15 µm deep.

Aedeagus (Fig. 128). Length: 0.25̄ 0.34 mm. Phallobase about as long as parameres, as long as wide; margins abruptly bending towards triangular manubrium; border between pigmented and unpigmented portion of ventral face reaching midlength. Parameres with slightly sigmoid margins; apex delicate, inflated; basal portion weakly reaching into phallobase. Median lobe widest in midlength; ventral face delicate, with blunt or flat, rarely slightly indented apex, reaching or almost reaching apex of parameres; dorsal face subdivided into widely separated left and right half, distinctly shorter than ventral face; corona small, located between midlength and distal third; basal apophyses short, narrowly separated, extending to distal third of phallobase.

Remarks. The specimen from Hubei differs from individuals from Yünnan and Guangdong by unicolored dark brown elytra.

Ecology. Collected between 230 and 2150 m a.s.l., in rivers and streams, flowing through primary forests, shrubs, pine, oak, and Cunninghamia forest, cultivated land, paddy fields; also in canalized streams in crop fields and pastures, in small pools with moss and leaves, in pools with boulders and small particles of debris, and in the upwelling of a karst river.

Distribution. China (Guangdong, Hubei, Yünnan).

Etymology. arduus (Lat.) = steep. The name refers to the steep valley where the type specimen was collected.