Agraphydrus masatakai Minoshima, Komarek & Ôhara, 2015

Komarek, Albrecht & Hebauer, Franz, 2018, Taxonomic revision of Agraphydrus Régimbart, 1903 I. China and Taiwan (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4452 (1), pp. 1-101 : 48-51

Agraphydrus masatakai Minoshima, Komarek & Ôhara, 2015

(Figs. 32, 60, 77, 110, 152)

Agraphydrus masatakai Minoshima, Komarek & Ôhara 2015: 49 ff.

Type locality. Laos, Houaphanh Prov., Xam Noua , Ban Saleui.

Type material examined. Paratypes: CHINA: Guangdong: 9 exs. ( NMW): CWBS 487 ; Hainan: 1 Ƌ ( NMW), CWBS 205 ; Hong Kong: 6 exs. ( NMW), University Campus , at light, 1996 , leg. G. de Rougemont ”; 2 ƋƋ, 1 ♀ ( CFH, NMW), “ New Territory, Tai Po Kau Sp. Area , 11.I.1997, forest stream , leg. W.D. Shepard “WDS-

A-1245 A”. Yünnan: 17 exs. ( NMW): CWBS 354 ; 29 exs. (NMW, CFH): CWBS 357; 1 Ƌ (NMW): CWBS 359; 1 Ƌ (NMW): CWBS 360; 1 Ƌ (NMW): CWBS 361; 3 ƋƋ (NMW): CWBS 363; 17 exs. (NMW): CWBS 364; 1 Ƌ (NMW), CWBS 367; 1 Ƌ (NMW): CWBS 368; 1 Ƌ (NMW): CWBS 370; 22 exs. (NMW): CWBS 408; 1 ♀ (NMW), CWBS 387; 1 Ƌ (NMW): CWBS 388; 1 Ƌ (NMW), CWBS 397; 5 exs. (CFH, NMW): CWBS 396; 1 Ƌ (NMW), CWBS 394.

Type material from Laos, Malaysia and Thailand: see Minoshima et al. (2015).

Additional material examined. CHINA: Guangdong: 1 ex. ( NMW): CWBS 453 ; Hongkong: 1 ex. (CPA): Tai Om Shan, Lam Tsuen, leaf litter in stream, 18.II.2013 ; 1 ex. (CPA): Tai Mo Shan, 800 m a.s.l., in moss above stream, 2.II.2013; 1 ex. (CPA): Lantau Isl. , Tung Chung, leaf litter, at edge of stream, 17.III.2012 ; 1 ex. (CPA): Lantau Isl. , Tai O Valley, pool in dry stram, 10.I.2012 ; 2 exs. (CPA): Lantau Isl. , Mui Wo, 23.VI.2013 ; 2 exs. (CPA): Lantau Isl., Shek Pik Valley, stream, wet leaves, 26.I.2013; 1 ex. (CPA): Lantau Isl. , Ngong Ping, 26.XI.2011; Yünnan: 1 ♂, 2 ♀♀ ( NMW): CWBS 359 ; 1 Ƌ (NMW): CWBS 364; 2 ♀♀ (NMW): CWBS 368; 1 Ƌ (NMW): CWBS 396.

Differential diagnosis. This species belongs to the group of species with four rows of elytral systematic punctures, absence of clypeal microsculpture, nine-segmented antennae, unicolored maxillary palpomeres, and wide-stretched metafemoral pubescence, together with A. fikaceki , A. splendens , and A. chinensis . It differs from A. fikaceki by moderately distinct elytral systematic punctures with anteriorly abbreviated mesal series, from A. chinensis by larger eyes, wider clypeus, and presence of emargination on abdominal ventrite 5, from A. splendens by moderate (versus fine) pronotal and elytral ground punctures, and shape of maxillary palpi (shorter than pronotum; ratio palpomere 4:3 = 1.0̄1.2 (versus palpi longer than pronotum, ratio palpomere 4:3 = 1.4). It differs from all species of Agraphydrus by features of aedeagus.

Description. Total length: 2.2̄ 2.8 mm; elytral width: 1.3̄ 1.4 mm; E.I.: 1.2̄1.4, P.I.: 2.2̄2.3, elytra 3.1̄3.2× as long as pronotum. Habitus moderately broad, evenly oval, moderately convex dorsally.

Coloration variable. Labrum and lateral portions of clypeus rufous, mesal portion of clypeus and frons dark brown or black, or head entirely black; maxillary palpi unicolored yellow; pronotum unicolored dark brown, with decreasing intensity of coloration towards lateral margins, with four black mesal spots in lighter colored individuals, or pronotum completely black; elytra black or unicolored dark brown or rufous with indistinct dark brown areas on disc, with yellowish or light brown margins in some cases; in light colored individuals head usually darker than pronotum and elytra; ventrites dark brown to black; legs slightly lighter. Most individuals from China with black head, pronotum, elytra, and ventrites.

Head (Fig. 60). Clypeus with distinctly, evenly excised anterior margin; C.I.: 4.0, lateral length ratio clypeus/ eyes = 1.7; microsculpture absent, except some indistinct wrinkles on lateral edge; ground punctures moderately fine, interspaces 1̄3× as wide as punctures; systematic punctures moderately distinct. Eyes large, but not protruding, slightly oblong. Antennae with nine antennomeres. Maxillary palpi (Fig. 77) moderately slender, 0.8× as long as pronotum in midline, 0.8× as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.0̄1.2, palpomere 4 almost symmetrical. Mentum with fine but distinct, evenly distributed, punctures, without microsculpture.

Thorax. Pronotal ground punctation as on head; systematic punctures moderately distinct. Elytral ground punctation as on head and pronotum or slightly stronger, interspaces about as wide as punctures; systematic punctures moderately distinct, arranged in four rows, mesal rows 1̄3 with strongly reduced number of punctures, not reaching anterior margin. Mesoventrite with strong mesal bulge.

Legs (Fig. 110). Pubescence present on proximal 2/3 of profemur, on proximal 3/4 of meso- and metafemur; hairlines oblique on profemur, straight on meso- and metafemur.

Abdomen. Ventrite 5 with very shallow apical emargination, 4̄10 µm deep, absent in some individuals.

Aedeagus (Fig. 152). Length: 0.35̄ 0.50 mm. Phallobase about half as long as parameres, as wide as long or slightly wider; margins almost rectangularly bending towards distinctly delimited, moderately long manubrium; border between pigmented and unpigmented portion of ventral face very indistinct, reaching midlength, concealed by basal portion of parameres in many cases. Parameres with very wide base distinctly narrowing towards apex; margins sigmoid, lateral margin with strong subapical extension in distal third, rarely indistinct and more dorsally directed; apex with distinct, sharp, beak-like lateral extension; ventral face indistinct, shorter than dorsal face; base of dorsal face reaching halflength of phallobase. Dorsal face of median lobe very slender, parallel-sided in distal half, with bluntly rounded apex, not reaching apex of parameres; ventral face distinctly shorter and wider; corona located in midlength; basal apophyses widely separated, inclining laterad, extending to midlength of phallobase.

Ecology. Collected between sea level and 1500 m a.s.l.; in ponds, in rivers and streams flowing through agricultural land, primary and degraded forests; in the upwelling of a karst river with large boulders and debris; in pools with fine sand, pools with leaves; in a strongly insolated stream with moss; in springs.

Distribution. China (Guangdong, Hainan, Hong Kong, Yünnan); Laos, Malaysia, Thailand ( Minoshima et al. 2015).

Agraphydrus niger sp. n.

(Figs. 33, 61, 78, 111, 153)

Type locality. China, Fujian Prov., Jianyuan Prefecture, Chong’an City Region, ca. 1 km W Wuyi Gong Village (= Shanqian , ca. 10 km S Chong’an City) ( CWBS 240 ) .

Type material. Holotype Ƌ ( CASS): “ China: Fujian, Chong'an \ Wuyi Shan , 1 km W Wuyi Gong \ 250 m, 15.̄ 18.1.1997 \ leg. H. Schönmann ( CWBS 240 )” . Paratypes: CHINA: Fujian: 117 exs. ( NMW): same sampling data; 11 exs. ( NMW): CWBS 248 ; 5 exs. ( NMW): CWBS 243 ; 1 Ƌ ( NMW): CWBS 241 ; Zheijang : 1 ♀ ( NMW): CWBS 417 .

Differential diagnosis. This species belongs to the group of species with four rows of elytral systematic punctures, absence of clypeal microsculpture, unicolored maxillary palpomeres, and wide-stretched metafemoral pubescence, together with A. chinensis , A. fasciatus , A. fikaceki , A. longipenis , A. masatakai , A. niger , A. splendens , A. wangmiaoi , and A. yunnanensis . It shares eight-segmented antennomeres and presence of apical incision on abdominal ventrite 5 with A. fasciatus , A. yunnanensis and A. longipenis ; small eyes and mesoventral carina with A. fasciatus and A. fujianensis ; similar aedeagus with A. fasciatus . Black elytra also present in A. longipenis . Differs from all these species by absence of yellow clypeal margins and by black pronotum, from A. yunnanensis and A. longipenis also by less wide clypeus and minor length ratio maxillary palpomeres 4:3 (= 1.1, versus 1.3 in A. yunnanensis and A. longipenis ). Similar aedeagus also present in A. decipiens , a species differing by very coarse elytral systematic punctures and reduced metafemoral pubescence.

Description. Total length: 1.8̄ 2.2 mm; elytral width: 0.9̄ 1.1 mm; E.I.: 1.2̄1.3, P.I.: 2.1̄2.2, elytra 2.9̄3.0× as long as pronotum. Habitus broad, evenly oval, strongly convex dorsally.

Coloration. Labrum, clypeus and frons black; maxillary palpi unicolored yellow; pronotum black with narrow yellow margins; elytra, ventrites and legs black.

Head (Fig. 61). Clypeus with distinctly, evenly excised anterior margin; C.I.: 3.8, lateral length ratio clypeus/ eyes = 2.4; microsculpture absent; ground punctures fine, interspaces 2̄3× as wide as punctures; systematic punctures distinct. Eyes small, not protruding, oblique. Antennae with eight antennomeres. Maxillary palpi (Fig. 78) slender, palpomere 2 slightly curving mesad, 1.1̄1.2× as long as pronotum in midline, as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.1, palpomere 4 slightly asymmetrical. Mentum with fine, evenly distributed punctures.

Thorax. Pronotal ground punctation slightly finer than on head; systematic punctures distinct. Elytral ground punctation slightly stronger than on pronotum; systematic punctures moderately distinct, arranged in four rows, mesal rows with strongly reduced number of punctures, not reaching anterior margin. Mesoventrite with low, narrow, median carina in posterior 2/3, slightly increasing in width posteriad.

Legs (Fig. 111). Pubescence present on proximal 2/3 of femora; hairlines slightly oblique on profemur, straight on meso- and metafemur.

Abdomen. Ventrite 5 weakly scerotized apically, with very shallow apical emargination, 6̄9 µm deep, weakly visible at 100× amplification.

Aedeagus (Fig. 153). Length: 0.30̄ 0.32 mm. Phallobase as long as parameres, about as long as wide; margins abruptly bending towards triangular manubrium; border between pigmented and unpigmented portion of ventral face almost reaching manubrium in midline. Parameres wide at base, narrowing apicad; margins sigmoid; apex distinctly bending mesad, tapering; ventral face shorter than dorsal face at base; basal portion of dorsal face reaching distal third of phallobase. Median lobe narrow, finger-shaped; margins almost parallel-sided; apex bluntly rounded, almost reaching apex of parameres; ventral face slightly shorter than dorsal face; corona in subapical position; basal apophyses moderately long, inclining laterad, extending almost into midlength of phallobase.

Ecology. Collected between 200 and 400 m a.s.l. in sandy streams, also slightly polluted, flowing through forests and agricultural area, and in various kinds of pools.

Distribution. China (Fujian, Zheijang).

Etymology. niger (Lat.) = black. The name refers to the entirely black surface.