Agraphydrus longipalpus ( Jia, 1998 )

Komarek, Albrecht & Hebauer, Franz, 2018, Taxonomic revision of Agraphydrus Régimbart, 1903 I. China and Taiwan (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4452 (1), pp. 1-101 : 46-48

Agraphydrus longipalpus ( Jia, 1998)

(Figs. 30, 58, 108, 150)

Pseudopelthydrus longipalpus Jia 1998: 229 .

Agraphydrus longipalpis ( Jia, 1998) ; Komarek 2003: 384 (incorrect subsequent spelling).

Agraphydrus longipalpus ( Jia, 1998) ; Komarek 2003: 384.

Type locality. China, Hainan Prov., Jianfengling National Forest Park.

Type material (not examined): Holotype Ƌ ( ZUG): China, Hainan Prov., Jianfengling , 11.IV.1983, leg. Zhihe Huang . Paratypes: 2 ♂♂, 3 ♀♀ ( ZUG): same locality data.

Additional material examined. CHINA: Hainan: 2 ♂♂, 2 EE ( NMW): CWBS 189 ; 3 ♂♂, 5 E (NMW): CWBS 194; 1 ♂ (NMW): CWBS 199; 22 exs. (NMW): CWBS 204; 38 exs. ( NMP): Hainan, Limushan Mts. , 19°9.1̄9.2'N 109°45̄46'E, 550̄ 750 m a.s.l., “seepages with thin algae layer and nearly bare wet rocks without distinct algae along most remote end of road”, 5.V.2011 , leg. M. Fikáček & Zhao lgt. “MF18”; 106 exs. ( NMP, NMW): same sampling data, but “sifting of moist to wet leaf litter along the streams in secondary forests with bamboo”; 29 exs. ( NMP, NMW): same sampling data, but “small streamlet in secondary forest with bamboo, among gravel and stones at the small pools and on a wet stone covered with decaying leaves”; 2 exs. ( NMP): same sampling data, but “exposed pools along the road, partly connected to the stream, sparsely to densely overgrown by grass”; 2 exs. ( NMP): same sampling data, but “rotting banana trunks at the stream in secondary forest”; 26 exs. ( NMP, NMW): Limushan Mts. , mountains above forest admin. centre, 19°10.5̄10.9′N 109°44̄45′E, 650̄ 900 m a.s.l., “wet horizontal rock in streambed with thin water film and lots of fallen leaves, only partly exposed”, 6.V.2011 , leg. Fikáček “MF19”; 11 exs. ( NMP): Bawangling Mts., Yajia , 5 km SE of Baotie, 19°5.29'N 109°7.41'E, 415 m a.s.l., “stony river and drying-up stream in lowland forest, side pools among gravel, algae at rock banks and on wet rocks”, 7.V.2011 , leg. M. Fikáček & Zhao “MF20”; 1 ♂ ( NMP): same sampling data, but “along the stony river in a lowland forest, low water level, side pools and algae at rock banks”; 12 exs. ( NMP): Cainanyang , 5 km SE of Baotie, 340 m a.s.l., 19°5.89'N 109°6.61'E, “small stony river in lowland forest, at water surface and among gravel and stones at side of river”, 8.V.2011 , leg. M. Fikáček “MF22”.

Differential diagnosis. This species belongs to the group of species with anteriorly abbreviated mesal rows of elytral systematic punctures, absence of clypeal microsculpture, and reduced metafemoral pubescence, together with A. reductus , A. calvus , A. indicus , and A. geminus . It shares absence of apical infuscation on maxillary palpomere 4 with A. reductus and A. geminus , and comparatively large eyes with A. indicus . It differs from all species mentioned by nine-segmented antennae, presence of emargination on abdominal ventrite 5, features of aedeagus (parameres slender, phallobase shorter than parameres, corona in basal position) and largest size (other species mentioned less than 2.2 mm long, but very large individuals of A. geminus with 2.3 mm in length).

Description. Total length: 2.2̄3.0 mm, elytral width: 1.2̄ 1.7 mm; E.I.: 1.2, P.I.: 2.3̄2.5, elytra 2.8̄3.2× as long as pronotum. Habitus broad, evenly oval, moderately convex dorsally.

Coloration. Labrum rufous anteriorly, black posteriorly; clypeus unicolored yellow, or dark brown to black in mesal portion, with undefined, wide, yellow lateral preocular area; frons black; maxillary palpi unicolored yellow; pronotum dark brown or black mesally with yellow lateral margins; elytra dark brown or black with lighter brown lateral and posterior portion in most cases; ventrites black; legs dark brown to black.

Head (Fig. 58). Clypeus with distinctly, evenly excised anterior margin; C.I.: 4.4, lateral length ratio clypeus/ eyes = 1.5; microsculpture absent; ground punctures fine, interspaces 3× as wide as punctures or wider; systematic punctures indistinct. Eyes large, but not protruding, slightly oblong. Antennae with nine antennomeres. Maxillary palpi moderately stout, 0.8̄1.0× as long as pronotum in midline, 0.9× as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.1̄1.3, palpomere 4 biconvex, almost symmetrical. Mentum with very fine, widely spaced punctures.

Thorax. Pronotal ground punctation as on head; systematic punctures moderately distinct. Elytral ground punctation fine, stronger than on head and pronotum, interspaces about 1̄2× as wide as punctures; systematic punctures moderately distinct, arranged in four rows, mesal rows with strongly reduced number of punctures, not reaching anterior margin. Mesoventrite with mesal bulge, gently rising from anterior margin and abruptly sloping between mesocoxae, with a very low crescentic mesal elevation.

Legs (Fig. 108). Pubescence present on proximal 2/3 of pro- and mesofemur with straight hairlines; restricted to a narrow anterior strip and a small proximal area on metafemur.

Abdomen. Ventrite 5 with very shallow apical emargination.

Aedeagus (Fig. 150). Length: 0.37̄0.45. Phallobase shorter than parameres, abruptly bending towards distinctly delimited, moderately wide manubrium; border between pigmented and unpigmented portion of ventral face reaching midlength in midline. Parameres widest in midlength; mesal margins strongly sigmoid, lateral margins weakly curved; apex moderately wide, bluntly rounded, not inflated, asymmetrical, very weakly inclining mesad; basal portion almost reaching midlength of phallobase mesally. Median lobe wide basally, margins evenly converging towards narrow, spatulate distal half; apex not reaching apex of parameres; crescentic, sclerotized structure present in proximal half; corona large, in basal position; basal apophyses short, widely separated, inclining laterad, extending to distal fourth of phallobase.

Remarks. Description and figures in Jia (1998) exclude doubts about the diagnostic characters of the species, even though the type material could not be examined.

Ecology. Collected between 150 and 900 m a.s.l.; in streams flowing through primary and secondary forests; on wet rock with thin water film and accumulated leaves; in side pools among gravel, big boulders, and algae.

Distribution. China (Hainan).

Agraphydrus longipenis sp. n.

(Figs. 31, 59, 76, 109, 151)

Type locality. Laos, Luang Nam Tha Prov., Luang Nam Tha [City] environment.

Type material. Holotype Ƌ ( NMW): “N̄ LAOS \ Luang Namtha env. \ 800̄ 1200 m \ May 1997 [collector not mentioned]”. Paratypes : CHINA: Yünnan: 4 exs. ( NMW): CHINA , Yünnan, National Nabanhe Nature Reserve, vicinity of Naban village, 30 km N Jinghong, near small tributary to Naban River , at light, 13.XII.2007, leg. A. Weigel.

Differential diagnosis. This species belongs to the group of species with four rows of elytral systematic punctures, absence of clypeal microsculpture, unicolored maxillary palpomeres, eight-segmented antennae, widestretched metafemoral pubescence, and apical emargination on abdominal ventrite 5, together with A. fasciatus , A. niger and A. yunnanensis . It shares large eyes, similar proportions of clypeus, similar length ratio of maxillary palpomeres, and absence of mesoventral carina with A. yunnanensis , in contrast to A. fasciatus and A. niger . It shares black elytra with A. niger . It differs from A. yunnanensis , a species with similarly shaped parameres, by median lobe (very narrow, with corona in basal position) and absence of preocular patches. It differs from all species of Agraphydrus by features of aedeagus.

Description. Total length: 2.0 mm; elytral width: 1.0 mm; E.I.: 1.3, P.I.: 2.2, elytra 3.0× as long as pronotum. Habitus moderately broad, evenly oval, moderately to strongly convex dorsally.

Coloration. Labrum, clypeus and frons black; clypeus with undefined very narrow rufous lateral margins; maxillary palpi unicolored yellow; pronotum dark brown with narrow, undefined yellow lateral margins, elytra black with undefined brighter lateral and posterior areas; ventrites black; legs dark brown.

Head (Fig. 59). Clypeus with distinctly, evenly excised anterior margin; C.I.: 4.8, lateral length ratio clypeus/ eyes = 1.9; microsculpture absent, except some wrinkles present on antero-lateral angle; ground punctures fine, interspaces 2× as wide as punctures; systematic punctures moderately distinct. Eyes large, but not protruding, slightly oblong. Antennae with eight antennomeres. Maxillary palpi (Fig. 76) slender, as long as pronotum in midline, 0.8× as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.3, palpomere 4 slightly asymmetrical. Mentum, with very fine, widely separated punctures, without microsculpture.

Thorax. Pronotal ground punctation as on head; systematic punctures moderately distinct. Elytral ground punctation as on pronotum; systematic punctures indistinctly visible among ground punctation, arranged in four rows, mesal rows with strongly reduced number of punctures, not reaching anterior margin. Mesoventrite with mesal bulge.

Legs (Fig. 109). Pubescence present on distinctly more than proximal half of femora; hairlines slightly oblique on pro- and mesofemur, straight on metafemur.

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

Aedeagus (Fig. 151). Length: 0.25 mm. Phallobase shorter than parameres, as long as wide or slightly wider than long; margins almost rectangularly bending towards distinctly delimited, narrow manubrium; border between pigmented and unpigmented portion of ventral face indistinct. Parameres very wide in basal half, strongly narrowing towards distal half; margins sigmoid; small, tooth-like projection present in midlength of mesal margin; apex blunt, asymmetrical, not inflated; basal portion reaching basal third of phallobase mesally. Median lobe with very narrow, elongate, pencil-shaped dorsal face, apex almost reaching apex of parameres; ventral face very short, extending to less than halflength of dorsal face; corona large, in basal position; basal apophyses long, widely separated, forceps-like, extending to distal third of phallobase.

Etymology. longus (Lat.) = long. The name refers to the elongate median lobe of the aedeagus.

Ecology. Collected next to a small stream and to a larger river; at light.

Distribution. China (Yünnan), Laos.