Agraphydrus pseudoniger Yang & Jia, 2021

Yang, Zhen-ming, Jia, Fenglong, Jiang, Lu & Guo, Qiang, 2021, Four new species of Agraphydrus Regimbart, 1903 with additional faunastic record from China (Coleoptera, Hydrophilidae, Acidocerinae), Deutsche Entomologische Zeitschrift 68 (1), pp. 189-205 : 189

Agraphydrus pseudoniger Yang & Jia sp. nov. Figs 2A, B ; 5 ; 7C

Type locality.

China, Jiangxi Province, Shangyou County, Guanggushan Nature Reserve.

Material examined.

Holotype: male (SYSU); Jiangxi Province , Shangyou County, Guanggushan Nature Reserve, ca 25°55'11"N, 114°03'04"E, 846m a.s.l., 21.vi.2015, Fenglong Jia, Yudan Tang leg. Paratypes: (47exs., IZCAS, SYSU): 21 exs., same data as holotype; 3 exs., Jiangxi Province , Suichuan County, Nanfengmian Nature Reserve, 816m a.s.l., 26°17'04"N, 114°03'52"E, 18.vi.2015, Fenglong Jia, Yudan Tang leg ; 3 exs., Guangdong Province , Dadongshan Nature Reserve, 19-22.vi.2013, Fenglong Jia leg ; 24 exs., Guangdong Province , Nanling, Dadongshan, 22-26.vi.2009, Fenglong Jia leg ; 5 exs, Guangdong Province , Lianzhou City, Dadongshan, 23.ix.2008, Yun Wang leg.

Diagnosis.

This species is distinguished from other species of Agraphydrus by the following combination of characters: labrum, clypeus and frons black; without preocular patches; maxillary palpi with apical palpomere slightly longer than penultimate, palpomere 4 without apical infuscation; clypeus without microsculpture, antennae with eight antennomeres; elytra with four rows of systematic punctures; meso- and metafemora pubescent in about basal 2/3; aedeagus with apex of the parameres distinct bending mesally, corona large, located at subapical position.

Description.

Form and color. Total length:1.9-2.3 mm; elytral width:1.0-1.2 mm; E.I.:1.1-1.2, P.I.:2.1-2.3, elytra 2.5-3 × as long as pronotum. Body oblong oval, distinct convex dorsally. Labrum, clypeus and frons black, preocular patches absent; maxillary palpi unicolored yellow; pronotum black with reddish-brown margin; elytral black; ventrites black; femora and tibia dark reddish-brown, tarsus yellow.

Head. Labrum with dense, fine punctures and several coarse punctures. Clypeus (Fig. 5A ) with angularly deep excised anterior margin and small median notch (Fig. 5B ), without microsculpture, with very sparse ground punctures, coarser than that on the labrum, interspaces 1-3 × as large as punctures. Systematic punctures distinct. Ground punctures on the frons as on the clypeus, systematic punctures distinct. Eyes small, not protruding. Antennae (Fig. 5C ) with eight antennomeres. Maxillary palpi (Fig. 5D ) 1.0-1.1 × as long as pronotum in midline, 0.9-1.0 × as long as maximum width of clypeus; length ratio palpomere 4:3 =1.0-1.3, palpomere 4 asymmetrical. Mentum (Fig. 5E ) with fine and sparse punctures on the lateral portions, without microsculpture.

Thorax. Pronotum ca. 1.10-1.25 × as wide as long, pronotal ground punctures sparse, as on frons, interspaces 1-3 × as large as punctures, surface between ground punctures with microsculpture, systematic punctures distinct, located in the anterior and lateral middle position of the clypeus, each with a long seta on the middle. Elytral ground puncture slightly larger than that on head and pronotum, interspaces 1-2 × as large as punctures, surface between ground punctures as on the pronotum; with four distinct rows of systematic punctures, mesal rows reaching anterior margin. Prosternum slightly convex, without median carina. Mesoventrite (Fig. 5F ) with narrow, needle-like and strong median carina, extending to middle of mesofemora. Metaventrite moderately convex mesally, with small glabrous area posteromedially.

Legs. Pubescence present on proximal 2/3 of femora (Fig. 5H, I, J ), hairline oblique on pro- and mesofemora, straight on metafemora.

Abdomen. Ventrite 5 (Fig. 5G ) round, without apical emargination, with a row of strong setae.

Aedeagus (Fig. 7C ). Length: 0.31mm. Phallobase about as long as parameres, manubrium wide and triangular. Base of parameres wide, slightly narrowing apicad, apical 1/3 strongly narrowed, apex blunt, moderately bending mesad, lateral margin straight at basal 2/3, cambered in apical 1/3, basal protrusion extending into about half of phallobase. Median lobe slender, shaped like an index finger, margin cambered; apex bluntly rounded, slightly shorter than parameres, corona moderately larger, located at subapical position; basal apophyses long, reaching to half of phallobase.

Etymology.

Specific name derived from Latin “pseudo”, false, and " Agraphydrus niger ", black, refers to the similarity with Agraphydrus niger Komarek & Hebauer, 2018.

Distribution.

CHINA (Jiangxi, Guangdong).

Remarks.

This species shares four rows of distinct systematic punctures, absence of clypeal microsculpture, unicolorous maxillary palpomeres, antennae with eight antennomeres with A. fasciatus Komarek & Hebauer, A. niger Komarek & Hebauer, A. yunnanensis Komarek & Hebauer and A. longipenis Komarek & Hebauer. It differs from A. yunnanensis and A. longipenis by eyes small, mesoventrite carinate ( A. yunnanensis and A. longipenis without mesoventral carina), parameres moderately curved inwards subapically, median lobe with corona located at subapical position (apex of parameres not curved inwards, median lobe with corona located at base in A. yunnanensis and A. longipenis ). Shares small eyes, mesoventral carina with A. fasciatus , A. niger and A. fujianensis Komarek & Hebauer, similar aedeagus with A. fasciatus , A. niger and A. politus Komarek & Hebauer, differs from A. fujianensis by abdominal ventrite 5 with apical emargination, coloration of pronotum and elytra (dark yellowish to rufous brown in A. fujianensis , black in A. pseudoniger ), parameres moderately curved inwards subapically and corona of median lobe locating at subapical position (apex of parameres not curved inwards, median lobe with corona basally in A. fujianensis ); from A. politus by small size, with four rows of punctures (ten in A. politus ), phallobase about as long as parameres and apex of parameres moderately curved inwards (phallobase slightly longer than the parameres, parameres strongly curved inwards subapically in A. politus ); from A. fasciatus by clypeus without preocular patches, pronotum and elytra black and parameres slightly longer than median lobe (parameres about 2x as wide as median lobe in A. fasciatus ); from A. niger by clypeus with a deep excision anteriorly and small median notch and mesal rows of systematic punctures reaching anterior margin.

Figures

Figure 2. Habitus: A, B. Agraphydrus pseudoniger sp. nov. C, D. Agraphydrus sabulosus sp. nov.

Figure 5. Agraphydrus pseudoniger sp. nov.: A. Clypeus; B. Clypeus; C. Antennae; D. Maxillary palpi; E. Mentum; F. Mesoventrite; G. Ventrite 5; H. Profemora; I. Mesofemora; J. Metafemora.

Figure 7. Aedeagi: A. Agraphydrus dapengensis sp. nov.; B. Agraphydrus komareki sp. nov.; C. Agraphydrus pseudoniger sp. nov.; D. Agraphydrus sabulosus sp. nov.