Agraphydrus dapengensis 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 dapengensis Yang & Jia sp. nov. Figs 1A, B ; 3 ; 7A

Type locality.

China, Guangdong Province, Shenzhen, Dapeng Penisula.

Material examined.

Holotype: male ( SYSU); Guangdong Province , Shenzhen, beside Nan’ao highway; 22°30'32"N, 114°31'24"E, 4.viii.2019, Fenglong Jia, Zuqi Mai leg. Paratypes: (3 exs., IZCAS, SYSU): same data as holotype .

Diagnosis.

This species is distinguished from other species of Agraphydrus by the following combination of characters: labrum, clypeus and frons black; preocular patches indistinct; head without microsculpture; maxillary palpi with apical palpomere about 1.5 × as long as penultimate, palpomere 4 without apical infuscation; antennae with eight antennomeres; elytra with four rows of systematic punctures; mesofemora pubescent in about basal 2/3, pubescence restricted to a narrow anterior margin and posterior strip on metafemora; aedeagus with parameres is about 1.5 × as long as phallobase, corona located in middle position; parameres with cuspidal, hook-like subapical protrusion.

Description.

Form and color. Total length: 1.7-1.9 mm; elytral width: 0.9-1.0 mm; E.I.:1.2-1.3, P.I.:2.19-2.38, elytra ca. 2.8-3.15 × as long as pronotum. Body broad and oval, weakly convex dorsally. Labrum, clypeus and frons black, clypeus with weakly light brown preocular patches laterally, smaller than eyes; maxillary palpi unicolored yellow, pronotum dark brown with moderate wide reddish-brown lateral margin; elytral black with narrow reddish-brown margin; ventrites black; femora and tibiae dark reddish-brown, tarsomeres yellow brown.

Head. Labrum with dense, fine punctures, without microsculpture. Clypeus (Fig. 3A ) with angularly excised anterior margin, without microsculpture, ground punctures as on the labrum, interspaces 2-4 × as large as punctures, systematic punctures distinct; ground punctures on frons as on clypeus, systematic puncture distinct. Eyes large, not protruding. Antennae (Fig. 3B ) with eight antennomeres. Maxillary palp (Fig. 3C ) about as long as pronotum in midline, 0.75-0.84 × as long as maximum width of clypeus; length ratio palpomere 4:3 =1.27-1.31, palpomere 4 asymmetrical. Mentum (Fig. 3D ) with several fine punctures on lateral portions, without microsculpture.

Thorax. Pronotum ca. 2 × as wide as long, pronotal ground punctures as on frons, surface between ground punctures without microsculpture, systematic punctures distinct, forming a row in the anterolateral and located lateral middle position of the clypeus, each with a long seta. Elytral ground punctation as on head and pronotum, surface between ground punctures as on pronotum; with four distinct rows of systematic punctures, mesal rows of systematic punctures reaching anterior margin. Prosternum slightly convex, without carina medially, with a transverse groove. Mesoventrite (Fig. 3E ) with moderate bulge, abruptly declining posteriorly, with horizontal ridge posteriorly. Metaventrite with distinct mesal convexity, bearing a small glabrous area posteromedial part.

Legs. Pubescence present on proximal 2/3 of profemora (Fig. 3G ) with oblique hairline, on about half of mesofemora (Fig. 3H ) with straight hairline, restricted to a narrow anterior strip on the basal half of metafemora (Fig. 3I ).

Abdomen. Ventrite 5 (Fig. 3F ) without apical emargination.

Aedeagus (Fig. 7A ). Length: 0.53mm. Phallobase about 2/3 × as long as the parameres, manubrium wide at base, about third of the width of phallobase, apex handle shape. Parameres wide at the base, margin narrowing apicad; apex obliquely, with cuspidal, hook-like subapical protrusion and with strong constriction in the apical 1/4; middle margin slight sigmoid-shape. Basal protrusion extending into 1/5 of the phallobase. Median lobe wide at the base, strongly narrowing toward apex; apex dentiform, almost as long as the parameres, corona moderately large, located in middle position; basal apophyses long, vertical, barb shape, almost reaching half of phallobase.

Etymology.

This species is named after the type locality, Dapeng Peninsula, Shenzhen, Guangdong Province.

Distribution.

Only known from type locality.

Remark.

This species shares similar dorsal coloration, maxillary palpi unicolorous yellow, mesoventrite with strong mesal bulge and similar aedeagus with A. activus Komarek & Hebauer and A. anhuianus Hebauer, but differs from them by its clypeus without small median notch, antennae with eight antennomeres, pubescence restricted to a narrow anterior strip on the basal half of metafemora, phallobase moderately long and the lateral margin of parameres slightly curved (phallobase short in A. activus and A. anhuianus , the lateral margin of parameres straight in proximal 3/4 in A. activus and lateral margin slightly sinuate in proximal 3/4 in A. anhuianus ). It shares maxillary palpi unicolorous yellow, mesoventrite with distinct mesal bulge and metafemoral pubescence restricted to anterior margin or absent with A. longipalpus (Jia) and A. calvus Komarek & Hebauer, but differs from them by parameres with hook-like subapical protrusion and median lobe with corona located in middle position (parameres without hook-like subapical protrusion, median lobe with corona located in basal position, crescentic sclerotized structure existing in A. longipalpus ; parameres without hook-like subapical protrusion, median lobe with corona situated in distal to midlength, shield-shaped sclerotized structure existing in A. calvus ).

Figures

Figure 1. Habitus: A, B. Agraphydrus dapengensis sp. nov. C, D. Agraphydrus komareki sp. nov.

Figure 3. Agraphydrus dapengensis sp. nov.: A. Clypeus; B. Antennae; C. Maxillary palp; D. Mentum; E. Mesoventrite; F. Ventrite 5; G. Profemora; H. Mesofemora; I. Metafemora.

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