Fanjingshan water penny beetle (Mataeopsephus fanjingshanus) and Ming-zhi zhao water penny beetle (Mataeopsephus zhaomingzhiis)

NEWS - Fanjingshan water penny beetle (Mataeopsephus fanjingshanus sp. nov.) and Ming-zhi zhao water penny beetle (Mataeopsephus zhaomingzhiis sp. nov.) collected using light traps from Guizhou Province, China.

Psephenidae also known as water beetles include 300 species grouped into 5 subfamilies. Psephenid beetles are known in all zoogeographic regions and have high biodiversity in the Oriental Region.

Larvae are fully aquatic, many of which have very flattened bodies to adapt to living in fast-flowing, clean water by feeding on algae covering rock surfaces. Adults with reduced mouthparts and short-lived can be found on vegetation or in litter and near rivers.

Mataeopsephus Waterhouse 1876 includes 12 valid species and all are distributed in East and South Asia with 7 species recorded in China. The researchers added 2 new species collected using light traps.

M. fanjingshanus has a distribution in Guizhou Province. All adults were collected with light traps at Fanjingshan Nature Reserve. The location of the light trap is near the Heiwan River. Specific epithets refer to the type location. Chinese common name: 梵净山硕扁泥甲

Male body oval and flat, dark brown to black, with clypeus, base of antenna, maxillary palpus, labial palpus, femurs (except apical part), tibiae and lateral margin of elytra reddish brown. Surface densely covered with short setae.

Head: Short and transverse, surface densely covered with small punctures, each of them bearing a short seta. Eyes large and distinctly prominent, inner sides with a row of long setae which are much longer than the setae on other parts of the head. Clypeus well developed and distinctly upturned, anterior margin of clypeus straight, anterolateral angles rounded.

Antenna filiform, much longer than half length of elytra, with 11 antennomeres, surface of antennomeres densely covered with short setae; scape columnar, elongate, widest near middle; pedicel longer than wide, about half length of pedicel, expanded near apex; antennomeres III–XI flattened, antennomeres III longest, weakly expanded near apical 1/4; antennomeres IV–X longer than wide, gradually shorter; antennomere XI long-oval, with aculeated apex; relative lengths of antennomeres I–XI: 1.00: 0.57: 1.37: 1.03: 0.97: 0.85: 0.76: 0.69: 0.59: 0.55: 0.64.

Maxillary palpus 4-segmented, segment I shortest, slightly longer than wide; segment II elongate, longest among all segments, widest near apex; segment III longer than half the length of segment II; segment IV longer than segment III, long-oval.

Labial palpus 3-segmented, segments I and II short, slightly longer than wide; segment III elongate, about as long as the sum of segments I and II, apical half distinctly curved.

Pronotum transverse, surface densely covered with short setae with a narrow and longitudinal hairless area located at base of middle of pronotum, about 1/3 length of pronotum; anterior and lateral margins finely curved, posterior margin bisinuate.

Anterior angles nude, posterior angles acutangular with rounded apex. Prosternum with surface finely covered with setae in different lengths, setae on disc distinctly longer than on other parts; prosternal process narrowed at middle, with apical half fusiform.

Scutellum triangular with rounded angles, surface sparsely covered with very short setae. Elytra finely punctate, densely covered with short setae, surface with several shallow longitudinal stripes. Disc of prosternum distinctly concaved, hairless, other parts covered with setae in different lengths, posterior margin weakly curved to inward side.

Legs simple, femora strong and expanded, bicolored, areas near apex dark brown, other parts reddish brown, surface densely covered with very short setae; surface of tibiae hairless, covered with sparse and small punctures, protibiae distinctly curved at middle, meso- and metatibiae curved at basal 1/3. Tarsi simple, tarsomere V about as long as the sum of tarsomeres I–IV, tarsal claws simple.

Abdomen with five visible sternites, ventrite VI partially visible sometimes. Surface of abdominal ventrites covered with dense short setae. Posterior margin of ventrite V strongly curved anteriorly. Abdominal sternite IX long-oval, posterior margin with a pair of clusters of long setae, rounded at middle.

Aedeagus fusiform in general, symmetrical. Median lobe finger-like in ventral view, with rounded apex, shorter than parameres. Parameres longer than 1/3 length of basal piece, apical part of parameres triangular with rounded apex, surface finely covered with small punctures.

Measurements: BL: 6.37–7.59 mm; HL: 0.62–0.73 mm; HW: 1.29–1.46 mm; PL: 1.39–1.67 mm, PW: 2.39–3.07 mm; EL: 4.36–5.19 mm, EW: 3.21–3.88 mm.

Females generally like males, usually larger. Antenna subserrate, distinctly shorter than male, about half length of elytra; antennomeres III–X distinctly expanded, antennomeres IV–X subserrate; antennomere XI long-oval, apex with a very small projection; relative lengths of antennomeres I–XI: 1.00: 0.52: 1.09: 0.87: 0.78: 0.71: 0.65: 0.59: 0.54: 0.45: 0.63.

Apex of prosternal process with apical rounded than male. Prosternum with posterior margin weakly curved to posteriorly side. Maxillary palpus distinctly short than male; segment III of labial palpus only weakly curved. Measurements: BL: 7.25–8.89 mm; HL: 0.64–0.77 mm; HW: 1.42–1.53 mm; PL: 1.63–1.82 mm, PW: 2.94–3.46 mm; EL: 4.98–6.30 mm, EW: 3.56–4.49 mm.

M. zhaomingzhiis distributed in Guizhou Province. All adults were collected by light traps in Leigongshan Nature Reserve. The species is named in honor of Mr. Ming-zhi zhao who collected the new species and donated it for research. Chinese common name: 赵氏硕扁泥甲

Male body oval and flat, pronotum dark brown to black, with elytra clypeus, antennae, maxillary palpus, labial palpus and legs brown. Surface densely covered with short setae. Head: Short and transverse, surface finely covered with large punctures, each of them bearing a short seta.

Eyes large and distinctly prominent, inner sides with a row of setae which are slightly longer than the setae on other parts of the head. Clypeus well developed and distinctly upturned, anterior margin of clypeus straight, anterolateral angles rounded.

Antenna filiform, slightly shorter than length of elytra, with 11 antennomeres, surface of antennomeres densely covered with short setae; scape columnar, elongate, expanded at middle; pedicel longer than wide, about half length of pedicel, expanded near apex; antennomere III longest, widest at apex; antennomeres IV–X flattened, longer than wide, gradually shorter; antennomere XI long-oval, with aculeated apex; relative lengths of antennomeres I–XI: 1.00: 0.56: 1.25: 1.15: 1.04: 0.89: 0.87: 0.79: 0.70: 0.60: 0.70.

Maxillary palpus 4-segmented, segment I shortest, slightly longer than wide; segment II elongate, longest among all segments, widest near apex; segment III about as long as 2/3 length of segment II; segment IV longer than segment III, long-oval.

Labial palpus 3-segmented, segments I and II short, segment I transverse, segment II about as long as wide; segment III elongate, about as long as the sum of segments I and II, apical half distinctly curved.

Pronotum transverse, surface densely covered with large punctures and short setae, a narrow and longitudinal hairless area located at base of middle of pronotum, about 1/3 length of pronotum; anterior and lateral margins finely curved, posterior margin bisinuate. Anterior angles nude, posterior angles obtuse with rounded apex.

Prosternum with surface finely covered with setae in different lengths, setae on disc distinctly longer than on other parts; prosternal process narrowed at middle, with apical half fusiform.

Scutellum hemicycle, surface sparsely covered with very short setae. Elytra finely punctate, densely covered with short setae, surface with several shallow longitudinal stripes. Prosternum with disc hairless and distinctly concaved, other parts covered with setae in different lengths, posterior margin distinctly curved to inward side.

Legs simple, femora strong and expanded, areas near apex darker, other parts reddish brown, surface densely covered with very short setae; surface of tibiae hairless, protibiae weakly curved at middle. Tarsi simple, tarsomere V distinctly longer than sum of tarsomeres I–IV, tarsal claws simple.

Abdomen with five visible sternites, ventrite VI partially visible sometimes. Surface of abdominal ventricles densely covered with short setae. Posterior margin of ventrite V strongly curved anteriorly. Abdominal sternite IX long-oval, posterior margin with a pair of clusters of long setae, weakly curved anteriorly at middle. Aedeagus long-fusiform in general, symmetrical.

Median lobe finger-like in ventral view, with rounded apex, distinctly longer than parameres. Parameres elongate, about as long as 1/3 length of basal piece, surface finely covered with small punctures.

Measurements: BL: 5.88 mm; HL: 0.57mm; HW: 1.19mm; PL: 1.31mm, PW: 2.17mm; EL: 4.00 mm, EW: 2.85 mm.

Females generally like males, usually larger. Antenna subserrate, distinctly shorter than male, shorter than half length of elytra; antennomeres IV–X distinctly expanded, subserrate; antennomere XI long-oval, apex rounded; relative lengths of antennomeres I–XI: 1.00: 0.50: 0.90: 0.79: 0.65: 0.58: 0.55: 0.51: 0.48: 0.40: 0.45.

Apex of prosternal process with apical rounder than male. Prosternum with posterior margin weakly curved to posterior side. Maxillary palpus distinctly shorter than male; segment III of labial palpus weakly curved. Measurements: BL: 7.30–7.32 mm; HL: 0.63–0.71 mm; HW: 1.38–1.41 mm; PL: 1.37–1.41 mm, PW: 2.85–2.91 mm; EL: 5.20–5.30 mm, EW: 3.77–3.95 mm.

Original research

Ri-Xin Jiang & Xiang-Sheng Chen (2024). Two new species of the genus Mataeopsephus Waterhouse, 1876 (Coleoptera: Psephenidae) from Guizhou, China. Zootaxa 5528 (1): 106-117, DOI:10.11646/zootaxa.5528.1.9

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