Agraphydrus politus Hansen, 1999

Komarek, Albrecht & Hebauer, Franz, 2018, Taxonomic revision of Agraphydrus Régimbart, 1903 I. China and Taiwan (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4452 (1), pp. 1-101 : 51-52

Agraphydrus politus Hansen, 1999

(Figs. 34, 79, 112, 154)

Megagraphydrus politus Hansen 1999: 138 .

Agraphydrus politus ( Hansen, 1999) ; Minoshima Komarek & Ôhara 2015: 24 ff.

Megagraphydrus wangi Hebauer 2000: 17 ; Minoshima et al. 2015: 24 ff.

Type locality. Taiwan, New Taipei City, Wulai.

Type material examined. Megagraphydrus politus . Holotype: Ƌ ( NMW): “ TAIWAN: Taipei \ Wulai 8.9.1993 \ leg. M.L. Jeng | HOLOTYPE \ Megagraphydrus \ politus \ M. Hansen”.

Megagraphydrus wangi . Holotype: Ƌ ( NMW): “ TAIWAN: Taipei Hsien \ Sanhsia 250m \ 24°51'21''N 121°24'33''E \ 16.III.1996 \ leg. L. J. Wang | ♂ | waterfall | HOLOTYPE \ Megagraphydrus \ wangi sp. n. \ des. F. Hebauer”.

Additional material examined: TAIWAN: 1 Ƌ ( NMW): Taiwan, Basianshan National Forest Recreation Area, Heping, 24°11.55′N 121°00.83′E, 920 m a.s.l., wet cement, 6.VI.2010, leg. Y. Minoshima “L140”; 1 ex. ( NMW): Taiwan, Basianshan National Forest Recreation Area, Heping, 24°11.60′N 121°00.76′E, 910 m a.s.l., wet rock, 7.VI.2010, leg. Y. Minoshima “L143”; 2 exs. ( NMW): Taiwan, Temple Taipei, 16.II.2004, C.-F. Lee.

Differential diagnosis. This species belongs to the group of species with coarse elytral punctures arranged in nine to ten rows, together with A. attenuatus , A. insidiator , A. jaechi , A. regularis , and A. siamensis . It shares eightsegmented antennomeres, arrangement of coarse punctures in alternating primary and secondary rows, and reduced metafemoral pubescence with A. insidiator , in contrast to all other species mentioned. Aedeagus very similar to aedeagus of A. insidiator with wide, apically inclining parameres; differs from this species by more numerous, less distant coarse elytral punctures.

Description. Total length: 2.7̄ 3.2 mm; elytral width: 1.4̄ 1.7 mm, E.I.: 1.3, P.I.: 2.3, elytra 3.0× as long as pronotum. Habitus broad, elytra very slightly attenuating apicad, moderately convex dorsally.

Coloration. Labrum, clypeus and frons black, preocular patches absent; maxillary palpi unicolored yellow; pronotum dark brown to black with decreasing intensity of coloration towards yellowish lateral margins; elytra black with narrow, undefined yellowish lateral margins; ventrites black; legs dark rufous.

Head. Clypeus with distinctly, evenly excised anterior margin; C.I.: 4.2, lateral length ratio clypeus/eyes = 2.2; microsculpture absent; ground punctures very fine, interspaces 2̄4× as wide as punctures; systematic punctures distinct. Eyes moderately large, but not protruding, slightly oblong. Antennae with eight antennomeres. Maxillary palpi (Fig. 79) slender, as long as pronotum in midline, as long as maximum width of clypeus; length ratio palpomere 4:3 = 1.1̄1.2, palpomere 4 almost symmetrical. Mentum with very fine to obsolete punctation.

Thorax. Pronotal ground punctation as on head; systematic punctures distinct. Elytral ground punctation as on head and on pronotum; very distinct, numerous, coarse punctures present, arranged in four regular “primary” rows of very narrowly spaced punctures with interspaces usually less wide than puncture, alternating with 4̄5 “secondary” rows of more irregularly arranged punctures with interspaces 2̄3× as large as puncture, lateral rows irregular; numerous coarse punctures present within narrow spaces between rows. Mesoventrite with very strong mesal bulge with M-shaped anterior edge.

Legs (Fig. 112). Pubescence present on more than proximal half on femora with almost straight hairlines.

Abdomen. Ventrite 5 with less than semicircular apical emargination, ca. 20 µm deep.

Aedeagus (Fig. 154). Length: 0.42 mm. Phallobase about as long as parameres, longer than wide; margins abruptly bending towards distinct, moderately long manubrium; borderline between pigmented and unpigmented portion of ventral face reaching proximal fourth in midline. Parameres wide basally, slightly narrowing apicad; margins distinctly sigmoid; apex strongly bending mesad, tapering; basal portion of dorsal face reaching distal third of phallobase; ventral face distinctly shorter than dorsal face. Median lobe moderately wide; lateral margins very slightly sigmoid; apex bluntly rounded, not reaching apex of parameres; corona large, in subapical position; basal apophyses moderately long, inclining laterad, extending almost to halflength of phallobase.

Ecology. Collected between 250 and 920 m a.s.l.; hygropetric.

Distribution. Taiwan.