Lasconotus niponius ( Lewis, 1879 )

Aoki, Jun-ichi, 2018, Japanese Species of the Genus Lasconotus (Coleoptera: Zopheridae: Colydiinae), with Description of a New Species from Ishigaki-jima Island, the Ryukyu Islands, Species Diversity 23 (1), pp. 69-74 : 70

Lasconotus niponius ( Lewis, 1879)

( Figs 1 and 5 )

Xuthia niponia Lewis, 1879: 462 .

Bitoma niponica: Nakane 1963: 218 , pl. 109, fig. 18.

Bitoma niponia: Narukawa 2000: 1 , pl. 1, fig. 1.

Lasconotus niponius: Ślipiński and Schuh 2008: 83 ; Aoki 2011: 77, figs 1, 2.

Lasconotus sp.: Aoki 2009a: 73, fig. 32A.

Material examined. 1 ex . (JAC-1), Isoyama Beach , Suzuka City, Mie Prefecture, Japan, 27 May 2010, J . Aoki leg . 1 ex. (JAC-2), the same place to JAC-1, 14 June 2008, N . Narukawa leg . 1 ex . (JAC-3), Shimin-no-mori, Kami-Yukawa-cho, Hakodate City , Hokkaido, Japan, 5 October 2015, K . Nagoshi leg . 1 ex. ♂ (JAC-4, dissected and mounted on slides), same place to JAC-1, 27 May 2010, J . Aoki leg .

Diagnosis. Body reddish or yellowish brawn, 1.90– 2.40 mm in length; pronotum length 0.54–0.57 mm; pronotum width 0.55–0.60 mm; elytral length 1.40–1.53 mm; elytral width 0.60–0.63 mm; PW/PL 1.02–1.07; EW/PW 1.03– 1.05; EL/EW 2.30–2.43; EL/PL 2.30–2.68. Terminal club of antenna consists of three larger segments, but ninth segment smaller than terminal two ones; third segment longer than fourth one ( Fig. 1 ). Anterior angles of pronotum rounded; four conspicuous longitudinal carinae on pronotum; elytral ridges rather weak, ridges 3 and 4 joined together before reaching elytral edge. Sculpture on metasternum developed in lateral parts, but vanished in median part; sculpture on ventrites amoeba-like, irregularly connecting here and there ( Fig. 5 ).

Variation. The specimens collected in Hokkaido tend to show two-color body, black (head and prothorax) and reddish (elytra) whereas the body color of specimens from the southern Japan is wholly brawn (somewhat darker on head and thorax than on elytra) ( Aoki 2011). Except the body color, no differences are found between the Hokkaido group and the southern Japan group. Considering the isolated distribution ( Fig. 12 ) of the two groups, they could represent different subspecies, but the only difference is body color with no taxonomical value.

Distribution. Japan: Hokkaido, Honshu (southwestern half), Shikoku and Kyushu.

Figures

Figs 1–4. Antennae (right side) of the four Japanese species of Lasconotus.—1, L. niponius (Lewis, 1879) (JAC-1); 2, L. okadai Aoki, 2011 (JAC-8); 3, L. sculpturatus (Sharp, 1885) (JAC-11); 4, L. akitai sp. nov. (paratype, NSMT-I-C 200239). Scale bars: 0.1mm.

Figs 5–8. Anterior part of ventrites of the four Japanese species of Lasconotus.—5, L. niponius (Lewis, 1879) (JAC-1); 6, L. okadai Aoki, 2011 (JAC-9); 7, L. sculpturatus (Sharp, 1885) (JAC-11); 8, L. akitai sp. nov. (paratype, NSMT-I-C 200239). Scale bars: 0.1mm.

Fig. 12. Distribution map of the four Japanese species of Lasconotus based on the collection data in Nakane (1963), Sasaji (1985), Narukawa (2000), and Aoki (2009a, b, 2011, 2012, 2013a, b).