Leiodes obesa ( Schmidt, 1841 )

Hoshina, Hideto, 2012, Review of the tribes Sogdini and Leiodini from Japan and North Chishima Islands. Part II. Genera Hydnobius and Leiodes (Coleoptera: Leiodidae), Acta Entomologica Musei Nationalis Pragae (suppl. 1) 52, pp. 1-168 : 122-126

28. Leiodes obesa ( Schmidt, 1841)

Japanese name: Ezo-ô-tamakinokomushi ( Figs. 82–84 )

Anisotoma obesa Schmidt, 1841: 150 .

Liodes obesa: REITTER (1885) : 99.

Leiodes obesa: HATCH (1929) : 30; DAFFNER (1983): 90 (redescription); COOTER (1996): 255 (key to British species of Leiodes ); ŠVEC (1996): 74 (new to Uzbekistan, Turkmenia, Kirghizia); BOROWIEC & COOTER (1999): 55 (list of Polish species of Leiodes ); PERREAU (2004): 197 (catalogue); PARK & AHN (2007): 41 (list of Korean species of Leiodes ).

Leiodes obesus: LAFER (1989a) : 323 (key to species of Leiodes in Russian Far East).

See HATCH (1929) and DAFFNER (1983) for additional synonymy and references.

Type locality. Germany.

Type material. Not examined.

Additional material examined. JAPAN: HOKKAIDO: 1 ♂, Rausu Town, Shiretoko Pass , 19.–25.vii.1997, S. Hori leg. ( FUFJ) ; 1♀, Rausu Town, Shiretoko , 18.vii.–1.viii.2001, S. Hori leg. ( FUFJ) ; 1 ♂, 1 ♀, Shari Town, Ikushina , 25.vi.2005, T. Katô leg. (they were collected near street lamps) ( FUFJ) ; 1 ♂, Koshimizu Town, Nogami Pass , 27.vii.2005, M. Saitô leg. ( FUFJ) ; 1 ♂, Mts. Daisetsu, Mt. Kurodake , 31.viii.1987, N. Yasuda leg. ( FUFJ) ; 1 ♂, Muka-yama , 10.v.1975, T. Hattori leg. ( FUFJ) . UNITED KINGDOM: 1 ♂, Cassop Vale, Durham , 9.vii.1985, D. Shirt leg. ( FUFJ) . SLOVAKIA: 2 ♀♀, N. Tatry , Kráľova hola , L. Klíma leg. ( FUFJ) .

Diagnosis. Coloration. Dorsum usually unicolor ( Fig. 82C ), rarely bicolored ( Fig. 82D ); head and pronotum usually brownor a little reddish brown or rarely dark brown; elytra brown or reddish brown, rarely with dark brown stripe near elytral suture ( Fig. 82D ); antennae brownish; antennomeres 1–6 and 8 brown, antennomeres 7, 9, 10, and basal 2/3 of antennomere 11 usually dark brown, apical 1/3 of antennomere 11 light brown.

Body 3.0–4.0 mm long, ca. 1.7× as long as wide ( Fig. 82A ); head densely and minutely punctate, bearing some large punctures ( Fig. 82A ); antennomeres 1–4 each longer than wide; antennomeres 5 and 11 each about as long as wide; remaining antennomeres each wider than long; antennomere 11 oval ( Fig. 82E ). Pronotum feebly sinuate at posterior margin and densely and minutely punctate ( Fig. 82A ). Elytra not transversely strigose; each elytron with nine rows of punctures, bearing small number of large punctures and moderate number of very fine punctures between rows ( Fig. 82F ); row 9 invisible in dorsal view, subhumeral row as long as ca. 1/3 of elytral length ( Fig. 82B ); rows composed of punctures larger and deeper than those of pronotum ( Fig. 82A ); sutural stria fine, reaching from apex to ca. apical 2/5 of the elytral length. Metathoracic wings fully developed. Mesoventrite without distinct excavation between median carina and transverse carina ( Fig. 82G ); median carina of mesoventrite low ( Fig. 82G ); metaventrite without sexual dimorphism. Legs showing distinct sexual dimorphism on protarsi, mesotarsi, metafemora, and metatibiae; protibiae showing indistinct sexual dimorphism.

Male. Protibiae distinctly widening from base towards apex at internal margins ( Fig. 83F ); tarsomeres 2–4 of protarsi and mesotarsi expanded ( Fig. 83A ); metafemur with some tiny humps at posterior margin ( Figs. 83C, 83D ), with large dorsal projection posteroapically ( Fig. 83G ); metatibiae distinctly curved ( Figs. 83C, 83D ), often expanded inwards at basal 1/4 of internal margins and with some small robust spines at about midlength of internal margins ( Fig. 83C ), sometimes simply curved at internal margins and without distinct tiny spines ( Fig. 83D ); abdominal sternite 8 strongly curved ( Fig. 84C ); aedeagus as shown in Figs. 84A, 84B .

Female. Protibiae bearing almost parallel-sided margins ( Fig. 83H ); protarsi and mesotarsi slender ( Fig. 83B ); metafemur with a moderately large dorsal projection posteroapically ( Fig. 83I ); metatibiae almost straight ( Fig. 83E ); abdominal sternite 8 with spiculum ventrale at central point of anterior margin ( Fig. 84D ); coxites and stylus as shown in Fig. 84E .

Morphological variability. Males vary morphologically in correlation to the body size. Large males have extremely well developed secondary sexual characters on the metatibiae which are expanded at the basal 1/4 of internal margins and bear some crenellated tiny spines at about the distal half of the internal margins ( Fig. 83C ). In contrast, small males have metatibiae that are simply curved and bearing no tiny spines ( Fig. 83D ). Figs. 83C and 83D are drawn based on specimens with the body size 3.2 mm and 3.6 mm, respectively.

Diffrential diagnosis. Leiodes obesa is similar to L. okawai in having the aedeagus rounded at the apex, but can be distinguished from the latter by having the mesoventrite without distinct excavation ( Fig. 82G ) and the subhumeral row as long as ca. 1/3 of the elytral length ( Fig. 82B ). In contrast, L. okawai has the mesoventrite with a distinct excavation ( Fig. 64E ) and no subhumeral row ( Fig. 64B ).

Distribution. Europe, Russia, Mongolia, Korea ( DAFFNER 1983), and Japan: Hokkaido and South Chishima Islands (Kunashiri Island). New to Hokkaido.

Figures

Fig. 82. Leiodes obesa (Seidlitz, 1841). A – body, dorsal view; B – ditto, lateral view; C and D – dorsal color; E – antenna; F – elytral punctures; G – mesoventrite, lateral view. Scale I: 1 mm for A and B; II: 0.5 mm for E; III: 0.2 mm for G.

Fig. 83. Leiodes obesa (Seidlitz, 1841). A – male fore leg, ventral view; B – female fore leg, ventral view; C – hind leg of male specimen (body size: 3.6 mm), ventral view; D – ditto (body size: 3.2 mm); E – female hind leg, ventral view; F – male protibia, dorsal view; G – male metafemur, dorsal view; H – female protibia, dorsal view; I – female metafemur, dorsal view. Scale I: 0.5 mm for A and B; II: 1 mm for C, D, and E; III: 0.2 mm for F and G; IV: 0.2 mm for H and I.

Fig. 84. Leiodes obesa (Seidlitz, 1841). A – aedeagus, dorsal view; B – ditto, lateral view; C – male abdominal sternite 8; D – female abdominal sternite 8; E – coxite and stylus. Scale I: 0.5 mm for A and B; II: 0.2 mm for C and D; III: 0.1 mm for E.

Fig. 64. Leiodes okawai Nakane, 1963.A – body, dorsal view; B – ditto, lateral view; C – antenna; D – elytral punctures; E – mesoventrite, lateral view; F – male metaventrite; G – female metaventrite. Scale I: 1 mm for A and B; II: 0.5 mm for C; III: 0.5 mm for E; IV: 1 mm for F and G.