Leiodes fracta (Seidlitz, 1875)

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 : 109-112

24. Leiodes fracta (Seidlitz, 1875)

Japanese name: Takei-ô-tamakinokomushi ( Figs. 72–74 )

Anisotoma fracta Seidlitz, 1875: 209 .

Liodes fracta: REITTER (1885) : 106.

Leiodes fracta: HATCH (1929) : 19 (as aberration of Leiodes rhaetica ); DAFFNER (1983): 77 (redescription); PERREAU (2004): 196 (catalogue).

Leiodes takeii Nakane, 1963: 40 ; DAFFNER (1983): 77 (synonymized with L. fracta ).

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

Type locality. Estonia.

Type material examined. Anisotoma fracta : not examined for this study.

Leiodes takeii : JAPAN: HONSHU: HOLOTYPE: ♂, Gunma Pref. Numata , 20.xi.1952, T. Takei leg. ( HUMS).

Additional specimens examined. JAPAN: HONSHU: 1 ♀, Miyagi Pref., Tôgatta , 15.ix.1951, without collector ( EUMJ) ; 1 ♂, same locality, 8.x.1951 ( EUMJ) . SWEDEN: 1 ♂, 1 ♀, Helsingland , without additional data ( FUFJ) .

Published records from Japan (not examined): 1 spec., HONSHU: Nagano Pref., Kamikôchi ( NMPC) ( DAFFNER 1983).

Diagnosis. Coloration. Dorsum usually unicolor, brownish; antennomeres 1 and apical 2/5 of antennomere 11 light brown; antennomeres 2–6 and 8 brown; remaining antennomeres dark brown.

Body 3.5–6.0 mm long, ca. 1.7× as long as wide ( Fig. 72A ); head densely and minutely punctate, bearing some large punctures ( Fig. 72A ); antennomeres 1–3 each longer than wide; antennomere 11 about as long as wide; remaining antennomeres each wider than long; antennomere 11 robust and clearly narrower than 10 ( Fig. 72C ). Pronotum simply and very feebly curved at posterior margin, densely and minutely punctate ( Fig. 72A ). Elytra not transversely strigose; each elytron with nine rows of punctures, bearing small number of large punctures and densely arranged very fine punctures between rows ( Fig. 72D ); row 9 invisible in dorsal view, almost straight, subhumeral row absent ( Fig. 72B ); rows composed of punctures larger and deeper than those on pronotum ( Fig. 72A ); sutural stria fine, reaching from apex to ca. apical half of the elytral length. Metathoracic wings fully developed. Mesoventrite without distinct excavation between median carina and transverse carina ( Fig. 72E ); median carina of mesoventrite low ( Fig. 72E ); metaventrite without sexual dimorphism. Legs showing distinct sexual dimorphism on protarsi, mesotarsi, metafemora, and metatibiae; protibiae gradually widening from base towards apex at internal margins ( Figs. 73F, 73G ); metafemur with large dorsal projection posteroapically, apex of projection pointed ( Figs. 73H, 73I ).

Male. Tarsomeres 2–4 of protarsi and mesotarsi expanded ( Fig. 73A ); metafemora triangularly protuberant at about midlength of posterior margins ( Fig. 73C, 73D ); metatibiae relatively slender, distinctly and complexly curved ( Figs. 73C, 73D ), bearing crenellated tiny spines at internal margins ( Figs. 73C, 73D ); abdominal sternite 8 moderately curved ( Fig. 74C ); aedeagus as shown in Figs. 74A, 74B .

Female. Protarsi and mesotarsi slender ( Fig. 73B ); metafemora weakly curved at posterior margins ( Fig. 73E ); metatibiae relatively robust, weakly sinuate at internal margins, without crenellated tiny spines ( Fig. 73E ); abdominal sternite 8 with a spiculum ventrale at central point of anterior margin ( Fig. 74D ); coxites and stylus as shown in Fig. 74E .

Morphological variability. Two male specimens examined for this study show the morphological variation of the metatibiae. Figs. 73C and 74D were drawn based on specimens whose body lengths are 5.8 mm and 4.8 mm, respectively. It is possible that larger males have relatively more distinct secondary sexual characters on the metatibiae.

Differential diagnosis. Leiodes fracta is similar to L. lucens ( Fairmaire, 1855) in having a large body but can be distinguished from it by having the mesoventrite without a distinct excavation between the median carina and transverse carina ( Fig. 72E ). In contrast, L. lucens has the mesoventrite with one distinct excavation ( Fig. 77E ).

Note. In Japan, Leiodes fracta (Seidlitz, 1875) is a very rare species. Only four specimens have been collected until now (see above).

I have reexamined the holotype of L. takeii and compared them with the specimens from Europe. Based on this comparison, I may confirm the synonymy of the latter species with L. fracta proposed by DAFFNER (1983).

Distribution. Europe, Russia (European Russia, Siberia, Russian Far East) ( DAFFNER 1983), and Japan (Honshu).

Figures

Fig. 72. Leiodes fracta (Seidlitz, 1875). A – body, dorsal view; B – ditto, lateral view; C – antenna; D – elytral punctures; E – mesoventrite, lateral view. Scale I: 1 mm for A and B; II: 1 mm for C; III: 0.5 mm for E.

Fig. 73. Leiodes fracta (Seidlitz, 1875). A – male fore leg, ventral view; B – female fore leg, ventral view; C and D – male hind legs, ventral view; E – female hind leg, ventral view; F – male protibia, dorsal view; G – female protibia, dorsal view; H – male metafemur, dorsal view; I – female metafemur, dorsal view. Scale I: 1 mm for C; II: 1 mm for A, B, D, and E; III: 0.5 mm for F and G; IV: 0.5 mm for H and I.

Fig. 74. Leiodes fracta (Seidlitz, 1875). 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: 0.5 mm for C and D; III: 0.2 mm for E.

Fig. 77. Leiodes lucens (Fairmaire, 1855). 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: 0.2 mm for E; IV: 1 mm for F and G.