Leiodes tanakai, Hoshina, 2012

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 : 147-151

35. Leiodes tanakai sp. nov.

Japanese name: Miyama-ô-tamakinokomushi ( Figs. 6, 101–103)

Type locality. Japan, Shikoku, Tokushima Pref., Higashi-iyayama Village, Nagoro, Otome-dani Valley.

Type material. JAPAN: SHIKOKU: HOLOTYPE: 3, Tokushima Pref., Higashi-iyayama Village, Nagoro, Otome-dani Valley , 5–12.viii.2006, K. Tanaka leg. ( FIT) ( MNHAH). PARATYPES, 1 3, Kôchi Pref., forest in Aki (33º36′08″N 134º05′33″E, alt. 550 m), 31.vii.2009, M. Makihara leg. ( MT) ( FUFJ) ; 3 33, 1 ♀, same data as the holotype ( FUFJ) ; 1 3, same data as the former, except for the date, 28.vii.–5.viii.2006 ( FUFJ) ; 1 3, same data as the former, except for the date, 12.–24.viii.2006 ( FUFJ) ; 1 ♀, Tokushima Pref., Kisawa Village, Okuyarito , 23.ix.–5.x.2003, K. Tanaka leg. ( FIT) ( FUFJ) ; 1 3, same data as the former, except for the date, 8.–14.vii.2004 ( FUFJ) ; 1 ♀, same data as the former, except for the date, 14–19.vii.2004 ( FUFJ) ; 1 3, same data as the former, except for the date, 19.–24.vii.2004 ( FUFJ) ; 1 3, Tokushima Pref., Mt. Tsurugii, Minokoshi (alt. 1340 m), 28.vii.–5.viii.2006, K. Tanaka leg. ( FIT) ( FUFJ) ; 1 3, Tokushima Pref., Mima City, Anabuki-chô, Furumiya , Mt. Tsunatsuke-yama ( Alt. 1050 m), 21.–27.viii.2007, K. Tanaka leg. ( FIT) ( FUFJ) ; 1 ♀, Tokushima Pref., Mima City, Koyadaira, Kawakami , Mt. Maruzasa-yama (alt. 1380m), 18–22.vii.2007, K. Tanaka leg.( FIT) ( FUFJ) ; 1 3, 1♀, same data as the former except for the date, 27.vii.–12.viii.2007 ( FUFJ). HONSHU: 1 3, Nara Pref., Tenkawa Village, Mts. Ohmine , 14.ix.1973, K. Harusawa leg. ( FUFJ) ; 1 ♀, Fukui Pref., Ôno City, Heikedaira , 31.viii.1997, S. Inoue leg. ( MT) ( FUFJ) ; 1 3, Fukui Pref., Ikeda Town, Hekosan , 1.viii.1998, S. Inoue leg. ( MT) ( FUFJ) ; 1 3, Ishikawa Pref., Mts. Hakusan, Sarukabe-entei , 22–29.viii.2002, H. Hoshina leg. ( FIT) ( FUFJ) ; 1 3, same data as the former except for the date, 4–14.ix.2002 ( FUFJ) ; 1 ♀, Saitama Pref., Naguri Village, Mt. Arimayama (alt. 1200 m), 17.–24.vii.2004, K. Arai and S. Arai leg. ( FIT) ( FUFJ) ; 1 3, Saitama Pref., Ohtaki Village, Nakatsukawa-keikoku , Oku-Chichibu-rindô (alt. 1300m), 30.vii.–7.viii.2004, K.Arai & S. Arai leg. ( FIT) ( FUFJ) ; 1 3, Miyagi Pref., Sendai City, Mt. Izumigadake, Kuwanuma-rindô , 4.–17.ix.2009, M. Oikawa leg. ( FIT) ( FUFJ) ; 1 ♀, Yamagata Pref., Ôkura Village, Fujitasawa , 17.–25.vi.2006, M.Oikawa leg. ( FUFJ) ; 13, Yamagata Pref., Ôkura Village, Yunodai , 30.viii.–10.ix.2006, M. Oikawa leg. ( FUFJ) ; 1 3, Aomori Pref., Ajigasawa Town, Kôsei Rindô , 28.xi.1995, T. Ozaki leg. ( FUFJ) .

Diagnosis. Body 2.2–3.1 mm long, ca. 1.9× as long as wide. Dorsum brown. Elytra almost straight from base to ca. basal 1/3 of lateral margins. Each elytron with nine distinct rows of punctures, subhumeral row as long as ca. 1/3 of elytral length. Mesoventrite with one distinct excavation between median carina and transverse carina. Median carina of mesoventrite low. Mesotibiae without distinct sexual dimorphism. Metafemora usually bearing some tiny humps at posterior margins. Metatibiae usually distinctly curved inwards and with some small robust spines at internal margins. Parameres distinctly broadening and bearing many tiny spicular projections at apex. Female abdominal sternite 8 with a spiculum ventrale.

Description. Measurements of holotype: Body length 2.8 mm; head 0.42 mm in length and 0.79 mm in width; pronotum 0.90 mm in length and 1.4 mm in width; elytra 1.8 mm in length and 1.6 mm in width.

Coloration. Dorsum shining, almost unicolor, brown; antennomeres 1–6 and 8 brown; apical 2/5 of antennomere 11 light brown; remaining antennomeres brown or dark brown; legs brownish; all tarsi slightly paler than remaining parts; mesoventrite, metaventrite, and abdominal ventrites brown.

Body 2.2–3.1 mm in length, ca. 1.9× as long as wide.

Head ca. 1.8× as wide as long, ca. 0.49× as long as and 0.56× as wide as pronotum, distinctly and densely punctate ( Fig. 101A), often bearing some large punctures ( Fig. 101A); antennomeres 1–3 each longer than wide; antennomeres 4, 5, and 11 each about as long as wide; remaining antennomeres each wider than long; antennomere 11 oval and clearly narrower than 10 ( Fig. 101C); relative lengths of antennomeres 2 to 11 – 3.5: 3.8: 1.7: 1.8: 1.6: 2.9: 1.0: 3.8: 3.8: 5.2.

Pronotum ca. 1.6× as wide as long, ca. 0.48× as long as and 0.90× as wide as elytra, widest at base, simply and very feebly curved at posterior margin, distinctly and densely punctate, punctation similar to that on head ( Fig. 101A).

Scutellum minutely punctate.

Elytra ca. 1.2× as long as wide in dorsal view, almost straight from base to basal 2/5 of lateral margins ( Fig. 101A), not transversely strigose; each elytron with nine rows of punctures, bearing with small number of large punctures and dense fine punctures between rows ( Fig. 101D); row 9 invisible in dorsal view, subhumeral row as long as ca. 1/3 of elytral length ( Fig. 101B); rows composed of punctures larger than those on pronotum ( Fig. 101A); sutural stria fine, reaching from apex to ca. apical 2/3 of the elytral length.

Metathoracic wings fully developed.

Mesoventrite strongly microreticulate, impunctate, almost glabrous, with one distinct excavation between median carina and transverse carina ( Fig. 101E); median carina of mesoventrite low ( Fig. 101E); metaventrite without sexual dimorphism, sparsely, finely pubescent, strongly microreticulate except for almost smooth middle portion.

Legs showing distinct sexual dimorphism on protarsi, mesotarsi, metafemora, and metatibiae; protibiae gradually and very feebly widening from base towards apex ( Figs. 102F, 102G); metafemur with a small dorsal projection posteroapically ( Figs. 102H, 102I).

Male. Tarsomeres 2–4 of protarsi and mesotarsi expanded ( Fig. 102A); metafemora relatively strongly expanded at midlength of posterior margins, usually bearing some tiny humps at posterior margins ( Fig. 102C), sometimes without humps ( Fig. 102D); metatibiae distinctly curved inwards, with some small robust spines at internal margins ( Fig. 102C) or almost stra- ight and without spines at internal margins ( Fig. 102D); abdominal sternite 8 weakly curved ( Fig. 103E); aedeagus slender ( Figs. 103A, 103B); median lobe apically protuberant in dorsal view ( Fig. 103A), moderately curved and pointed apically in lateral view ( Fig. 103B); each paramere broadening and bearing many tiny spicular projections at apex ( Fig. 103D); inner sac as shown in Fig. 103C.

Female. Protarsi and mesotarsi slender ( Fig. 102B); metafemora feebly curved and bearing no tiny humps at posterior margins ( Fig. 102E); metatibiae almost straight, without small robust spines at internal margins ( Fig. 102E); abdominal sternite 8 with spiculum ventrale at central point of anterior margin ( Fig. 103F); coxites and stylus as shown in Fig. 103G.

Morphological variability. Males of L. tanakai show individual variation of the metafemora and metatibiae. These morphological differences are not regional, but are correlated to body size. The secondary sexual characters are not distinctly developed in small males. The male hind leg on Fig. 102D, which resembles that of the female, was drawn from a male specimen whose body length was 2.4 mm. In contrast, the leg showing distinctly secondary sexual characters on Fig. 102C was drawn from a large male specimen (body length 2.8 mm).

Differential diagnosis. Leiodes tanakai sp. nov. is similar to L. iwakirii sp. nov. in the morphology of the median lobe of the aedeagus, but can be distinguished from it by having the parameres of the aedeagus strongly broadened apically ( Fig. 103D). In contrast, L. iwakirii sp. nov. has parameres weakly broadened ( Fig. 76H). Leiodes tanakai sp. nov. also resembles L. irregularis by having a long-oval body, but can be separated from it by the mesoventrite with a distinct excavation between the median carina and transverse carina ( Fig. 101E). In contrast, L. irregularis has the mesoventrite without an excavation ( Fig. 93J).

Etymology. The species is dedicated to Mr. Kôji Tanaka who is a collector of valuable specimens of Leiodes used in this study.

Distribution. Japan: Honshu and Shikoku.