Leiodes masatsugui, 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 : 53-57

9. Leiodes masatsugui sp. nov.

Japanese name: Azuma-ô-tamakinokomushi ( Figs. 30–32 , 112 )

Type locality. Japan, Honshu, Saitama Pref., Ohtaki Village, Nakatsukawa-keikoku, Oku-Chichibu-rindô (alt. 1300m).

Type material. JAPAN: HONSHU: HOLOTYPE, ♂, Saitama Pref., Ohtaki Village, Nakatsukawa-keikoku, Oku-Chichibu-rindô (alt. 1300m), 30.vii.–7.viii.2004, K. Arai & S. Arai leg. ( FIT) ( MNHAH); 1 ♂, 1 ♀, same data as holotype ( FUFJ); 1 ♀, Saitama Pref., Naguri Village , Mt. Arimayama (alt. 1200 m), 17.–24.ix.2004, K. Arai & S. Arai leg. ( FIT) ( FUFJ); 1 ♂, Tokyo Pref., Hinohara Village , Mt. Mitôsan (alt. 1100m), 16.–23.vii.2008, H. Takano leg. ( FIT) ( FUFJ); 2 ♂♂, same data as the former except for the date, 23–30.vii.2008; 2 ♂♂, 1 ♀, Yamanashi Pref., Ôtsuki City, Matsuhime-tôge (alt. 1250m), 1–8.vii.2004, S. Nomura leg. ( FUFJ); 1 ♀, Tochigi Pref., Sano City, Mt. Himuroyama (alt. 1000m), 21–26.v.2011, H. Ohkawa leg. ( FIT) ( FUFJ); 1 ♂, Miyagi Pref., Sendai City, Futakuchi-rindô , 25.v.–1.vi.2005, M. Oikawa leg. ( FIT) ( FUFJ); 1 ♀, Miyagi Pref., Sendai City, Mt. Izumigadake , Kuwanuma-rindô, 12.–22.vii.2009, M. Oikawa leg. ( FIT) ( FUFJ); 1 ♂, 1 ♀, Yamagata Pref., Ôkura Village , Yunodai , 24.v.–3.vi.2006, M. Oikawa leg. ( FIT) ( FUFJ); 2 ♂♂, same data as the former except for the date, 17.vi.–16.vii.2006; 2 ♂♂, 2 ♀♀, Yamagata Pref., Ôkura Village , Fujitasawa, 17.–25.vi.2006, M. Oikawa leg. ( FUFJ); 1 ♂, 2 ♀♀, Yamagata Pref., Nishikawa Town , Shidu, 22–28.vi.2008, M. Oikawa leg. ( FIT) ( FUFJ); 1♀, Akita Pref., Yurihonjô City, Chôkai-chô , Sarukura , 16.–24.ix.2005, M. Oikawa leg. ( FUFJ).

Diagnosis. Body 3.6–3.8 mm long, ca. 1.6× as long as wide. Dorsum brown or light brown. Each elytron with distinct nine rows of punctures and subhumeral row as long as ca. 1/3 of elytral length. Mesoventrite without distinct excavation between median carina and transverse carina. Median carina of mesoventrite low. Mesotibiae without sexual dimorphism. Male metatibiae distinctly curved. Female abdominal sternite 8 with two distinct projections near both sides of anterior margin.

Description. Measurements of holotype: Body length 3.7 mm; head 0.58 mm in length and 1.0 mm in width; pronotum 1.1 mm in length and 1.9 mm in width; elytra 2.5 mm in length and 2.2 mm in width.

Coloration. Dorsum shining and almost unicolor, brown or light brown; antennomeres 1–6 and 8 brown; antennomeres 7, 9, 10, and basal 3/5 of antennomere 11 dark brown; apical 2/5 of antennomere 11 light brown; legs brown or light brown; all tarsi slightly paler than remaining parts of legs; mesoventrite and metaventrite brown; abdominal ventrites light brown.

Body 3.6–3.8 mm in length, ca. 1.6× as long as wide.

Head ca. 1.7× as wide as long, ca. 0.52× as long as and 0.53× as wide as pronotum, distinctly and densely punctate ( Fig. 30A ), usually bearing some large punctures ( Fig. 30A ); antennomeres 1–4 each longer than wide; remaining antennomeres each wider than long; antennomere 11 oval ( Fig. 30C ); relative lengths of antennomeres 2 to 11 – 3.3: 3.3: 1.9: 1.4: 1.1: 3.0: 1.0: 3.4: 3.1: 4.3.

Pronotum ca. 1.7× as wide as long, ca. 0.45× as long as and 0.83× as wide as elytra, widest near base, simply and very feebly curved at posterior margin, distinctly and densely punctate, punctation similar to that on head ( Fig. 30A ).

Scutellum distinctly punctate.

Elytra ca. 1.1× as long as wide in dorsal view, widest ca. at basal 1/3 or 2/5 ( Fig. 30A ), not transversely strigose; each elytron bearing nine rows of punctures with small number of large punctures and moderate number of very fine punctures between rows ( Fig. 30D ); row 9 invisible in dorsal view, subhumeral row as long as ca. 1/3 of elytral length ( Fig. 30B ); elytral rows composed of larger punctures than those of pronotum ( Fig. 30A ); sutural stria fine, arising from apex to ca. apical half of elytral length.

Metathoracic wings fully developed.

Mesoventrite strongly microreticulate, impunctate, almost glabrous, without distinct excavation between median carina and transverse carina ( Fig. 30E ); median carina of mesoventrite low ( Fig. 30E ); metaventrite without sexual dimorphism, sparsely pubescent, distinctly microreticulate except almost smooth middle portion.

Legs showing sexual dimorphism in shape of protarsi, protibiae, mesotarsi, and metatibiae; metafemur robust, with small dorsal posteroapical projection ( Figs. 31H, 31I ).

Male. Protibiae gradually and distinctly widening from base towards apex at internal margins ( Fig. 31F ); tarsomeres 2–4 of protarsi and mesotarsi a little expanded ( Fig. 31A ); metatibiae distinctly or very feebly curved inwards ( Figs. 31C, 31D ); abdominal sternite 8 moderately curved ( Fig. 32C ); aedeagus relatively robust ( Figs. 32A, 32B ); median lobe a little protuberant apically ( Fig. 32A ), pointed apically in lateral view ( Fig. 32B ); each paramere bearing two apical setae and one transparent very small lobe at apex ( Fig. 32A ); inner sac with some small sclerites ( Fig. 32A ).

Female. Protibiae very feebly widening from base towards apex at internal margins ( Fig. 31G ); protarsi and mesotarsi slender ( Fig. 31B ); metatibiae almost straight ( Fig. 31E ); abdominal sternite 8 with two projections near sides of anterior margin ( Fig. 32D ); coxites and stylus as shown in Fig. 32E .

Differential diagnosis. Leiodes masatsugui sp. nov. has a characteristic female abdominal sternite 8 with two distinct projections situated near both sides of the anterior margin ( Fig. 32D ). This species is similar to L. babai Nakane, 1989 in having a thick aedeagus, but can be distinguished from it by the relatively large body (3.5–3.8 mm) and mesoventrite without a distinct excavation between the median carina and transverse carina ( Fig. 30E ). In contrast, L. babai has a relatively small body (2.7–3.0 mm) and mesoventrite with a distinct excavation ( Fig. 7E ). Leiodes masatsugui sp. nov. is also similar to L. silesiaca (Kraatz, 1852) inhabiting the Russian Far East in having a robust body, but can be separated from it by having the median lobe protuberant apically in dorsal view ( Fig. 32A ). In contrast, L. silesiaca has the median lobe simply triangular apically.

Morphological variability. The shape of the male metatibiae of L. masatsugui show individual variation ( Figs. 31C , 32D ) which is not regional, but is correlated to the body size. Small males do not have distinct secondary sexual characters on the metatibiae. Figs. 31C and 31D were drawn from male specimens whose body sizes are 4.0 mm and 3.2 mm, respectively.

Etymology. This species is dedicated to Mr. Masatsugu Oikawa, who kindly offered the valuable specimens of Leiodes for this study.

Distribution. Japan: eastern Honshu.

Figures

Fig.30. Leiodes masatsugui sp. nov.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: 0.5 mm for C; III: 0.5 mm for E.

Fig. 31. Leiodes masatsugui sp. nov.A – male fore leg, ventral view; B – female fore leg, ventral view; C – hind leg of male (body size: 4 mm), ventral view; D – ditto (body size: 3.2 mm); 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 A–C and E; II: 1 mm for D; III: 0.2 mm for F and G; IV: 0.2 mm for H and I.

Fig. 32. Leiodes masatsugui sp. nov.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. 112. Distribution of Leiodes koreana group in Japan. Solid line – L. masatsugui sp. nov.; broken line – L. koreana Park & Ahn, 2007; (●) L. toyoshimai sp. nov.; arrow – suggested migration pathway of L.koreana group from the continent to Japan.

Fig. 7. Leiodes babai Nakane, 1989.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: 0.5 mm for C; III: 0.2 mm for E.