Aleochara (Emplenota) yamato Yamamoto & Maruyama

Yamamoto, Shûhei & Maruyama, Munetoshi, 2012, Revision of the Seashore-dwelling Subgenera Emplenota Casey and Triochara Bernhauer (Coleoptera: Staphylinidae: genus Aleochara) from Japan, Zootaxa 3517, pp. 1-52 : 26-28

Aleochara (Emplenota) yamato Yamamoto & Maruyama n. sp.

( Figs. 4 , 46–52 , 97 , 103 )

Type series. Holotype, 3, JAPAN: Kakanokuketo, Shimane-chô, Matsue-shi, Shimane-ken, Honshû (35.578N, 133.050E), 1 IV 2009, Hayama-T. (shingle beach; KUM).

Paratypes, 4 3, 4 Ƥ, same data as holotype (KUM).

Description. Body ( Fig. 4 ): extremely large; robust; somewhat thickly elongated; entire surface of pronotum and elytra covered with numerous brown hairs somewhat densely, but inconspicuous; somewhat large hexagonal microstructures on dorsal surface of head, pronotum and elytra; distinct and prominent punctures on dorsal surface of head and pronotum; punctures on elytra deep. Colour ( Figs. 4, 6 ): gland colour blackish brown to black; legs, especially tarsal segments, reddish brown: maxillary and labial palpi blackish brown to reddish brown; antennae blackish brown and partly light brown. Head ( Fig. 6 ): somewhat wide (HW/HL = 1.25), widest at just behind eyes; impunctured area of forepart flattened but of basal part prominently and spherically swollen (not carinate; see, Fig. 6 : arrow); surface sparsely covered with medium sized setae; uniformly observed huge hexagonal reticulations on dorsal surface with relatively large distinct punctures. Antennae: thick and robust; segment I, not so thick, nearly 3.0 times as long as broad; segment II clearly shorter than I; segment III clearly longer than II; segment IV short barrel shape, slightly longer than width; segments V and VI barrel like shape; segments VII to X clearly transverse; segment XI, about 2.0 times as long as broad; relative length (width) of segments from basal to apical: 9(3): 4.5(2.5): 6.5(2.5): 3.5(3): 3.5(4): 3.5(4): 3.5(5): 3.5(5): 3.5(5): 3.5(5): 8(4). Thorax: pronotum moderately wider than long (PW/PL =1.24), a little broader than head (PW/HW =1.36); strongly constricted near base; surface mat with large hexagonal reticulations and deep distinct punctures. Inter coxal cavities of mesoventrite very narrowly separated. Apex of inter coxal process of mesoventrite extremely sharp with exceedingly short carina (almost nothing) along midline, about 0.11 times as long as mesoventrite. Metaventrite, about 1.8 times as long as mesoventrite. Inter coxal process of metaventrite broad and short, rounded apically. Legs: hindtibia somewhat long, nearly same length as elytra; relative lengths of tarsomeres from basal to apical: 7: 4: 4: 3.5: 16 in foretarsus, 11: 7.5: 7.5: 7.5: 20.5 in midtarsus, 12: 11: 8: 8: 23 in hindtarsus.

[Male]: tergite VIII ( Fig. 46 ) clearly emarginated medially at posterior margin, with around 8 macrosetae. Sternite VIII ( Fig. 48 ) with about 7 macrosetae and around 7 thin macrosetae; posterior margin strongly rounded. Aedeagus ( Figs. 50–51 ) extremely large; median lobe elongated and moderately narrowed toward apex, elongated pyriform in ventral view ( Fig. 51 ); a pair of subapico-ventral projections straight, quite thick and robust in lateral aspect ( Fig. 50 ); basal swelling of aedeagus, circularly curved and pointed in lateral view ( Fig. 50 ); apical lobe of median lobe long and moderately curved in lateral view ( Fig. 50 ), and clearly isosceles shape in ventral view ( Fig. 51 ); flagellum shorter than the whole length of median lobe ( Figs. 50–51 ).

[Female]: tergite VIII ( Fig. 47 ) strongly emarginated at posterior margin, with around 4 macrosetae. Shape of sternite VIII ( Fig. 49 ) closely similar to that of male, but pointed somewhat weakly, with 5 macrosetae. Spermatheca ( Fig. 52 ): spermathecal head (sh) about twice longer than apical portion of spermathecal stem; neck of spermatheca very long, somewhat longer than (sh); collar thick; basal portion of spermathecal stem (sb) slightly narrowing toward base, with bent at base; sclerotized portion of spermathecal stem short, erect and sclerotized; each part of spermatheca except for membraneous portion of spermathecal duct (sm) entirely and moderately sclerotized; (sm) moderate in length.

Measurements (male: n=5): BL, 4.80–5.99 (5.63±0.47); FBL, 2.59–2.96 (2.76±0.19); HL, 0.65–0.78 (0.71±0.06); HW, 0.81–0.95 (0.89±0.06); AL, 1.46–1.76 (1.59±0.14); PL, 0.87–1.06 (0.98±0.07); PW, 1.15–1.27 (1.22±0.06); EL, 0.94–1.20 (1.03±0.11); EW, 1.03–1.71 (1.46±0.27); HTL, 0.92–1.13 (1.00±0.09).

Measurements (female: n=3): BL, 5.50–6.25 (5.95±0.40); FBL, 2.73–2.89 (2.82±0.08); HL, 0.73–0.79 (0.75±0.03); HW, 0.88–0.96 (0.93±0.04); AL, 1.61–1.69 (1.64±0.04); PL, 0.94–1.06 (1.02±0.07); PW, 1.16–1.32 (1.26±0.09); EL, 1.00–1.15 (1.06±0.08); EW, 1.56–1.66 (1.63±0.06); HTL, 0.91–1.04 (0.98±0.07).

Distribution. [ JAPAN]: Honshû (Shimane-ken). See, Fig. 103 .

Diagnosis. This species, Aleochara yamato , can be easily differentiated from other congeners by a combination of features as follows: very rare species (only one locality known so far); body extremely large (BL =5.79; Fig. 4 ); dorsal surface of forebody with prominently deep and distinct punctures; dorsal surface of impunctured area of head largely flattened but of basal part prominently and spherically swollen (see, Fig. 6 : arrow); head capsule transverse (HW/HL =1.25: other Japanese species ≈1.14); quite short carina on mesoventrite about 0.1 times as long as mesoventrite. [Male]: posterior margin of tergite VIII ( Fig. 46 ) prominently emarginated; outer margin of sternite VIII ( Fig. 48 ) clearly rounded in the middle; median lobe of aedeagus ( Figs. 50–51 ) large and elongated; subapico-ventral projections on median lobe straight, thick and robust in lateral view ( Fig. 50 ); apical lobe of median lobe long and moderately curved in lateral aspect ( Fig. 50 ); basal swelling ( Fig. 50 ) of median lobe strongly rounded toward ventral margin as in A. puetzi ( Fig. 27 ). [Female]: posterior margin of tergite VIII ( Fig. 47 ) strongly emarginated; spermatheca ( Fig. 52 ) unique in shape; combined length of (sh) and (sn) very long, more than 4 times as apical portion of spermathecal stem.

Etymology. The specific epithet yamato is an old name of Japan.

Remarks. The species clearly differs from the other Emplenota species by having a larger body, prominent spherical swelling on the dorsal surface of the head base (see, Fig. 6 ), and deep punctures in the fore body. In addition, tergite VIII and sternite VIII of Aleochara yamato are unique in both sexes. Only nine specimens have been obtained to date. Type materials were collected by Mr. T. Hayama in Shimane-ken (Honshû) as with Aleochara hayamai . Ecological information for this species, including detailed habitats and seasonal patterns, is not known.

Figures

FIGURES 1 – 7. Japanese species of Aleochara (Emplenota) (Figs. 1 – 5, habitus). 1. Aleochara (Emplenota) fucicola; 2. A. (E.) puetzi; 3. A. (E.) hayamai; 4. A. (E.) yamato; 5. A. (E.) segregata; 6. dorsal head of A. yamato; 7. mesoventrite and metaventrite of A. fucicola in ventral view.

FIGURES 46 – 52. Terminalia of Aleochara (Emplenota) yamato. 46. tergite VIII of male; 47. tergite VIII of female; 48. sternite VIII of male; 49. sternite VIII of female; 50. male genitalia: median lobe of aedeagus in lateral view; 51. male genitalia: median lobe of aedeagus in ventral view; 52. female genitalia: spermatheca.

FIGURES 93 – 100. Collecting sites of the subgenera Emplenota and Triochara of the genus Aleochara in Japan. 93. Kourakaigan (Matsue-shi, Shimane-ken; habitat of A. (E.) fucicola, A. (E.) segregata, and A. (E.) hayamai; arrow); 94. drifted seaweed and flotsams on beach (Koura-kaigan); 95. Mochirippu-numa (Hamanaka-chô, Hokkaidô; A. (E.) puetzi, arrow); 96. Ochiishi-misaki (Nemuro-shi, Hokkaidô; A. puetzi); 97. Kakanokuketo (Shimane-ken; habitat of A. fucicola, A. segregata, A. hayamai, and the type locality of A. (E.) yamato; A. fucicola, arrow); 98. Hamamatsu (Nemuro-shi, Hokkaidô; habitat of A. (T.) nubis, arrow); 99. drifted seaweed on beach (Hamamatsu); 100. mating behaviour of A. nubis at Hamamatsu.

FIGURES 101 – 103. Collecting localities of Aleochara (Emplenota) spp. based on specimens examined. 101. A. (E.) fucicola (Pointed by black circle); 102. A. (E.) segregata (Pointed by black square); 103. A. (E.) puetzi (Pointed by black triangle); A. (E.) hayamai (Pointed by black diamond); A. (E.) yamato (Pointed by black star).

FIGURES 23 – 29. Terminalia of Aleochara (Emplenota) puetzi. 23. tergite VIII of male; 24. tergite VIII of female; 25. sternite VIII of male; 26. sternite VIII of female; 27. male genitalia: median lobe of aedeagus in lateral view; 28. male genitalia: median lobe of aedeagus in ventral view; 29. female genitalia: spermatheca.