Aleochara (Emplenota) hayamai 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 : 23-26

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

( Figs. 3 , 38–45 , 93–94, 97 , 103 )

Type series. Holotype, 3, JAPAN: Koura-kaigan, Koura, Kashima-chô, Matue-shi, Shimane-ken, Honshû (35.521N, 132.975E), 18 VII 2010, Yamamoto-S. (by hand with aspirator; under flotsam on sandy beach in the hot daytime; KUM).

Paratypes, JAPAN: [Honshû]: 2 3, Mito beach, Hasse-machi, Miura-shi, Kanagawa-ken (35.177N, 139.620E), 14 V 2009, Watanabe-T. (cWat); 1 3, Inugu (Dôgo Is., Oki-shotô), Okinoshima-chô, Oki-gun, Shimane-ken (36.219N, 133.372E *), 10 XI 2009, Hayama-T. (cHayam); 4 3, 3 Ƥ, Kakanokuketo, Shimane-chô, Matsue-shi, Shimane-ken (35.578N, 133.051E), 1 IV 2009, Hayama-T. (shingle beach; cHayam); 2 3, 2 Ƥ, same data, but 9 VI 2009; 2 3, same data, but 18 VII 2010, Yamamoto-S. (cYam); 1 3, same data, but 19 VII 2010; 1 3, Kaka (Katsura-jima), Shimane-chô, Matsue-shi, Shimane-ken (35.566N, 133.052E), 19 VII 2010, Yamamoto-S.

(by hand pick; sandy beach; under seaweed around evening; cYam); 18 3, 4 Ƥ, Koura-kaigan, Koura, Kashimachô, Matue-shi, Shimane-ken (35.521N, 132.975E), 8-10 VI 2009, Hayama-T. (FIT; cHayam); 31 3, 26 Ƥ, same data, but 18-20 VI 2009; 3 3, same data, but 3-5 VII 2009; 4 3, 8 Ƥ, same data, but 16-18 VII 2009; 8 3, 4 Ƥ, same data, but 17 VII 2010, Yamamoto-S. (by hand pick up with aspirator; under flotsam on sandy beach; KUM); 1 3, 2 Ƥ, same data, but 18 VII 2010 (same data as holotype); 2 3, Sakaura-kaigan, Sakaura-chô, Izumo-shi, Shimane-ken (35.508N, 132.861E), 20 IV 2009, Hayama-T. (cHayam); 1 Ƥ, same data, but 15 V 2009; 1 Ƥ, river mouth of Sakaura-gawa, Sakaura-chô, Izumo-shi, Shimane-ken (35.508N, 132.861E), 13 IV 2008, Hayama-T. (cHayam); 1 3, same data, but 31 IV 2008; 1 3, same data, but 17 V 2008; 1 3, 31 VIII 2008; 1 3, same data, but 5 VIII 2009; 2 3, 1 Ƥ, Owashi-hama, Nakayama, Taisha-chô, Izumo-shi, Shimane-ken (35.433N, 132.634E), 24 III 2009, Hayama-T. (shingle beach; cHayam); 1 3, 1 Ƥ, Akaishihana, Hinomisaki, Taisha-chô, Izumo-shi, Shimane-ken (35.411N, 132.650E *), 2 IV 2009, Hayama-T. (cHayam); 7 Ƥ, same data, but 2-8 V 2009 (FIT); 1 3, Kiami-chô, Masuda-shi, Shimane-ken (34.676N, 131.747E), 10-11 V 2009, Hayama-T. (FIT; cHayam). [Kyûshû]: 1 3, Odo-kôen park, Odo-2chôme 6, Nishi-ku, Fukuoka-shi, Fukuoka-ken (33.596N, 130.311E), 28 VI 2009, Yamamoto-S. (from seaweed on sandy beach with Aleochara (E.) segregata ; cYam); 2 3, Sato (Kamikoshikijima), Sato-machi, Satsumasendai-shi, Kagoshima-ken (31.844N, 129.919E), 11-12 IV 1973, Furuki-Y. ( EEEU).

Description. Body ( Fig. 3 ): small to medium sized, slender body; surface of pronotum and elytra somewhat densely haired by rather short and thin setae; fore-body (head, pronotum and elytra) weakly shining due to extremely minute hexagonal microstructures. Colour ( Fig. 3 ): gland colour complete black; legs dark brown to reddish brown, tarsal segments orange brown to reddish brown: maxillary and labial palpi blackish brown to yellowish brown; antennae blackish brown and partly reddish brown. Head: impunctured area along midline not uniquely elevated at all. Antennae ( Fig. 42 ): entirely slender; slightly longer than combined length of head and pronotum; segment I, nearly 2.8 times as long as broad; segment II somewhat shorter than I; segment III as same length as II; segments IV and V long barrel shape, clearly longer than width; segments VI to VII short barrel shape; segments VIII to X transverse; last segment somewhat long, about 1.7 times as long as broad; relative length (width) of segments from basal to apical: 11(4): 7(3): 6.5(3): 4(3): 4.5(3.5): 4(4): 4(4): 5(5): 6(5): 4.5(5): 10(6). Thorax: pronotum somewhat strongly convex above, with moderately rounded posterior margin; slightly wider than long (PW/PL =1.23), clearly broader than head (PW/HW =1.38), widest just behind middle; surface with extremely minute hexagonal reticulations with inconspicuous punctures. Metaventrite, about 1.6 times as long as mesoventrite. Inter coxal process of mesoventrite sharply pointed with very short carina along midline, about 0.3 times as long as mesoventrite. Inter coxal process of metaventrite broad and somewhat long, and apical margin pointed moderately. Legs: relative lengths of tarsomeres from basal to apical: 4.5: 3: 3: 3: 10 in foretarsus, 6: 5: 5: 5: 13 in midtarsus, 8: 6: 6: 6: 16 in hindtarsus.

[Male]: posterior margin of tergite VIII ( Fig. 38 ) very weakly emarginated medially, with around 7 to 8 macrosetae. Sternite VIII ( Fig. 40 ) with about 12 macrosetae; posterior margin very strongly pointed toward apex, forming triangular. Median lobe of aedeagus ( Figs. 43–44 ) C-curved (sponge-gourd shape) in lateral view ( Fig. 43 ); moderately narrowed apically in ventral view ( Fig. 44 ); a pair of subapico-ventral projections thick, robust and straight in lateral view ( Fig. 43 ); basal swelling of aedeagus, circularly rounded in lateral view ( Fig. 43 ); apical lobe of median lobe very short isosceles shape in ventral aspect ( Fig. 44 ); flagellum extremely longer than the whole length of median lobe ( Figs. 43–44 ).

[Female]: posterior margin of tergite VIII ( Fig. 39 ) slightly rounded, but very weakly emarginated medially, with about 7 macrosetae. Posterior margin of sternite VIII ( Fig. 41 ) rounded or weakly pointed, with around 8 macrosetae. Spermatheca ( Fig. 45 ): spermathecal head as long as apical portion of spermathecal stem; basal portion of spermathecal stem very short and curved; sclerotized portion of spermathecal stem thin and erect; each part of spermatheca except for membraneous portion of spermathecal duct (sm) entirely and very weakly sclerotized; (sm) extremely long in length.

Measurements (male: n=10): BL, 2.94–4.65 (4.00±0.49); FBL, 1.66–2.07 (1.87±0.15); HL, 0.46–0.68 (0.56±0.07); HW, 0.53–0.69 (0.60±0.05); AL, 1.11–1.51 (1.30±0.14); PL, 0.59–0.78 (0.69±0.06); PW, 0.60–0.92 (0.83±0.06); EL, 0.57–0.77 (0.67±0.06); EW, 0.94–1.27 (1.08±0.10); HTL, 0.57–0.79 (0.66±0.07).

Measurements (female: n=10): BL, 3.23–4.64 (4.04±0.38); FBL, 1.50–2.11 (1.91±0.20); HL, 0.44–0.62 (0.55±0.05); HW, 0.51–0.66 (0.60±0.04); AL, 1.03–1.32 (1.18±0.09); PL, 0.53–0.73 (0.66±0.07); PW, 0.68–0.91 (0.83±0.07); EL, 0.62–0.77 (0.69±0.05); EW, 0.87–1.18 (1.07±0.10); HTL, 0.55–0.78 (0.68±0.07).

Distribution. [ JAPAN]: Honshû, Kyûshû, Dôgo Is., Kamikoshiki-jima. See, Fig. 103 .

Diagnosis. Aleochara hayamai is a peculiar species and can be easily discriminated from other Japanese Emplenota species by following character states: small to medium size body (not large species); gland colour completely black and somewhat strongly shining even in mat area of the forebody (hexagonal structures on dorsal surface very minute compared to the other Japanese Emplenota species), and deep punctures of dorsal surface on forebody inconspicuous ( Fig. 3 ); longitudinal impunctured area of head along midline not uniquely elevated at all; lateral margin of pronotum somewhat convex toward anterolaterally; antennae entirely slender, especially segments IV to V which close to long barrel shape rather than spherically short barrel shape ( Fig. 42 ); legs somewhat long and slender (HTL =0.67). [Male]: sternite VIII ( Fig. 40 ) sharply pointed toward posterior, making sharp triangular; median lobe of aedeagus ( Figs. 43–44 ) unique with extremely long flagellum; subapico-ventral projections of median lobe robust and straight in lateral view ( Fig. 43 ). [Female]: spermatheca ( Fig. 45 ) unique in shape; very weakly sclerotized uniformely, with short basal portion of spermathecal stem and extraordinary long membraneous portion of spermathecal duct.

Etymology. The species, Aleochara hayamai , is dedicated to Mr. Takeshi Hayama (Okinawa-ken), who found this species for the first time during his ecological survey of coastal insects in Shimane-ken.

Remarks. Numerous individuals were collected by Mr. T. Hayama in Shimane-ken (Honshû). He researched the entire coastal region of Shimane-ken to study coastal insect ecology and succeeded in collecting a few specimens of A. hayamai . Mr. Hayama discovered its peculiarity and sent us the specimen. We examined more than 2,000 specimens of Emplenota from all over Japan, but this species seems to be rare except in Shimane-ken and we found it from only three other localities. Aleochara hayamai has similar external characters to other Japanese species, however, the species is outstanding by having huge and peculiar male genitalia.

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 38 – 45. Terminalia of Aleochara (Emplenota) hayamai. 38. tergite VIII of male; 39. tergite VIII of female; 40. sternite VIII of male; 41. sternite VIII of female; 42. right antenna of male; 43. male genitalia: median lobe of aedeagus in lateral view; 44. male genitalia: median lobe of aedeagus in ventral view; 45. 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).