Acanthosoma asahinai Ishihara, 1943

Tsai, Jing-Fu & Rédei, Dávid, 2015, The genus Acanthosoma in Taiwan (Hemiptera: Heteroptera: Acanthosomatidae), Acta Entomologica Musei Nationalis Pragae 55 (2), pp. 625-664 : 632-634

Acanthosoma asahinai Ishihara, 1943

( Figs 6–7 , 25–28 , 47–49 , 64–67 )

Acanthosoma asahinai Ishihara, 1943: 495 . Holotype: J, Formosa [= Taiwan], Taityū- syū [= Nantou County], Mareppa-Oiwake [= Renai, Tsuifeng]; ELKU!

Acanthosoma asahinai: HSIAO & LIU (1977: 175) (listed, distribution), HUA (2000: 166) (listed, distribution), GÖLL- NER- SCHEIDING (2006: 166) (catalogue, distribution), ZHENG & LIN (2013: 92) (partim) (redescription, photo).

Type material examined. HOLOTYPE: J, ‘ 20 VIII 1936 \ MAREPPA \ ---OIWAKE’ [pink, printed], ‘S. Asahina \

<collected> [in Japanese script]’ [handwritten], ‘No. 464’ [yellow, printed], ‘ HOLOTYPE \ Acanthosoma \ asahinai

\ Ishihara’ [orange, handwritten]; pinned, segments III–IV of left and IV of right antenna, right mid leg, tarsus of left hind leg lacking; deposited in ELKU.

Material examined. TAIWAN: YILAN CO.: Dong Ao Ling , 18.iii.2009, leg. S.W. Hou (1 J NCHU) ; Yuanyang

Lake 100, logging Rd. 16K, 29.iii.2010, leg. S.F. Huang & S.J. Huang (1 ♀ NCHU). TAICHUNG CO.: Anmashan,

13.xii.2002, leg. C.S. Lin, sweeping net, NMNS ENT 3973–942 (1 ♀ NMNS). NANTOU CO.: Tunyuan, 5.vi.2003, leg. J.F. Tsai (1 J [dissected], 1 J 1 ♀ NCHU); Sungk[u]ang, 29.vii.1985, leg. T. Hattori, NSMT-I-He 34906 (1 ♀ NSMT); Huisun Forest Station Emergency rd. to Huisun Mon., 10.ix.2010, 24.0842°N 121.0272°E, pine forest, 1000 m acc. Ti-25a Colls, ex UV light sheet, leg. C. Skinner & W. Hunting (1 ♀ NCHU); Huisun Experimental Forest Station, 12.xi.2010, ex Rhus javanica L. var. roxburghii (DC.) Rehder & E.H. Wilson , leg. Z.Y. Wang (1 ♀ NCHU, 1 J 1 ♀ NCHU > SEHU); Jenai, Chunyang, 31.v.1995, UV light, leg. M.L. Chan & C.S. Lin, 2005–141 (1 ♀ NMNS); Meifeng, 18.xii.2001 – 19.ii.2002, Malaise trap, leg. C.S. Lin & W.T. Yang, NMNS ENT 4467–2 (1 ♀ NMNS); Nanshanxi, 6.ix.1994 (1 J OMHJ); Shizitou, 18.x.1994 (1 J 1 ♀ OMHJ). MIAOLI CO.: Simaxian logging Rd., 8.ix.2010, leg. Y.C. Liao (1 J NCHU); Nanzhuang, Luhu, 9.ix.2010, ex Rhus javanica L. var. roxburghii (DC.) Rehder & E.H. Wilson , leg. Y.C. Liao (1 J HNHM). KAOHSIUNG CO.: Yushan Nat. Pk. 24–28.x.1990, 23.28°N 120.54°E 1800–1900m, leg. C.K. Starr & S.S. Lu, NMNS ENT 764–68 (1 J NMNS). PINGTUNG CO.: Mt. Dahan, ex Rhus javanica L. var. roxburghii (DC.) Rehder & E.H. Wilson , leg. Y.X. Shieh (1 ♀ HNHM).

Diagnosis. This species is readily recognized based on the horizontally directed, acute humeral processes of both sexes, the conspicuous subbasal dilation of the hind tibia of the male, and the elongate, posteriorly directed projections of the male genital capsule. The detailed original description ( ISHIHARA 1943) allows unambiguous recognition of the species; as an addition, the male ( Figs 6–7 , 25–28 ) and female ( Figs 48–49 ) genitalia are described and figured in the present paper. The female of this species is similar in size, colour, and in the presence of sharp humeral processes to that of A. fallax , but the broadly rounded posterior margin of laterotergites VIII sharply differs from the condition found in the latter species.

Description of male and female terminalia. Male. Genital capsule ( Figs 6–7 ) with a pair of elongate posterolateral projections directed posteriad, running subparallel, slightly curved mesad subapically, apically with a tuft of setae; dorsal rim with a deep, obtuse concavity at midline, provided with several fine setae; ventral infolding with a pair of fine setal tufts and a pair of heavily sclerotized and pigmented denticles laterad of paramere sockets. Paramere ( Figs 25–28 ) T-shaped, dorsal arm with blunt apex, without distinct subapical denticle, ventral arm bird-head-shaped apically. Female ( Figs 48–49 ). Posterior margin of ventrite VII with a deep, broadly U-shaped incision surrounding valvifers VIII; tergite VIII with dark markings proximally and distally as in Fig. 48 ; posterior margin of laterotergites VIII broadly rounded, far surpassing posterolateral angles of abdominal ventrite VII, mesal portion (surrounding postgenital segments) with dark marking; Pendergrast’s organs of ventrites VI and VII subelliptical, of equal size.

Measurements (in mm). Body length to apex of membrane 14.3–15.9 (J) / 15.9–17.2 (♀); to imaginary line connecting apices of projections of genital capsule 15.2–17.1 (J)

Bionomics. Adults, larvae and eggs of this species are frequently observed on Rhus javanica L. var. roxburghii (DC.) Rehder & E.H. Wilson (Anacardiaceae) which is apparently its host plant. The breeding season is from September to October.

Distribution. The species is apparently endemic to Taiwan and it is relatively frequent in the Machilus - Castanopsis forest zone of the moutainous regions ranging between 500–1800 m in altitude.

Remarks. Acanthosoma asahinai was described based on a single male from ‘Mareppa-Oiwake’ (now Renai, Tsuifeng) in Taiwan. The identity of the species was confirmed by reexamination of the holotype during the present study.

Except of ZHENG & LIN (2013) no subsequent authors provided original data on the species. The top left photo in p. 92 of ZHENG & LIN (2013) shows A. asahinai but the top right one is A. fallax sp. nov.; their redescription of ‘ A. asahinai ’ includes characters of both species. The male is redescribed and the female is described for the first time in this paper.

The new species belongs to the Acanthosoma forfex species group hereby defined in the following way: genital capsule with a pair of greatly elongate posterolateral projections; paramere T-shaped, with a long dorsal and a somewhat shorter ventral arm. The group comprises the following species: A. asahinai , A. forcipatum Reuter, 1881 , A. forfex Dallas, 1851 , A. forficula Jakovlev, 1880 , A. ishiharai Yamamoto & Hayashi, 2011 , A. labiduroides Jakovlev, 1880 , the newly described A. fallax sp. nov., and perhaps A. hampsoni ( Distant, 1900) (the latter one doubtfully associated). Acanthosoma asahinai is apparently sister to A. labiduroides based on the high similarity of the genital capsule and female terminalia. A study on the molecular phylogeny of the family also supports the sister relationship of the two species (TSAI et al., in preparation).

Figures

Figs 1–10.Acanthosoma spp., males. 1 – A.atayal sp.nov., posterior part of abdomen, ventral view; 2 – same, genital capsule and exposed part of segment VIII, ventral view; 3 – same, genital capsule, lateral view; 4 – A. haemorrhoidale formosanum subsp. nov., holotype, genital capsule, posterior view; 5 – A.haemorrhoidale haemorrhoidale (Linnaeus, 1758) (Spain: Fuente Dé, HNHM), genital capsule, posterior view; 6 – A. asahinai Ishihara, 1943, posterior part of abdomen, ventral view; 7 – same, genital capsule, ventral view; 8 – A. fallax sp. nov., posterior part of abdomen, ventral view; 9 – same, genital capsule, ventral view; 10 – A. pugnax sp. nov., genital capsule and exposed part of segment VIII, ventral view. Scales in mm.

Figs 20–44. Acanthosoma spp., right parameres in different views. 20–21 – A. atayal sp. nov.; 22 – A. haemorrhoidale formosanum subsp. nov., holotype; 23 – A. haemorrhoidale ouchii Ishihara, 1950 (China: Sichuan, Mt. Emei, USNM); 24 – A. haemorrhoidale haemorrhoidale (Linnaeus, 1758) (Spain: Fuente Dé, HNHM); 25–28 – A. asahinai Ishihara, 1943; 29–32 – A. fallax sp. nov.; 33–36 – A. pugnax sp. nov.; 37–39 – A. axicia sp. nov.; 40–41 – A. laevicorne Dallas, 1851; 42–44 – A. expansum Horváth, 1905. Scales in mm.

Figs 45–51. Acanthosoma spp. 45 – A. atayal sp. nov., female terminalia, posteroventral view; 46 – A. haemorrhoidale formosanum subsp. nov., paratype, female terminalia, posteroventral view; 47 – A. asahinai Ishihara, 1943, hind tibia of male; 48 – same, female terminalia, dorsal view; 49 – same, posteroventral view; 50 – A. fallax sp. nov., female terminalia, dorsal view; 51 – same, posteroventral view. PO6, PO7 = Pendergrast’s organs of ventrites VI and VII, respectively. Scales in mm.

Figs 64–67. Acanthosoma asahinai Ishihara, 1943. 64–65 – male; 66–67 – female. Scales in mm.