Acanthosoma ishiharai YAMAMOTO et M. HAYASHI, 2011

Acanthosoma ishiharai YAMAMOTO et M. HAYASHI View in CoL , sp. nov.

( Figs. 1-6)

Description. Body ( Fig. 1) ovoid, gently narrowed posteriad, with remarkable forceps-like caudal projections in males; dorsum green, densely punctate, with reddish humeral angles and posterior end of abdomen; ventral surface greenish yellow, reddish on posterior end. Head ( Fig. 1) green, sparsely with fine punctures except around eyes; tylus narrow, rounded apically, with a pair of narrow lines on basal part; jugum triangular. Antennal segment I greenish brown except nigrescent apex; segments II and basal half of III dark brown; segments IV and V, and apical half of III nigrescent; segments III-V densely pubescent except for base of III; segment III shortest in length, segment IV longest. Maxillary plate with a small conical tubercle. Rostrum greenish yellow, blackish at apex of segment IV, reaching between middle and hind coxae. Pronotum ( Fig. 1) green, densely with dark punctures except for calli; anterior corner with a small triangular projection; humeral angle widely reddish, triangularly protruding, slightly sinuate posteriorly; color of humeral angle sometimes tinged with orange. Scutellum ( Fig. 1) green, densely punctate, with pale apical tip. Corium ( Fig. 1) and clavus green, with dark punctures finer than those of pronotum and scutellum; membrane blackish brown. Mesosternal carina round in lateral view, with anterior lobe reaching head. Femur pale green, slightly darkened apically; tibia green, brownish apically; tarsus brown, darkened on apex of tarsomere II; apex of claw fuscous. Abdominal terga reddish yellow. Connexiva III-VI pale green with red tinge, slightly darkened on both anterior and posterior corners; connexivum VII red, blackish on anterior margin. Abdominal sterna pale green, reddish on posterolateral corners ofVII, impunctate; male posterolateral corner ofVII round.

Male genitalia ( Figs. 2-5). Pygophore ( Figs. 2, 3) red, with a pair oflong projections on dorsolateral rims; each projection elongate, slightly tapering, narrowly sclerotized on ventral margin, without apical hairs; angle formed by middle of dorsal rim and apices of projections more than 100°; ventral rim with two round lateral emargination; paramere ( Figs. 2, 4) elongate, bent outwards at apical 1/3, with two sclerotized apical denticles; base of paramere extend inwards, with a small subapical sclerotized lobe; proctiger ( Fig. 2) trapezoidal, strongly marginate, with a large projection flattened apically. A pair of lobes of conjunctiva ( Fig. 5) elongate; basal part of vesica ( Fig. 5) with a large membranal appendage; apical part of vesica long, weakly coiled.

Female genitalia ( Fig. 6). Posterior margin of paratergum VIII arcuate, moderately projected as in Fig. 6; paratergum IX rectangular, gently narrowed anterolaterally, strongly arcuate on inner margin.

Measurements [3 (n = 15) / Sj2 (n = 4), (mean)]. Body length between apex of head and apices ofhemelytra 14.5-16.3 (15.5) I 16.7-18.2 (17.4); width ofhead including eyes 2.63-2.91 (2.73)/ 2.82-3.10 (2.94); length of antenna! segment I as 1.60-1.97 (1.83)/ 1.69-1.97 (1.86), segment II as 1.97-2.35 (2.16)/ 1.97-2.16 (2.09), segment III as 1.50- 1.88 (1.73)/ 1.50-1.97 (1.76), segment IV as 2.16-2.54 (2.35)/ 2.16-2.44 (2.33), segment Vas 1.79-2.19 (1.98)/ 1.79-1.97 (1.90); maximum width of pronotum 7.61-8.93 (8.45)/, 9.21-10.50 (9.87); width of scutellum 3.85--4.43 (4.23)/ 4.61-5.17 (5.01); length of scutellum 4.32-5.22 (4.80)/ 5.17-5.92 (5.57); length of fore femur as 3.20-3.76 (3.59)/ 3.48-3.95 (3.71), fore tibia as 3.29-3.76 (3.57)/ 3.38-3.95 (3.67), fore tarsus as 1.32-1.58 (1.44)/ 1.41-1.50 (1.46), middle femur as 3.85-5.08 (4.19)/ 4.04-4.61 (4.37), middle tibia as 3.57-4.98 (3.87)/ 3.57-4.23 (3.85), middle tarsus as 1.22-1.50 (1.40)/ 1.41-1.50 (1.43), hind femur as 4.51-5.17 (4.87)/ 4.79-5.64 (5.22), hind tibia as 4.61-5.11 (4.86)/ 4.51-5.26 (4.84), hind tarsus as 1.32-1.50 (1.40)/ 1.32-1.50 (1.43).

Holotype. a ( Fig. 2), [Honshu] " NEBAZAWA Oku-Nikko JAPAN July, 14, 1935 Collect. Y. SUDA", "HOLOTYPE Acanthosoma nikkoense Ishihara" [handwriting label] ( EUMJ) .

Paratypes. [Honshu] Mt. Takayama , Towada (Towada-ko), Aomori Pref ., 1a, 25. vi. 1999, S. YAMAUCHI ( APMA) ; Tashiro-yama , Nikko (Kuriyama), Tochigi Pref., 1 ~, 12. ix. 1997, K. FUKUDA ( SUU) ; Shojin-zawa , Shioya, Tochigi Pref., 1a, 14. v. 1996, K. SATO ( TPM) ; 1 ~ (Fig. lb), 25. x. 1996, K. SATO ( TPM) ; Urayama, Chichibu , Saitama Pref., 1a, 13. viii. 2009 (light trap), M. HAYASHI et al. ( SUU) ; Kandatsu-ishishiro , Yuzawa, Niigata Pref., 1a ( Figs. 4, 5), 30. x. 1994, K. HAGA ( OMO) ; Yabusawa (1,320- 1,690 m), Enzan, Oku-Chichibu Mts. , Yamanashi Pref., 1a, 16. x. 2000, M. HAYASHI et al. ( SUU) GoogleMaps ; Kakuma Valley, Ueda ( Sanada ), Nagano Pref., 1a ( Fig. 3a), 8. ix. 1995, M. HAYASHI et al. ( SUU) ; Honsawa-rindo , Azumino (Horigane), Nagano Pref., 1 ~ ( Fig. 6a), 13.vi. 1996, A. YAMAMOTO ( OMO) ; Mt. Ohginosen , Hyogo Pref., 1a, 8. vii. 1962, N. OHIANI ( OMNH). [ Shikoku ] Mt. Kotsu-zan, Tokushima Pref., lo', 25. v. ( NSMT) ; Omogokei , Ehime Pref., lo', 15. v. 1955, T. EDASHIGE ( EUMJ) ; Nishikuma-keikoku , Kami (Monobe), Kochi Pref., 2o', 1 ~, 26. viii. 2000, M. TAKAI ( SUU) ; 2o', 18. viii. 2001, T. Beppu ( OMO) ; Befu , Kami (Monobe), Kochi Pref., 2o' (one shown in Fig. la), 5. v. 2002, M. TAKAI ( OMO) ; Tengu-kogen , Tsuno (Higashi-Tsuno), Kochi Pref., lo', 17. viii. 2002, M. TAKAI ( OMO) .

Distribution. Japan (Honshu, Shikoku).

Etymology. The species name is in honor of the late Dr. Tamotsu ISHIHARA, Prof. emerit. of Ehime University, Matsuyama, who first recognized and confirmed this bug new to science.

Remarks. The new species is similar in general appearance to Acanthosoma labiduroides JAK.OVLEV, 1880 and A.fmficula JAK.OVLEV, 1880 , but it is distinguished by the nigrescent antennal segments II-V, the widely divergent male pygophoral projections with no apical hairs ( Fig. 2), and the female paratergite VIII roundly projected but not so distinct as that of Acanthosoma labiduroides ( Fig. 5). The new bugs may inhabit montane deciduous forests of Honshu and Shikoku, and collected by the light trap. Host plants are unknown.