Eurystylus ryukyus Yasunaga, Nakatani & Chérot, 2017

Yasunaga, Tomohide, Nakatani, Yukinobu & Chérot, Frédéric, 2017, Review of the mirine plant bug genus Eurystylus Stål from Japan and Taiwan (Hemiptera: Heteroptera: Miridae: Mirinae), with descriptions of two new species, a new synonymy and a new combination, Zootaxa 4227 (3), pp. 301-324 : 312-316

Eurystylus ryukyus Yasunaga, Nakatani & Chérot , n. sp.

Figs 1 B–C, 2D, 3E–G, 4A–C, 5A–C, 6A–B, 7, Tables 1–2

Eurystylus sauteri: Miyamoto & Yasunaga, 1989: 160 (list); Yasunaga, 2001: 233 (diag.); Zheng & Lin, 2003: 328 (diag.); Nozaki et al., 2015: 16 (list) (not Poppius, 1915).

Diagnosis. Recognized by its medium size ( Table 2 ); wholly darkened antennal segment III; yellowish, or somewhat grayish brown pronotum speckled with many pale spots and with a pair of dark brown, small, ovoid spots on pronotal disk; usually largely darkened corium and clavus, irregularly mottled with grayish, mossy maculae; comparatively small-sized male pygophore and parameres ( Fig. 4 A); weakly curved endosomal PL furnished with teeth only at apical 1/3 ( Fig 5 A–B); small, thick-rimmed sclerotized ring ( Fig. 6 A); and Y-shaped dorsal structure ( Fig. 6 B). Most similar to E. sauteri , sympatric in S. Kyushu and Taiwan; distinguished by uniformly dark antennal segment III without pale base, paired dark spots on pronotum ovoid, more clear, and different forms of the male and female genitalia (cf. Figs. 4 A–C, 5A–C, 6A–B vs. 4D–I, 5D–F, 6C–D for sauteri ). Final-instar nymph ( Fig. 2 D) recognized by its almost uniformly whitish green body, antennae and legs; laterally reddish brown pronotum with a pair of small, red, ovoid spots; and two pairs of reddish ocellate spots on abdominal sterna.

Description. Male: Body generally stramineous or grayish brown, partly tinged with red; dorsal surface matte, mottled with pale or grayish brown spots, with three types of vestiture (uniformly distributed, simple, dark, reclining setae, and rather sparsely distributed, golden pubescence and sericeous, scalelike setae). Head yellowish or grayish brown, somewhat darkened anterior to frons; fuscous, velvety spot on lateral margin of frons distinct. Antenna dark brown; segments I and basal half of segment II reddish brown; bases of segments II and IV white; segment III entirely darkened. Labium pale brown, reaching but not exceeding apex of mesocoxa; segments III and IV largely reddish brown. Pronotum usually pale grayish brown, with pair of rather clear dark, ovoid spots on disk, and paler mesal stripe and posterior margin; posterior inner margin of each callus with a narrow, small spot; scutellum with narrow, dark, mesal stripe, minutely speckled with pale, small spots; pleura yellowish brown, matte, with uniformly distributed, silvery, scalelike setae; scent efferent system pale grayish yellow. Hemelytron largely darkened, speckled irregularly with pale grayish, somewhat mossy maculae; cuneus dark brown, with yelloworange mark at middle; membrane pale smoky brown, narrowly semitransparent at middle, with coffee brown veins. Coxae and legs pale grayish or yellowish brown; each coxa partly darkened; all femora brown, mottled with minute pale spots; basal 1/3–1/2 of mesofemur and basal 1/3 of metafemur pale brown; latter usually with ring-like pale annulation at apical 1/3; all tibiae brown; meso- and metatibiae usually reddish, with pale ring at middle; all tarsi pale brown, with extreme apices infuscate. Abdomen grayish brown, with small dark spots at spiracles, with uniformly distributed, silvery, short, reclining setae. Male genitalia ( Figs. 4 A–C; 5A–C): Pygophore and parameres comparatively small ( Fig. 4 A–C); left paramere C-shaped; right paramere weakly curved; endosoma with fully set of five sclerites ( Fig 5 A–B); PL weakly curved and furnished with teeth only at apical 1/3; TL triangularly developed; seminal duct strongly constricted subapically ( Fig. 5 C). Female: As in male. Female genitalia ( Fig. 6 A– B): sclerotized ring small, ovoid, thick-rimmed ( Fig. 6 A); posterior wall of bursae with Y-shaped dorsal structure and rather broad interramal lobe ( Fig. 6 B).

Measurements. See Table 2 .

Etymology. Named for the frequent occurrence of this new species in the Ryukyus , Japan; a noun in apposition.

Biology. Most individuals of this new species were collected from various inflorescences and four plant species were confirmed as the breeding hosts ( Table 1). The adults are sometimes attracted to light traps. Collecting records suggest E. ryukyus has a multivoltine life cycle.

Discussion. This new species has been regarded as E. sauteri since Miyamoto & Yasunaga (1989) listed an earlier record from Ishigaki Island of the Ryukyus , although we now can no longer trace the source. Previously, a species (x) restricted to southern Japan and Taiwan with the entirely darkened antennal segment III and apically toothed endosomal PL was identified as E. sauteri , and its close relative (y), occurring in Honshu, Shikoku and Kyushu, with the bicolored antennal segment III and wholly toothed PL was E. luteus ( Yasunaga, 2001) . Both species are also clearly separated each other by the male genitalia as well as shape of the final-instar immatures ( Fig. 2 B vs. 2C). It was not until we could access images of the holotype of E. sauteri quite recently that we were aware of this misidentification; base of the antennal segment III of the holotype is pale ( Fig. 8 C). Because the species (x) is distributed in both Japan and Taiwan (type locality of sauteri ), no one has doubted of its wrong identity for long time.

On the other hand, the other species (y) was confirmed as true E. sauteri . Accordingly, E. luteus is now suspected to be conspecific with E. sauteri , based on our examinations of the morphological characters including the genitalia and distribution patterns ( Fig. 7 ). To verify the definitive identity for E. luteus , additional information on the female genitalic structures and final-instar immature form of Chinese materials is required.

Holotype ♂: JAPAN: Ryukyus , Okinawa Island, Kunigami Village, Yona , 26.75, 128.22, on Mallotus sp., 20–24 May 1993, T. Yasunaga ( AMNH _PBI 00380484) ( NIAES) . Paratypes. JAPAN: Kyushu: 1♂, Kumamoto Pref., Amakusa City, Ushibuka , Tsuruha-yama Park , 13 Sep 2015, T. Nozaki ( TYCN) ; 1♀, Amakusa City, Onuki Town , same date & collector ( TYCN) ; Kagoshima Pref., Makurazaki City , 6 Nov 1949, J. Sonan ( TYCN) . Amami- Oshima Island: 1♀, Amami [= former Naze] City, Koshuku , 28.37, 129.47, on Deutzia flowers, 6 Apr 1989, T. Yasunaga ( TYCN) ; 1♂ 2♀, Amami Is., Naze City, Chuoh Trail , 20 Jun 1998, H. Miyake ( NIAES) ; 3♂ 4♀, Kinsakubaru , 30 Jun 2000, Y. Nakatani ( NIAES) ; 1♂ 1♀, same locality, 1 Jul 2000, Y. Nakatani ( NIAES) ; 1♂, Shinmura , 23 Jul 1964, S. Miyamoto, Y. Hirashima ( TYCN) ; 1♀, Fukumoto, 28.26, 129.36, R. Noda (TYCN). Kume Island: 3♂ 6♀, Shimajiri , 4 Apr 2014, leg. M.L. Jing ( NMNS) 1♂, same locality and collector, 3 Apr 2014 ( NMNS) . Okinawa Island: 8♂ 1♀, same data as for holotype ( CNC, TYCN) ; 2♂ 1♀, same locality, 9 Apr 1996, Y. Nakatani ( NIAES) ; 4♂ 5♀, same data except for date 15–18 May 1998 ( NIAES) ; 1♂, Okinawa Is., Kunigami, Sate , 24 May 1993, at light, Y. Nakatani ( NIAES) ; 1♂ 4♀, Kunigami Village, Ohkuni-pass , on Meliosma arnottiana , 24 and 29 Jun 1999, T. Yasunaga, M. Takai ( TYCN) ; 2♂ 4♀, same data, 26.7631, 128.2159, by UV light trap ( TYCN) ; 6♂ 6♀, same data, Y. Nakatani ( NIAES) ; 2♂, Kunigami Village, Yonaha-dake , 26.777, 128.222, sweeping broadleaf flowers, 21 May 1993, T. Yasunaga ( TYCN) ; 2♀, same locality, 8 Apr 1996, Y. Nakatani ( NIAES) ; 1♂, Okinawa Is., Higashi, Gesasi , 12 Apr 1996, Y. Nakatani ( NIAES) ; 1♀, Women Village, Kisenbaru , 26.49, 127.91, UV light trap, 24 Oct 1990, M. Hayashi ( TYCN) ; 1♀, Okinawa City, Chibana , 26.36, 127.80, UV light trap, 6 Apr 1990, M. Hayashi ( TYCN) . Ishigaki Island: 2♀, Ban’na Park , 24.38, 124.17, 4 Mar 1999, T. Yasunaga ( TYCN) ; 1♂ 2♀, Mt. Ban’na , 24.3777, 124.1666, 8 and 15 May 1993, T. Yasunaga , 1♀ with USIs (AMNH_PBI 00380485) (TYCN); 1♀, same locality, 27 May 1990, M. Hayashi ( TYCN) ; 2♂, Ban’na Park , 4 Apr 1997, H. Yoshitake ( TYCN) ; 1♀, Omoto–Takeda , 24.41, 124.18, 5 Mar 1999, T. Yasunaga ( TYCN) ; 1♂, Omoto , 16 Oct 1994, M. Takai ( TYCN) ; 1♂, Shiramizu , 24.4193, 124.1622, on Styrax japonica , 3 Mar 1999, T. Yasunaga ( TYCN) ; 1♂, Mt. Omoto-dake , 8 May 1998, at light, Y. Nakatani ( NIAES) ; 1♀, same data except for date 20 Oct 1999 ( NIAES) ; 4♀, Ishigaki Is., Mt. Maese-dake , 13, 16 & 19 Oct 1999, Y. Nakatani ( NIAES) ; 1♂, same locality, 2–3 Feb 2001, Y. Nakatani ( NIAES) ; 1♀, Itona , 22 Feb 2002, Y. Nakatani ( NIAES) ; 1♂ 2♀, Takeda , 12 Mar 2004, 24°24′11″N, 124°11′05 E, Y. Nakatani ( NIAES) ; 2♂ 3♀, Takeda-rindo , 18–19 Mar 2012, 24°24′38″N, 124°11′08″E, Y. Nakatani ( NIAES) ; 2♀, same locality, 16 Mar 2013, Y. Nakatani ( NIAES) ; 1♂, Mt. Yarabu-dake , 17 Mar 2012, 24°26′26″N, 124°05′25″E, Y. Nakatani ( NIAES) ; 1♂, same data except for data 20 Mar 2012 ( NIAES) ; 1♂, Ishigaki Is., Sukubaru Dam-side , 17 May 2008, 24°25′47″N, 124°12′42, Y. Nakatani ( NIAES) ; 1♂, Sokobaru Damside , 17 Mar 2012, 24°25′50″N, 124°12′42″E, Y. Nakatani ; 1♀, Sakieda, Mt. Yarabu-dake , 17 Jun 2013, N24°26′26, 124°05′26″E, H. Yoshitake ( NIAES) . Iriomote Island: 2♂, Fukari , 12 May 1993, M. Hayashi ( TYCN) ; 2♀, Funaura , UV light trap, 4 Jun 2013, T. Yasunaga ( TYCN) ; 1♀, same locality, 18 Oct 1998, at light, Y. Sawada ( NIAES) ; 2♀, Haemida Coast , on Fraxinus griffithii , 6 Jun 2013, T. Yasunaga ( TYCN) ; 1♀, same locality, 11 May 1993, Y. Nakatani ( NIAES) ;1♂, without detailed locality, 21–22 Mar 1967, I. Hattori (NIAES); 1♀, Iriomote Is., Komi, 23 Oct 1994, Y. Nakatani ( NIAES) ; 3♂, Iriomote Is., Komi, 14 Mar 2013, N24°19′42, 123°53′57″E, Y. Nakatani ( NIAES) ; 5♂ 1♀, Iriomote Is., Komi, Airagawa River , 21 Mar 2007, 24°20′36″N, 123°54′40″E, Y. Nakatani ( NIAES) ; 3♂ 5♀, same locality, 13 Mar 2013 Y. Nakatani ( NIAES) ; 1♂ 1♀, Iriomote Is., Otomi, Monbanare , 22 Mar 2007, 24°17′51″N, 123°52′26″E, Y. Nakatani ( NIAES) ; 3♂ 1♀, same data except for date 15 Jun 2008, Y. Nakatani ( NIAES) ; 1♂ 2♀, Otomi, Nishifunatsukihashi , 24°18′10″N, 123°51′34″E, 15 Mar 2013, Y. Nakatani ( NIAES) ; 1♀, Shirahama , 24°21′54″N, 123°45′17″E, 12 Mar 2013, Y. Nakatani ( NIAES) ; 2♂ 1♀, same locality, 8– 9 Apr 1997, H. Yoshitake ( TYCN) ; 1♀, same locality, 20 Jun 1998, C. Ishikawa ( TYCN) ; 1♀, without further locality, 19 Oct 1994, M. Takai (TYCN). TAIWAN: 1♂, Nantou County, Yuchi, TFRI Lienhuachi Research Center , 29–30 Jun 2015, H. Yoshitake ( NIAES) ; 1♂ 5♀, Kaohsiung County, Maolin District, Shanping Forest Ecological Garden, 22°58'20"N 120°40'44"E, 16–17 Oct 2015, Y. Nakatani , 1♂ with USIs (AMNH_PBI 00380486) (TFRI, NIAES); 1♂ 1♀, same data, except for collector H. Yoshitake ( NIAES) ; 1♂, same data, except for date 19 Oct. 2015, Light Trap ( NIAES) ; 2♂ 1♀, Kaohsiung County, Liouguei District, Zhong-Xing-Long Li, near Mt. Taiyuanshan , 22°59'22"N 120°40'44"E, 19 Oct. 2015, H. Yoshitake & Y. Nakatani ( NIAES) ; 2♂, Pingtung, Hengchun, Manzhou Gangkou , 21°59'35"N 120°50'42"E, 14 Oct 2015, Y. Nakatani ( NIAES) ; 1♂ 2♀, Pintung County, Kenting Park , 13 May 2004, C.S. Lin (1♂, genitalia dissected, misidentified as E. sauteri , NMNS) ; 1♀, Ilan County, Fushan , mercury light, 9 Jun 2004, W.T. Yang ( NMNS) .

Figures

FIGURE 1. Habitus images of Eurystylus species. A. Male adult from Chitwan, Nepal, identical to E. jingfui n. sp. B – C. E. ryukyus n. sp., female on Fraxinus griffithii. D. E. sauteri, female on Solidago canadensis, with Taylorilygus apicalis (Fieber) (upper) and Nysius plebeius Distant (middle). E – G. Ditto, male (E, G) and female (F) on Ligustorum japonicum. H, Ditto, head (velvety spots arrowed).

FIGURE 2. Habitus images of adult females and final-instar nymph (B – D) of Eurystylus species. A – B. E. coelestialium (image courtesy of M. Takai). C. E. sauteri Poppius. D. E. ryukyus n. sp. E. E. burmanicus from Chitwan, Nepal. F. E. costalis from Kathmandu Valley, Nepal.

FIGURE 4. Pygophore (A), left paramere (B, D, F, H, J) and right paramere (C, E, G, I, K) of Eurystylus species. A – C. E. ryukyus n. sp. D – I. E. sauteri. J – K. E. jingfui n. sp.

FIGURE 5. Endosoma and adjacent structures of Eurystylus species. A – C. E. ryukyus n. sp. D – G. E. sauteri Poppius. H. E. jingfui n. sp. I – J. E. coelestialium. Scale bars 0.2 mm.

FIGURE 6. Female genitalia of Eurystylus ryukyus n. sp. (A – B) and E. sauteri (C – D). A & C. Bursa copulatrix in dorsal view. B & D. Posterior wall.

FIGURE 7. Map showing the distributions of three closely related Eurystylus species; records (provincial levels) in continental China based upon Zheng et al. (2004).

FIGURE 8. Habitus images of dry-preserved specimens. A. Eurystylus coelestialium, lectotype male (upper) and paralectotype female mounted together (in 1998, MZHF). B. Male det. as E. luteus by Josifov from Pyongyang, North Korea (MZHF). C. E. sauteri, holotype female. D. Eurystylomorpha crassicornis, holotype male (Taiwan). E – F. Ditto, females in dorsal (E) and ventral (F) view. G. Ditto, scent efferent system. H. Eurystylopsis clavicornis, female from Kirtipur, Nepal (ventral view). I. Ditto, male. Scale bars 2 mm. Images (C & D) courtesy of J. F. Tsai and NMNS.

Tables

TABLE 2. Measurements for Eurystylus sauteri and E. ryukyus n. sp.

Locality	Sex	Total body length	Width head across eyes	Width vertex	Length labium	Lengths antennal segments I II III IV	Length pronotum incl. collar	Width basal pronotum	Width across hemelytron	Lengths hind femur tibia	leg tarsus
JA, Kyushu JA, Kyushu JA, Honshu Poppius Taiwan Taiwan Taiwan sauteri Mean (SD). E JA, Honshu JA, Kyushu JA, Kyushu Taiwan Taiwan Taiwan Mean (SD)	M M M M M M F F F F F F	4.05 5.76 5.63 4.43 5.38 6.30 5.26 (0.85) 5.88 4.50 6.15 5.55 5.40 6.33 5.64 (0.60)	0.99 1.14 1.12 1.08 1.15 1.10 1.10 (0.06) 1.12 0.99 1.14 1.06 1.08 1.21 1.10 (0.07)	0.38 0.42 0.46 0.43 0.45 0.41 0.42 (0.03) 0.48 0.42 0.44 0.40 0.47 0.50 0.45 (0.04)	0.25 0.23 0.24 0.24 0.24 0.25 0.24 (0.01) 1.90 1.82 1.94 1.71 1.92 2.09 1.90 (0.12)	0.82 1.75 0.55 0.49 1.05 2.28 0.61 0.44 1.08 2.20 0.64 0.47 1.02 2.09 0.64 0.59 1.07 2.22 0.68 0.57 0.95 2.28 0.63 0.53 1.00 2.14 0.62 0.52 (0.10) (0.20) (0.04) (0.06) 1.16 2.12 0.62 0.54 0.95 1.90 0.57 0.48 1.10 2.34 0.59 0.40 0.95 1.96 0.57 0.49 1.06 2.07 0.66 0.58 1.24 2.40 0.68 0.56 1.08 2.13 0.61 0.51 (0.11) (0.18) (0.04) (0.06)	1.16 1.60 1.55 1.36 1.64 1.54 1.47 (0.18) 1.48 1.27 1.60 1.52 1.40 1.80 1.51 (0.16)	1.63 2.24 2.20 1.84 2.22 2.09 2.04 (0.25) 2.21 1.75 2.30 1.98 1.96 2.45 2.11 (0.24)	1.96 2.53 2.56 2.09 2.47 2.53 2.36 (0.26) 2.64 2.07 2.66 2.47 2.33 2.83 2.50 (0.25)	1.71 2.19 2.28 2.70 2.21 2.67 1.98 2.46 2.30 2.71 2.09 2.76 2.10 2.58 (0.22) (0.22) 2.17 2.76 2.05 2.47 2.28 2.85 2.09 2.39 2.05 2.62 2.40 2.95 2.17 2.67 (0.13) (0.20)	0.49 0.53 0.54 0.55 0.55 0.55 0.54 (0.02) 0.55 0.53 0.57 0.57 0.57 0.59 0.56 (0.02)
JA, Okinawa JA, Amami Taiwan. sp Taiwan. Mean ryukyusn (SD) JA, Iriomote JA, Okinawa. Taiwan E Taiwan Mean (SD)	M M M M F F F F	4.29 6.00 4.67 5.00 4.99 (0.63) 4.50 6.30 5.53 4.95 5.32 (0.67)	1.05 1.06 1.04 1.09 1.06 (0.02) 0.99 1.14 1.12 1.11 1.09 (0.06)	0.38 0.40 0.43 0.45 0.41 (0.03) 0.42 0.44 0.49 0.48 0.46 (0.03)	1.52 1.71 1.86 1.84 1.73 (0.14) 1.71 2.05 2.07 2.00 1.96 (0.15)	0.95 2.00 0.55 0.48 1.05 2.20 0.57 0.49 1.08 2.14 0.64 0.57 1.12 2.03 0.64 0.54 1.05 2.09 0.60 0.52 (0.06) (0.08) (0.04) (0.04) 1.05 1.86 0.53 0.49 1.14 2.09 0.63 0.57 1.23 2.09 0.65 0.52 1.20 2.06 0.68 0.60 1.15 2.03 0.62 0.55 (0.07) (0.10) (0.06) (0.04)	1.33 1.52 1.31 1.43 1.40 (0.08) 1.20 1.67 1.56 1.48 1.48 (0.18)	1.86 2.00 1.79 1.92 1.89 (0.08) 1.77 2.22 2.13 2.08 2.05 (0.17)	2.09 2.47 2.09 2.29 2.24 (0.16) 2.09 2.72 2.49 2.48 2.44 (0.23)	1.90 2.47 2.15 2.66 2.02 2.53 2.08 2.58 2.04 2.56 (0.09) (0.07) 1.90 2.38 2.28 2.81 2.24 2.72 2.14 2.60 2.14 2.63 (0.15) (0.16)	0.53 0.57 0.52 0.51 0.53 (0.02) 0.51 0.57 0.56 0.55 0.55 (0.02)