Eurystylus sauteri Poppius

Figs 1 D–H, 2C, 3A–D, 4D–I, 5D–G, 6C–D, 7, 8C, Tables 1–2

Eurystylus sauteri Poppius, 1915: 15 (n. sp., TAIWAN: Kosempo; images of the holotype as in Fig. 7 A); Kawasawa & Kawamura, 1975: 162, fig. 129 (diag.); Schuh, 1995: 769 (cat.); Kerzhner & Josifov, 1999: 100 (cat.); Zheng et al., 2004: 277 (diag.); Schuh (2002–2014) online catalog.

Eurystylus luteus: Yasunaga et al., 1999: 6 (list); Yasunaga, 2001: 233 (not Hsiao, 1941). Eurystylus sp. Yasunaga et al., 1993: 158 (diag.).

Diagnosis. General coloration and external morphology as in E. ryukyus, from which E. sauteri can be distinguished by the following characters: Pale or creamy white base of antennal segment III; obscure, elongate ovoid paired spots on pronotum (spots obliterated in some individuals); strongly and sharply expanded hypophysis of left paramere (Fig. 4 D, F, H); medially protruded sensory lobe of L-shaped right paramere (Fig. 4 E, G, I); wholly spinulate primary lobe of endosoma (Fig. 5 D–G); larger sclerotized ring (Fig. 6 C); and narrower interramal lobe (Fig. 6 D). Significant intraspecific variation recognized in general coloration (Figs 1 E–F, 3A–D) and size (Table 2). Final-instar nymph (Fig. 2 C) recognized by its pale brown body largely mottled with reddish spots; reddish brown apical half of antennal segment II; largely reddish brown pronotum with a pair of small, obscured ocellate spots; and a few pairs of ocellate spots on abdominal sterna.

Description. Male: Body generally yellow or grayish brown, sometimes largely darkened; dorsal surface matte, mottled with pale or grayish brown spots, with three types of vestiture similar to E. ryukyus . Head yellowish, grayish or dark brown, with clear fuscous, velvety spot on anterolateral margin of frons. Antenna dark brown; segments I and basal half of segment II reddish brown; bases of segments II, III and IV white. Labium pale brown, reaching but not exceeding apex of mesocoxa; segments III and IV shiny chocolate brown. Paired spots on pronotal disk obscured, narrowed, or sometimes obliterated; posterior inner margin of each callus narrowly infuscate; scutellum usually darkened medially and/or apically; pleura grayish to dark brown, matte, with uniformly distributed, silvery, scalelike setae; scent efferent system pale grayish brown. Hemelytron yellowish brown, grayish brown or largely darkened; cuneus dark brown, narrowly yellow-orange at middle; membrane pale smoky brown, narrowly semitransparent at middle, with fuscous veins. Coxae and legs pale grayish or yellowish brown; each coxa partly darkened; all femora usually dark brown, mottled with minute pale spots; base of each femur more or less pale; subapical part of metafemur usually with a pale ring or annulation; all tibiae brown or dark brown, sometimes tinged with red; each tibiae usually with a pale ring at middle. Abdomen grayish brown or darker, with small dark spots at spiracles, with uniformly distributed, silvery, short, reclining setae. Male genitalia (Figs. 4 D–I, 5D–G): Parameres large in size; left paramere C-shaped, with noticeably expanded hypophysis (extent of width somewhat varying as in Fig. 4 D, F, H); right paramere L-shaped, medially with protruded sensory lobe (Fig. 4 E, G, I); endosomal PL almost straight, wholly spinulate on dorsal side, terminated in a hook; TL narrowed, not much developed (Fig. 5 D–G). Female: As in male and original description by Poppius (1915). Female genitalia (Fig. 6 C– D): Generally large in size; sclerotized ring thick-rimmed, ovoid (Fig. 6 C); posterior wall with narrow interramal lobe and lanceolate dorsal structure (Fig. 6 D).

Measurements. See Table 2.

Biology. This species predominantly inhabits warm temperate zones and is associated with various inflorescences of dicot angiosperms (Table 1). The immature forms have been found from those of six plant families. A bivoltine life cycle is assumed, based on available collection data. In southwestern Japan, the adults appear in June and are almost continuously collected until late October.

Discussion. Kawasawa & Kawamura (1975) first reported E. sauteri from Japan (Shikoku and Kyushu). Subsequently, Miyamoto & Yasunaga (1989) considered E. sauteri was restricted to Ryukyus and Taiwan [species (x) in Discussion of E. ryukyus above], and Yasunaga et al. (1999) assigned the species occurring in Honshu, Shikoku and Kyushu [species (y)] to E. luteus Hsiao. As mentioned above, there is a strong likelihood that E. luteus and E. sauteri are conspecific, based on available evidence. We recognize the appropriate treatment of Kawasawa & Kawamura (1975), using the name sauteri for the species (y).

Within the Ryukyus, E. sauteri is yet to be confirmed but E. ryukyus is abundant. These two species coexist in Taiwan and southernmost parts of Kyushu and Shikoku (Fig. 7). We currently cannot elucidate why E. sauteri does not inhabit the subtropical islands. Incidentally, three female specimens from Shan District of N. Myanmar (TYCN) most probably represent E. sauteri, which is now assumed to widespread over eastern Asia.

Material examined. Holotype Ƌ, TAIWAN: Kaohsiung City, Kosempo [= current Kahsian, 23.07, 120.60], 7 Sep 1909, H. Sauter (without USIs, image examined, Fig. 8 C). Additional material. More than 150 specimens (CNC, NIAES, TYCN) collected between Jun 5 and Oct 16 from the following localities . JAPAN: Honshu: Shizuoka Pref., Atami City; Wakayama Pref., Shirahama Town, Katsuragi Town, Nachi Katsu’ura Town & Tanabe City— 1♂ from Tanabe City ( Yasukawa Valley) with USIs (AMNH _PBI 00380482) ; Hyogo Pref., Inagawa, Izushi. Shikoku: Ehime Pref., Omogo . Kochi Pref., Kami City, Kochi City, Nankoku City, Sukumo City & Tsuno Town (Tengu Plateau). Kyushu : Fukuoka Pref., Fukuoka City (Aburayama & Nokonoshima Island); Miyazaki Pref., Miyazaki City (Sadobaru); Nagasaki Pref., Isahaya City ( Mt. Gokahara) , Nagasaki City (Kabashima Island, Nameshi, Nishiumi & Taira), Saikai City (Seihi Town, Nagasaki Biopark), Tsushima Island (Kechi) & Unzen City ( Azuma Town) — 1♂ from Unzen City, Azuma (32.81, 130.25) with USIs. (AMNH _PBI 00380481); Oita Pref., Shonai. TAIWAN: 2♂ 1♀, Nantou County, Puli, Shizitou (23.99, 121.03), 15–18 May 1989, S. Gotoh (TYCN), 1♂ with USIs (AMNH _PBI 00380483) ; 1♀, Nantou, Yuchi, TFRI Lienhuachi Research Center, 29–30 Jun 2015, H. Yoshitake (NIAES) ; 1♂ 2♀, Nantou, Ren-ai, Mt. Kuantaoshan, 1 Jul 2015, H. Yoshitake (NIAES) ; 2♀, Nantou, Hweishun, 20 Feb 1990, C.S. Tsung, light trap (NMNS) ; 1♂, Nantou, Jenai, Chunyang, mercury light, 10–12 Aug 1998, C.S. Lin & W.T. Yang (NMNS) ; 1♀, Ilan County, Fushan Botanical Garden, 27–28 Jun 2015, H. Yoshitake (NIAES) ; 1♀, Fushan, mercury light, 9 Jun 2004, W.T. Yang (NMNS) ; 3♂ 2♀, Kaohsiung County, Maolin District, Shanping Forest Ecological Garden, 22°58'20"N 120°40'44"E, 16–17 Oct 2015, Y. Nakatani (NIAES) ; 2♂ 1♀, same locality, 19 Oct. 2015, Light Trap, H. Yoshitake (NIAES); 4♂ 4♀, 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) ; 1♀, Taichung County, Wanfeng Hill, Malaise trap, Sep 1984, K.S. Lin & K.C. Chou (NMNS)