Eurystylus yixuanae, Yasunaga & Yamada & Tsai, 2023

Yasunaga, Tomohide, Yamada, Kazutaka & Tsai, Jing-Fu, 2023, New genera and new species of remarkably large-sized or uniquely-shaped mirine plant bugs from Taiwan (Heteroptera: Miridae: Mirinae), Zootaxa 5278 (2), pp. 264-288 : 269

Eurystylus yixuanae n. sp.

( Figs. 1A–B , 2 E−F, 5A−H, 10A−G, 14A−D)

Diagnosis: Recognized readily by its yellow-green basic coloration; wide, tumid body shape; uniformly pale head that lacks black, velvety macula on frons; and yellowish pronotum with a pair of dark ocellate spots. These unique characters enable this new species to be distinguished from any known congeners.

Description. Male: Body ovoid, boxlike, stout; general coloration yellow green, partly pale olive green ( Fig. 1A–B ); dorsum more or less shining, with uniformly distributed, sericeous, reclining setae and sparsely distributed, simple, semierect setae ( Fig. 10B ). Head pale olive green, shining, lacking fuscous, clustered micro-pilosity on frons; eye small; vertex wide. Antenna dark brown, partly tinged with red, generally thick; segment I pale olive brown, except for darkened apex; basal 2/3 of segment II pale reddish brown; extreme bases of segments III and IV pale. Labium pale reddish brown, reaching but not exceeding apex of mesocoxa; apical half of segment IV darkened. Pronotum shining, with a pair of dark, circular spots on disk and smoky brown posterior margin; mesoscutum reddish brown; scutellum yellowish brown, usually widely brownish medially; thoracic pleura yellowish brown; scent efferent system as in Fig.10C . Hemelytron dark brown, strongly declivous at cuneal fracture; exocorium (embolium) and basal half of cuneus yellowish brown; membrane pale smoky brown, semitransparent, with dark brown veins. All coxae and legs yellowish brown; apical half of each tarsomere III darkened; pretarsal structure as in Fig. 10F . Abdomen uniformly yellowish brown. Male genitalia ( Fig. 5A–C ): Left paramere C-shaped, with inflated hypophysis ( Fig. 5A ); right paramere straight, with small hypophysis ( Fig. 5B ); vesica with four lobal-sclerites as in Fig. 5C (terminology of the sclerites sensu Yasunaga et al., 2017).

Female: Almost similar to male in overall appearance and biometrics; body slightly larger and stouter; scutellum not widely darkened, with three brown stripes ( Fig. 1A ). Female genitalia ( Figs. 5D–H , 14A–D ): sclerotized rings small, thick-rimmed, situated near lateral margins of genital chamber ( Fig. 5D–F ); posterior wall with small, rounded dorsal structure ( Fig. 5H ); interramal sclerite semi-circularly widened, densely covered with spinules ( Fig. 14B–C ).

Measurements. See Table 1 .

Etymology. Named after Ms. Yi-Xuan Hsieh who kindly provided a specimen as well as some images of live individuals of this new species for this study; a noun in genitive case.

Distribution. Taiwan (Kaohsiung, Pingtung).

Biology. Unknown.

Type material. Holotype (♁), TAIWAN: Pingdung (Pingtung) Co., Siangjao Bay , 21°55'42.7''N, 120°49'40.2''E, UV lighting, Y.-C. Lan & Y.-H. Peng, 27 May 2011 ( AMNH _ PBI 00380763 ) ( NMNS) . Paratypes. TAIWAN: 1♁ 1♀, same data as for holotype ( NMNS) ; 1♀, Kaohsiung, Mt. Zhongliao-shan , 22°49'48"N 120°25'57"E, 30 May 2013, Y. X. Hsieh ( TYCN) .

Figures

FIGURE 1. Habitus images of live individuals of mirine plant bugs known from Taiwan. A–B. Eurystylus yixuanae n. sp., female (courtesy of Y.X. Hsieh). C. E. sauteri (Poppius), female. D. Same, head. E. E. ryukyus (Yasunaga, Nakatani & Chérot), male. F. Rhopalimiris gagai n. sp., male (courtesy of I. S. Lin).

FIGURE 2. Habitus images of dry-preserved specimens of mirine plant bugs.A. Eocalocoris gotohi n. sp., female, dorsal view. B. Same, ventral view. C. Eo. hirashimai Miyamoto & Yasunaga, male (from Kyushu, Japan). D. Eo. albicerus Yasunaga & Takai, male (from Shikoku, Japan). E. Eurystylus yixuanae n. sp., holotype male. F. Same, left lateral view.

FIGURE 5. Male (A–C) and female (D–H) genitalia of Eurystylus yixuanae n. sp. A. Left paramere. B. Right paramere. C. Vesica. D. Genital chamber, dorsal view. E. Same, ventral view. F. Sclerotized rings and adjacent structures. G. Ovipositor (gonapophysis) I. H. Posterior wall. Scale bars 0.1 mm. Abbreviations: FL, fourth lobal sclerite; ML, median lobal sclerite; TL, third lobal sclerite (sensu Yasunaga et al. 2017).

FIGURE 10. Scanning electron micrographs for Eurystylus yixuanae n. sp., E. coelestialium (Kirkaldy, 1902), male (H, M) and female (N), E. sauteri (Poppius), male (I, O) and E. ryukyus (Yasunaga, Nakatani & Chérot), male (K–L). A, J. Anterior body, left lateral view. B. Anterior forewing, left lateral view. C. Scent efferent system. D, M. Genital segment, left lateral view. E. Matatarsus. F. Pretarsal structure of mesoleg. G. Protarsus. H–I, Metatarsus. K–L, N–O. Field of eye-black micro-setae along inner margin of eye on frons.

FIGURE 14. Scanning electron micrographs of female genitalia for Eurystylus yixuanae n. sp. (A–D), E. coelestialium (Kirkaldy, 1902) (E–G) and Taiwanocapsus luteocordatus n. sp. A, E, H. Genital chamber, dorsal view. B, F, J–K. Posterior wall. C, G, L. Interramal lobe. D, I. Ovipositor (gonapophysis) I.