Orius, Yasunaga, 2019

Yasunaga, Tomohide, 2019, A new species of the flower bug genus Orius Wolff (Hemiptera: Anthocoridae) cryptically inhabiting Hibiscus tiliaceus L. (Malvaceae), Zootaxa 4629 (1), pp. 122-132 : 130

Key to Japanese species of Orius

1. Pronotum with four (anterior + posterior) corner setae ( Fig. 5G )................................................ 2

- Pronotum with either anterior or posterior corner setae, or lacking any........................................... 4

2. Hemelytron uniformly shiny fuscous; flagellum bifurcate................................... O. (Trichorius) atratus

- Hemelytron almost entirely pale brown, with cuneus sometimes narrowly darkened; flagellum simple, not branched....... 3

3. Pronotum wide, not much polished, densely setose, with wide collar area, narrow callus and angulate anterolateral corner; inhabiting a deciduous oak, Quercus accutissima in Honshu and Kyushu. ..................... O. (Xylorius) miyamotoi

- Pronotum trapezoidal, highly polished, almost impunctate and sparsely setose, with narrower collar area, wide callus and rather rounded anterior corner; inhabiting a fabaceous vine, Pueraria montana on Okinawa Island of Ryukyus...... O. (O.) takaii

4. Dorsal vestiture very short; pronotal callus flat, distinctly and deeply punctate; hemelytron uniformly pale yellow, semitransparent.......................................................................... O. (Dimorphella) tantillus

- Dorsum with noticeable setae; callus more or less inflated, with sparse and fine punctures; hemelytron pale brown; cuneus usually with darkened (at least) apical part (often uniformly dark brown in O. hibiscus and O. strigicollis )............................................................................................. 5, species of subgen. Heterorius

5. Body obviously tiny, with total length <1.6 mm (♂) / <1.8 mm (♀); legs generally short, with metatibia shorter than 0.5 mm ........................................................................... O. (Heterorius) hibiscus sp. n.

- Body moderate in size, longer than 1.7 mm (♂) / 1.9 mm (♀); legs long, with metatibia longer than 0.5 mm (usually 0.6–0.7 mm)................................................................................................ 6

6. Head bicolorous, fuscous with yellow or yellow-brown clypeus; pronotum oily shiny, with noticeable anterior corner seta ( Fig. 5A ), and very sparsely distributed punctures and setae; pronotal callus widened and flattened; all legs uniformly yellow............................................................................................. O. (H.) nagaii

- Head uniformly fuscous; pronotum weakly shining, with distinct punctures and semierect setae but lacking corner seta ( Fig. 5D ); pronotal callus narrow, more or less inflated; femora and/or tibiae usually partly or widely darkened............... 7

7. Metafemur entirely pale, or if metafemur darkened, then its apex and entire metatibia also fuscous; paramere with slender, stout conus and short flagellum ( Fig. 5F ); copulatory tube short, tiny (<0.05 mm), without apical segment........ O. (H.) sauteri

- Metafemur usually dark, always with pale apex; metatibia sometimes darkened except for base and apex; paramere with wide and disk-like conus and long flagellum ( Figs. 4D, O ); copulatory tube ≥ 0.1 mm, with both apical and basal segments elongate as in Fig. 2H........................................................................................ 8

8. Cuneus (usually at least its apical half) infuscate, well contrasting to yellowish corium (cf. Fig. 1F ); paramere with small denticule removed from base of flagellum ( Fig. 4E ); basal segment of copulatory tube expanded at apex.... O. (H.) strigicollis

- Cuneus entirely pale, or darkened at apex; paramere with large denticule contiguous to base of flagellum ( Fig. 4O ); basal segment of copulatory tube slender and linear..................................................... O. (H.) minutus

Figures

FIGURE 1. Habitat (A–B) and habitus images for Orius hibiscus sp. nov. (C–D) and O. strigicollis (Poppius) (E–F). A & B. Hibiscus tiliaceus L. planted at a park in Naha City yielded O. hibiscus. C & D. O. hibiscus, female (Naha City). E. O. strigicollis, male (Nagasaki, Japan). F. Same, female (Majuro Atoll, Republic of Marshall Islands, possibly introduced with nursery stock from Taiwan).

FIGURE 4. Scanning electron micrographs for Orius strigicollis (A–G) (from Hahajima Island, Japan), O. hibiscus sp. nov. (H–L) and O. minutus (L.) (From Nagano, Japan) (M–O). A. Left lateral habitus of male. B, C & N. Scent efferent system of male. D, E, H–K & O. Paramere. F. Female head and thorax, dorsal view. G & L. Ovipositor (gonapophysis I). M. Male head and thorax, dorsal-left lateral view. Abbreviations: CN: conus; DT: denticule; and FG: flagellum.

FIGURE 5. Scanning electron micrographs for Orius nagaii Yasunaga (A–C) (from Tsushima Island, Japan), O. sauteri (Poppius) (D–F) (Nagasaki, Japan), an undescribed species of nominotypical subgenus Orius s. str. (G–H) (Nepal)., O. (Xylorius) sp. (L.) (I) (Nepal), Kitocoris hahajima Yasunaga, paratype female (J) (Hahajima Island, Japan), and K. omura Herring, male (K) (Chichijima Island, Japan) and Bilia japonica Carayon & Miyamoto, female (Okinawa, Japan) (L). A, D, G, J, K & L. Male and female (J, L) head and thorax, dorsal (A, D & L) and left lateral (G, J & K) views. B & E. Scent efferent system. C, F, H & I. Apical pygophore with paramere. Abbreviations: CN: conus; CS: corner setae; DT: denticule; and FG: flagellum.