Orius (Heterorius) hibiscus, 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 : 124

Orius (Heterorius) hibiscus sp. n.

( Figs. 1 C–D, 2A–F, 3, 4H–L)

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Diagnosis Recognized by its significantly smaller size (cf. Fig. 2B vs. 2G) and short appendages, with total body length <1.6 mm (♂) / <1.8 mm (♀) and with metatibia shorter than 0.5 mm; rather polished pronotum with sparsely distributed punctures and vestiture; disk-like paramere similar in general shape to that of O. strigicollis but lacking apical hook of denticule ( Fig. 4I, K ); and short and stout copulatory tube (Fig. 2E–F), in addition to unique, cryptic habitat in flower bud or bract of Hibiscus tiliaceus ( Fig. 1B ). A combination of these characters enables O. hibiscus to be distinguished from any other congeners belonging to the subgenus Heterorius (see also discussion below).

Description. Holotype male: Macropterous. Body generally castaneous to chocolate brown, tiny, oval, less than 1.8 mm in total length; dorsal surface rather polished, shining, with sparsely distributed, pale, simple, reclining setae. Head shiny fuscous, weakly porrect. Antenna yellowish brown; segment II thickened, about as thick as segment I, shorter than head width across compound eyes; segment IV reddish brown. Pronotum rather shiny, trapezoidal, sparsely and minutely punctate posterior to calli ( Fig. 3B ), somewhat squared at humeral angles, with a small, rounded hump behind each posterolateral corner of calli ( Fig. 3A ), without corner seta; scutellum uniformly shiny dark brown, flat; pleura dark brown; metathoracic scent efferent system (peritreme and evaporatorium) as in Fig. 3D , F–G, with almost parallel peritreme. Hemelytron shiny pale castaneous with chocolate brown posterior half including cuneus (cf. Fig 1C ); membrane pale grayish or smoky brown, semitransparent. All coxae shiny chocolate brown; legs pale brown; basal half of metafemur darkened; protibial teeth reddish brown; protibial grooming comb rather long ( Fig. 3H ); pretarsal structures as in Fig. 3H, N, O . Abdomen wholly shiny dark brown, generally elongate (Fig. 2D). Male genitalia (Figs. 2C, 4H–K): Paramere disk-like ( Fig. 4H ); conus tapered apically; denticule with its apex smooth and lacking apical hook ( Fig. 4 I–K) that is possessed by both O. minutus ( Fig. 4O ) and O. strigicollis ( Fig. 4E ); flagellum slightly longer than conus.

Female: Macropterous. Similar in general coloration and shape to male, but body larger and wider ( Fig. 1C ), antenna slender, pronotum tumid (Fig. 2D) and metafemur almost uniformly darkened ( Fig. 1D ). Female genitalia (Figs. 2E–F): Copulatory tube with basal segment short, rather stout, slightly shorter than apical segment (Fig. 2E). Sharp notches on ovipositor (gonapophysis I) generally small ( Fig. 4L ).

Measurements. Holotype male: Total length of body 1.56; head width across compound eyes 0.37; lengths of antennal segments I–IV 0.08, 0.23, 0.16, 0.19; basal width of pronotum 0.68; maximum width across hemelytron 0.73; and lengths of metafemur, tibia and tarsus 0.40, 0.48, 0.14. Females (n=3): Total length of body 1.68–1.80; head width across compound eyes 0.35–0.36; lengths of antennal segments I–IV 0.08–0.10, 0.18–0.19, 0.16–0.18, 0.19–0.20; basal width of pronotum 0.67–0.69; maximum width across hemelytron 0.79–0.81; and lengths of metafemur, tibia and tarsus 0.47–0.48, 0.47–0.49, 0.13–0.16.

Etymology. Named for its plant association, Hibiscus tiliaceus L.; the generic name (from Latin, masculine noun) of hibiscus broadleaf trees.

Distribution. Japan (Ryukyus: Okinawa Island).

Biology. This unique new species was confirmed to prefer concealed habitats, or the insides of flower bud and bract of Hibiscus tiliaceus L. ( Malvaceae ) ( Fig. 1A, B ) planted along streets and public gardens near seaports in Naha City, Okinawa Island.

Holotype: ♂, JAPAN: Ryukyus, Okinawa Island, Naha City , Nishi-machi (western coastal area), 26°13'N 127°40'E, Hibiscus tiliaceus (hand collecting, along streets), 17 Jun 2018, T. Yasunaga ( TKPM) ( AMNH _ PBI 00380646 ) ; Paratypes. JAPAN: Same data as for holotype, 6♀ ( AMNH, NIAES, TYCN) ; Okinawa Island, Naha City, Minato-machi , Aja New Port (Garden), 26°14'29.2"N 127°40'41.8"E, Hibiscus tiliaceus, 16–17 Jun 2018, T. Yasunaga, 2♀ ( TYCN) (1♀ with USI, AMNH _ PBI 00380647 ) .

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 3. Scanning electron micrographs for holotype male (A–I) and female (J–O) of Orius hibiscus sp. nov. A. Head and pronotum, anterior view. B & J. Ditto, dorsal view (arrows indicating paired micro-warts). C & K. Head and thorax, left lateral view. D & L. Thoracic pleura, left lateral view. E. Dorsal vestiture pattern. F, G & M. Scent efferent system. H. Protarsus. N. Mesotarsus. O. Metatarsus.

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.