Orius (Xylorius) paveli, Yasunaga & Yamada & Duwal, 2019

Yasunaga, Tomohide, Yamada, Kazutaka & Duwal, Ram Keshari, 2019, Three new species of the flower bug genus Orius (Hemiptera: Heteroptera: Anthocoridae) from Nepal, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (2), pp. 391-401 : 398

Orius (Xylorius) paveli sp. nov.

( Figs 5–6 , 10 , 15–16, 19–20 , 46–60 , 64–65 )

Type material. HOLOTYPE: ♁, NEPAL: RASUWA DIST.: Langtang Himal National Park, Lama Hotel , 2,500 m alt., 28°09′43″N 85°25′49″E, leaves and stems of Urtica (prob.) dioica L., 8 June 2016, T.Yasunaga ( NMTU) (AMNH_PBI 00380640). PARATYPES: NEPAL: RASUWA DIST.: Langtang Himal National Park, same data as for holotype, 2 ♁♁ 16 ♀♀ ( AMNH, TKPM, TYCN); Syabru Besi~Bamboo, 28°09′56″N 85°20′34″E ~ 28°09′18″N 85°23′52″E, sweep-netting Urtica (prob.) dioica , 2 June 2006, T. Yasunaga, 2 ♁♁ 3 ♀♀ ( TYCN).

Differential diagnosis. Recognized by its chocolate brown general coloration; a distinct spine on posterior margin of episternum ( Fig. 50 ); developed evaporative area widely occupying metathoracic scent efferent system ( Figs 51, 54 ); dark femora with pale apices ( Figs 5–6 ); unique shape of pygophore (with a bundle of remarkable spines as in Figs 19 , 59 , 64 ); long flagellum of paramere ( Figs 59 , 64 ); and subapically inflated, gourd-like copulatory tube with a bottle-lid-shaped apex ( Figs 20 , 65 ). Externally similar to species of the subgenus Trichorius ; this new species can be distinguished by reduced corner seta at posterior angle of pronotum, presence of a spine on the episternum, developed evaporative area of the scent efferent system, and long flagellum of the paramere. Orius paveli is easily distinguished from O. (X.) miyamotoi Yasunaga, 1997 by the totally chocolate brown dorsum, reduced posterior corner setae on the pronotum and long flagellum of the paramere.

Description. Male. Macropterous. Body generally chocolate brown, oval and slightly elongate, small to moderate in size; dorsal surface moderately shining, with uniformly distributed pale, simple, semierect setae. Head shiny reddish brown, sometimes yellowish or paler brow in some specimens.Antenna dark brown, not thickened throughout; whole segment II and base of segment III yellow; segment II about 2/3 as long as head width across compound eyes; segment IV often tinged with red. Labium shiny reddish brown, reaching but not exceeding apex of procoxa. Pronotum shiny fuscous, sparsely and roughly punctate posterior to calli, with weak corner seta at anterior angle (posterior corner seta reduced); scutellum uniformly shiny dark brown, flat; pleura dark brown, partly reddish; posterior margin of episternum with spine ( Fig. 53 ); metathoracic scent efferent system as in Figs 53–54 , widely occupied by evaporative area. Hemelytron chocolate brown, weakly shining; membrane smoky brown. Coxae dark brown; legs pale brown; all femora dark brown, except for each apex yellowish brown; protibial teeth rather developed ( Fig. 55 ); pretarsal structures as in Figs 56–57 . Abdomen shiny chocolate brown. Male genitalia ( Figs 19 , 58–60 , 64 ): Paramere disk-like, with folded process in middle, lacking denticule situated near base of flagellum ( Figs 28 , 64 ); conus tapered apically; flagellum very long, with thickened basal half.

Female. Macropterous. Similar in general coloration and shape to male; body ovoid, tumid; antenna slender and hemelytron not significantly infuscate. Female genitalia ( Figs 20 , 65 ): Copulatory tube subapically inflated, gourd-like, with bottle-lid-shaped apex.

Measurements (mm). Male (n = 4). Total length of body 1.66–1.68; head width across compound eyes 0.30–0.32; lengths of antennal segments I – 0.08–0.10, II – 0.21–0.23, III – 0.15–0.17, IV – 0.19–0.20; basal width of pronotum 0.67–0.69; maximum width across hemelytron 0.75–0.76; and lengths of metafemur 0.47–0.48, metatibia 0.51–0.56, and metatarsus 0.16–0.18.

Female (n = 3). Total length of body 1.50–1.62; head width across compound eyes 0.30–0.31; lengths of antennal segments I – 0.07–0.09, II – 0.19–0.20, III – 0.15–0.17, IV – 0.19–0.20; basal width of pronotum 0.66–0.74; maximum width across hemelytron 0.76–0.78; and lengths of metafemur 0.47–0.49, metatibia 0.48–0.51, and metatarsus 0.14–0.18.

Etymology. This new species is named in honor of the eminent Czech heteropterist, Prof. Pavel Štys, who regrettably passed away in August 2018; noun in genitive case standing in apposition.

Biology. This new species was confirmed to be associated with a stinging nettle, most similar to Urtica dioica L. ( Urticaceae ). Although its life cycle is unknown, Orius paveli was found on leaves and stems ( Fig. 10 ) covered with stinging hairs (secreting formic acid) causing skin irritation (cf. YOSHIDA 2005), which presumably provides O. paveli a secure habitat. On the same plant, an unidentified species of thrips (Thysanoptera) co-occurred with the anthocorid which is assumed to prey on the thrips.

Comments. Subgeneric position of Orius paveli is currently not well elucidated, although at first sight it is reminiscent of a member of Trichorius . Nonetheless, the preponderance of the current evidence (i.e. the male genital segment bearing a bundle of strong spines on its dorsal surface [ Figs 19 , 58–59 , 63 ] and similarity in shape of the female copulatory tube [ Figs 20 , 65 ]) argues in favor of the provisional placement of this new species in the subgenus Xylorius .

Figures

Figs 1–6. Habitus images of Nepalese Orius species, live individuals. 1–2 – O. ekaii sp. nov., ♁; 3–4 – O. nigromaritus sp. nov. (3 – holotype ♁, AMNH_PBI 00380639; 4 – ♀); 5–6 – O. paveli sp. nov. (5 – ♁; 6 – ♀).

Figs 7–12. Habitats of Nepalese Orius species. 7–8 – full blossom of Quercus semecarpifolia, on which O. ekaii sp. nov. was found, 9 – sweeping inflorescence of Q. semecarpifolia, 10 – Urtica dioica, with two adults of O. paveli sp. nov. (arrows), 11 – Chitwan National Park in southern Nepal, type locality of O. nigromaritus sp. nov., 12 – male flowers of Mallotus philippensis, considered to be breeding host of O. nigromaritus sp. nov.

Figs 13–21. Dorsal habitus (13–17), and male (18–19, 21) and female (20) genitalia of Nepalese Orius species. 13–14, 18 – O. nigromaritus sp. nov.: 13 – holotype ♁ (AMNH_PBI 00380639); 14 – ♀; 18 – pygophore with paramere. 15–16, 19–20 – O. paveli sp. nov.: 16 – holotype ♁; 17 – ♀; 19 – pygophore with paramere; 20 – female genital segments with copulatory tube, dorsal view. 17, 21 – O. ekaii sp. nov.: 17 – holotype ♁; 21 – pygophore with paramere. Scale bars: 0.5 mm for 13–17; 0.1 mm for 18–21.

Figs 46–60. Scanning electron micrographs of Orius paveli sp. nov. (46–51 – ♀; 52–60 – ♁). 46 – whole body, left lateral view, 47–49, 52 – anterior body, left lateral view, 50 – pleura, left lateral view, 51, 53–54 – metathoracic scent efferent system, 55 – protibia, 56 – protarsus, 57 – metatarsus, 58–59 – pygophore with paramere, 60 – conus and base of flagellum.

Figs 61–65. Male (61–62, 64) and female genitalia (63, 65) of Nepalese Orius species. 61 – O. ekaii sp. nov., 62–63 – O. nigromaritus sp. nov., 64–65 – O. paveli sp. nov.

Figs 22–33. Scanning electron micrographs of Orius ekaii sp. nov. (22–30, 33 – ♁; 31–32 – ♀). 22–23, 25 – anterior body, left lateral view; 24, 32–33 – metathoracic scent efferent system: 25 – protibia, 26 – protarsi, 27 – metatarsus; 28–29 – male genital segment with paramere, 30 – evaporative area of scent efferent system.