Prolygus nigriclavus ( Poppius, 1915 )

Yasunaga, Tomohide, Schwartz, Michael D. & Chérot, Frédéric, 2018, Review of the plant bug genus Prolygus and related mirine taxa from eastern Asia (Hemiptera: Heteroptera: Miridae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 58 (2), pp. 357-388 : 365

Prolygus nigriclavus ( Poppius, 1915)

( Figs 6–11 , 16–17 , 33–36 , 48 , 68 )

Lygus nigriclavus Poppius, 1915: 35 (original description).

Lygus nigriclavus: POPPIUS (1914) : 340 (key).

Dagbertus nigriclavus: MIYAMOTO (1975) :133 (new combination); SCHUH (1995): 752 (catalog).

Prolygus nigriclavus: SCHWARTZ & KERZHNER (1997) :255 (new combination); KERZHNER & JOSIFOV (1999): 172 (catalog); ZHENG et al. (2004): 561 (diagnosis, key).

Neolygus nigriscutellaris Lu & Zheng, 2004 in ZHENG et al. (2004): 414, 750 (original description). New synonymy.

Type material examined. Lygus nigriclavus : HOLOTYPE: ♀, TAIWAN: Chip-Chip [currently Nantou County, 23.83, 120.77] 9 Feb, H. Sauter ( HNHM, without USIs, examined by F. Chérot, Fig. 68 ).

Additional material examined. TAIWAN: KAGI: Tek-kia, 23.50, 120.69, 13 Apr 1965, S. Miyamoto, 1 ♁ ( TYCN) ( AMNH _PB I 00380499); Fenchihu, 10 Apr 1965, T. Shirozu, 1 ♀ ( TYCN). NANTOU: Huiseun Forest Area, forest trail no. 45 toward Guandao, 24°04 ′ 57.9 ″ N 121°01 ′ 54.9 ″ E, 1000–1200 m, 14 Mar 2017, T. Yasunaga ( TYCN). TAOYUAN: Tengihih National Forest Recreation Area, 23.06, 120.75, 12–13 May 1989, S. Gotoh, 2 ♁♁ 3 ♀♀ ( TYCN). INDONESIA: SUMATRA: Brastagi, North of Toba Lake, 3.18, 98.50, 1,400 m, UV light trap, 7 Dec 1989, T. Yasunaga, 1 ♁ ( TYCN) ( AMNH _PBI 00380500). MALAYSIA: PERAK: Taiping, Bukit Larut (Maxwell Hill), 4.8624, 100.7999, 1100 m, UV light trap, 6 Jan 1990, T.Yasunaga, 1 ♁ ( TYCN) ( AMNH _PBI 00380501). NEPAL: KATHMANDU VALLEY: Samakhusi, Gongabu, 27°43 ′ 59.5 ″ N, 85°18 ′ 49 ″ E, 1,300 m, UV light trap, 31 May 2005, T.Yasunaga, 1♀ ( TYCN) ( AMNH _PBI 00380502); Swayambhu, Natural History Museum Garden, 27°42 ′ 52.8 ″ N, 85°17 ′ 13.5 ″ E, 1,350 m, on inflorescence of Trema ? sp., 12 May 2006, T. Yasunaga, 1 ♁ 1 ♀ ( TYCN). KASKI: Pokhara, 4 Nov 2005, T. Yasunaga, 1 ♁ ( TYCN). RASUWA: Langtang Himal National Park, trekking path between Ghora Tabela and Lama Hotel, 28.18, 85.44, flowers of Cotoneaster affinis , 6 Jun 2006, T.Yasunaga, 1 ♁ (5th instar when collected; emerging on June 13) ( NMTU). THAILAND: CHIANG MAI: Doi Pui, 18.8, 98.8, 1,400 m, 15 May 2001, S. Sakurai, 4 ♀♀ ( TYCN).

Redescription. Detailed description of the holotype female ( Fig. 66 ) was provided by POPPIUS (1915) and is not repeated here. Male. Total length of body 3.47–3.65 mm, basically similar to female, but darker patterns on dorsum variable, particularly on pronotum and hemelytron (cf. Fig. 8 ) often extensive. COLOURATION: Body yellowish brown, elongate-oval, subparallel-sided; vertex uniformly pale ( Fig. 7 ), sometimes with a dark spot at middle ( Fig. 8 ); clypeus usually infuscate. Antenna dark brown, except for segment I pale brown. More than posterior third of pronotum and entire scutellum fuscous. Pronotum more or less darkened posteriorly (sometimes almost entirely fuscous), except for always pale posterior margin. Hemelytron shiny pale yellowish brown, somewhat tinged with green in fresh specimens; clavus, and inner margin of corium fuscous; base of clavus more or less keeled. Coxae and legs creamy yellow (fading to pale brown in dried specimens); metafemur pale reddish brown at apical half, with two obscure rings subapically; tibial spines pale brown; each tarsomere III darkened. Abdomen shiny fuscous; ventral median part largely yellow. SURFACE AND VESTITURE: Dorsal surface shining, with uniformly distributed, silky, semierect setae; head smooth; vertex faintly carinate basally. GENITALIA ( Figs 33–36 ): Pygophore with a weak, tiny PS ( Fig. 33 ). Left paramere ( Fig. 34 ) with rather tumid sensory lobe; hypophysis strongly protruded mesially, with a short process ventrally. Right paramere well developed, weakly curved at basal third, with a small, blunt-tipped hypophysis ( Fig. 35 ). Endosomal primary lobe sclerite horn-like; third lobe with a small, spinulate sclerite at apex; secondary gonopore small, thick-rimmed; seminal duct expanded subapically ( Fig. 36 ).

Measurements (in mm). ♁/ ♀: Total length of body 3.47–3.65 / 3.92; head width including eyes 0.88–0.89 / 0.87–0.88; vertex width 0.21 / 0.31–0.33; lengths of antennal segments I–IV 0.40, 1.29, 0.66, 0.44 / 0.45, 1.35, 0.77, 0.45; labial length 1.22 / 1.28; mesal length of pronotum including collar 0.70 / 0.77; basal width of pronotum 1.20 / 1.35; maximum width across hemelytron 1.25–1.32 / 1.47–1.50; and lengths of metafemur, tibia and tarsus 1.28, 1.92, 0.47 / 1.40, 1.95, 0.47.

Nymph. Final-instar nymph ( Fig. 9 ) is recognized by its generally yellow (partly tinged with green), ovoid, slightly elongate body; sparse, simple, short vestiture on dorsum; pale tibial spines; and reddish apical half of metafemur.

Differential diagnosis of adults. Recognized readily by elongate ovoid, medium sized body ( Figs 6–8 , 46 ); yellowish brown general colouration; darkened posterior part of pronotum, inner part of corium, and entire scutellum and clavus; and pale orange-brown apical half of metafemur.

Biology. Both adults and final-instar immatures of this mirid were collected from inflorescences of several unidentified broadleaf trees in Nepal and Thailand. A male adult was found on flowers of Styrax formosana Matsum. (Styracaceae) in Taiwan. In Rasuwa District, Nepal, a final-instar nymph was captured from inflorescence of Cotoneaster affinis Lindl. (Rosaceae) , which is considered as one of the breeding hosts, successfully developed into adult after a week reared with flesh of mango and banana as alternative diets ( Figs 9–11 ).

Distribution. Taiwan (Nantou, Kagi, Taoyuan) ( POPPIUS 1915 and additional records), Indonesia (Sumatra) (new record), Malaysia (Perak) (new record), Laos (Bolikhamsai) (new record), Nepal (Kathmandu Valley, Kasuki, Rasuwa) (new records), Thailand (Chiang Mai, Nakhon Ratchasima) (new records).

Comments. Judging from the overall features (elongate body form, keeled base of clavus, presence of a weak pygophoral spine, developed right paramere, general shape of endosoma, thick-rimmed, ovoid female sclerotized rings and wide, rectangular interramal lobes), the placement of this species in Prolygus is certain. However, its most closely related congener is yet to be confirmed. Now P. nigriclavus is known widely from Taiwan and the Oriental Region.

Figures

Figs 1–11. Habitus images of genuine Prolygus species, live individuals. 1–2 – P. disciger (Poppius, 1915) (1 –♁, Pingtung, Taiwan; 2 –♁, Chaiyaphum, Thailand), 3–5 – P. papuanus (Poppius, 1915) (3 – ♀, attracted to FL light in Brastagi, N. Sumatra; 4–5 – ♁, Kathmandu, Nepal), 6–11 – P. nigriclavus (Poppius, 1915) (6 – ♁, Kathmandu; 7 – ♀, Nakhon Ratchasima, Thailand; 8 – ♁, darkened individual, Nantou, Taiwan; 9–11 – reared ♁ emerging, Rasuwa, Nepal).

Figs 12–23. Scanning electron micrographs for genuine Prolygus species. 12–15 – P. disciger (Poppius, 1915), ♁: 12 – dorsal surface, 13 – cuneus and metatarsi, 14 – apical part of pygophore, left lateral view, 15 – scent efferent system; 16–17 – P. nigriclavus (Poppius, 1915), ♀: 16 – head and thorax, left lateral view, 17 – pretarsus (hind leg); 18–23 – P. papuanus (Poppius, 1915): 18 – ♀, dorsal surface, 19 – ♁, head and thorax, left lateral view; 20 – ♀, pretarsus (hind leg); 21 – ♀, dorsal vestiture (c: corium, p: pronotum, s: scutellum), 22 – ♁, apex of pygophore, left lateral view, 23 – ♁, metatarsus.

Figs 33–42. Male (33–40) and female (41–42) genitalia of Prolygus spp. 33–36 – P. nigriclavus (Poppius, 1915): 33 – apex of pygophore, caudal view; 34 – left paramere; 35 – right paramere; 36 – endosoma; 37–42 – P. papuanus (Poppius, 1914): 37 – apex of pygophore, dorsal view; 38 – right paramere; 39 – left paramere; 40 – endosoma; 41 – bursa copulatrix; 42 – posterior wall. Scale bars 0.2 mm.

Figs 43–53. Habitus images of genuine Prolygus spp, dry-preserved specimens in dorsal and ventral (46, 53) view. 43–44 – P. alboscutellatus Carvalho, 1987:43 –♀ (N. Sumatra); 44 –♁ (Negros, Philippines).45–46 – P. disciger (Poppius, 1915):45 –♀ (Iriomote Island, Japan), 46 –♁ (Pingtung, Taiwan); 47 – P. loriae (Poppius, 1914), holotype, ♁ (ZMUF); 48 – P. nigriclavus (Poppius, 1915) (N. Sumatra); 49 – P. palauensis (Carvalho, 1956), holotype, ♁ (USNM); 50–53 – P. papuanus (Poppius, 1914): 50 – ♁ (Perak, Malaya), 51 – ♁ (N. Sumatra), 52–53 – ♀ (N. Sumatra).

Figs 66–72. Asian species of Prolygus and related genera, type specimens. 66 – Lygus bakeri Poppius, 1915 [now in Anthophilolygus], paralectotypes; 67 – Lygus tainanensis Poppius, 1915 [synonym of A. bakeri]; 68 – Lygus nigriclavus Poppius, 1915 [now in Prolygus]; 69 – Lygus kirkaldyi Poppius, 1915 [synonym of Poppiolygus bengalicus]; 70 – Lygus bengalicus Reuter, 1885 [now in Poppiolygus], lectotype (herein designated) and paralectotype; 71 – Lygus niger Poppius, 1915 [now in Apolygopsis]; 72 – Lygus eous Poppius, 1915 [now in Apolygopsis]. Scale bars ca. 1 mm (based on original description of each taxon, except for Fig. 70 recently re-measured by courtesy of Prof. Enghoff of ZMUC).