Poppiolygus bengalicus (Reuter, 1885) comb. nov.

(Figs 70, 90–93, 153–155, 164–169)

Lygus bengalicus Reuter, 1885: 195–196 (original description).

Lygus bengalicus: POPPIUS (1914):342 (key); SCHUH (1995): 808 (catalog, as insertae sedis).

Lygus kirkaldyi Poppius, 1915: 30 (original description). New synonymy.

Lygus kirkaldyi: POPPIUS (1914): 339 (key).

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

Prolygus kirkaldyi: SCHWARTZ & KERZHNER (1997): 254 (new combination); KERZHNER & JOSIFOV (1999): 172 (catalog); YASUNAGA (2001): 260 (diagnosis, host); ZHENG et al. (2004): 561 (diagnosis, key); NOZAKI et al. (2015): 17 (faunal list).

Type material examined. Lygus bengalicus: LECTOTYPE (here designated): ♁, [no collecting data label and original description only citing as Bengalia = possibly Indian West Bengal State], ZMUC 00 102141 (ZMUC, Fig. 70 left) (AMNH _ PBI 00380489). PARALECTOTYPE: 1 ♀, [same data], ZMUC 00 102142 (ZMUC, Fig. 70 right) (AMNH _PBI 00380490).

Lygus kirkaldyi: HOLOTYPE: ♀, TAIWAN: Formosa, Taihorinsho [= currently Dalin, Kagi District], 7 Nov, H. Sauter (Fig. 69, without USIs, image examined; genitalia dissected by the second author, DEIC).

Additional material examined. JAPAN: KYUSHU: Kagoshima Pref., Yakushima Island, Koidomari, 20 Sep 1990, collector unknown, 1 ♀ (TYCN). RYUKYUS: Amami-Oshima Island: Tasugo Town, 28.4, 129.5, on Persicaria sp. (Polygonaceae), 2 Sep 1997, M. Takai, 2 ♁♁ 2 ♀♀ (TYCN); Okinawa Island, Motobu, Izumi, 26.65, 127.95, on Persicaria sp., 21 Oct 1963, S. Miyamoto, 1♁ [det.by S. Miyamoto as “ Poppiolygus kirkaldy ”] (TYCN) (AMNH _PBI 00380491). MYANMAR: AYEYAWADY: Myaungmya, DOA Agriculture Research Station (rice paddy), 16°35 ′ 45.30 ″ N, 94°54 ′ 54.50 ″ E, on Persicaria sp., 28 Sep 2015, T. Yasunaga, 1 ♁ 1 ♀ (TYCN), (1 ♀, AMNH _PBI 00380492). MANDALAY: Mandalay Burma, 12 Mar 1908, Distant-Coll. 1911-383 [det. by Distant as Lygus bengalicus (DISTANT, 1904b)], 1 ♁ (BMNH). NEPAL: KASKI: Pokhara, 28.19, 83.95, on Persicaria sp., 16 Oct 2005, T. Yasunaga & R. K. Duwal, 5 ♁♁ 10 ♀♀ (CNC, NMTU, TYCN) (1 ♁, AMNH _PBI 00380493). THAILAND: NAKHON RATCHASIMA: Wang Nam Khieo, Udom Sap, Sakaerat Environmental Research Station, 14°30 ′ 27 ″ N, 101°55 ′ 39 ″ E, 410 m alt., UV light trap, 26 Sep 2013, T. Yasunaga, 1 ♀ (TYCN) (AMNH _PBI 00380494).

Measurements (in mm). ♁/ ♀: Total length of body 3.43 / 3.68; head width including eyes 0.87 / 0.87; vertex width 0.30 / 0.39; lengths of antennal segments I–IV 0.42, 1.43, 0.60, 0.50 / 0.39, 1.20, 0.71, 0.60; labial length 1.25 / 1.35; mesal length of pronotum including collar 0.72 / 0.75; basal width of pronotum 1.23 / 1.35; maximum width across hemelytron 1.62 / 1.68; and lengths of metafemur, tibia and tarsus 1.20, 1.95, 0.53 / 1.35, 1.95, 0.48.

Differential diagnosis. Recognized easily by ovoid, medium-sized body; shiny pale green general colouration (fading to brownish in dried specimens); reddish head, antennal segment I and apex of each femur; significantly shiny fuscous pronotum (posterior margin sometimes narrowly pale), with pale, arrow-shaped anteromedian part; more or less darkened apical inner corner of corium; and shape of male and female genitalia as mentioned in generic description (Figs 164–169). Final-instar nymph (Fig. 93) recognized by its ovoid, pale yellow-green body, and head, antennae, lateral part of pronotum and legs more or less tinged with red.

Biology. Both adults and late instar immatures were found on knotweeds (water peppers, cf. Figs 92–93), Persicaria spp. (Polygonaceae: Persicarieae) as reported by YASUNAGA (2001), and preferably feeding on the red inflorescences and young seeds. The unique color pattern (pale green mixed with black and red) is assumed to be cryptic, harmonious with the host plant inflorescences.

Comments. MIYAMOTO (1975) tentatively placed this species in Dagbertus, but he surely intended to propose a new genus for the taxon (personal communication to Yasunaga in the 1990’s; then he provided a male specimen from Okinawa, with a label handwritten as “ Poppiolygus kirkaldy ”). We positively agree with his memorable proposition, and the new genus Poppiolygus is herein established for this unique species, P. bengalicus.

Lygus kirkaldyi described from Taiwan by POPPIUS (1915) is herein synonymized with L. bengalicus from East India. Distribution of each species appeared disjunct, but the subsequent investigations suggested that a single species is distributed widely in the Oriental and eastern Palearctic Region. Judging from the revealed distribution pattern and same host association (knotweeds), the two nominal species are undoubtedly considered to be conspecific.