Miyamotolygus, Yasunaga & Schwartz & Chérot, 2018

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 : 379-380

Miyamotolygus gen. nov.

Type species. Lygocoris rufilorum Lu & Zheng, 1998 , here designated.

Diagnosis. Distinguished from other superficially similar genera by the following combination of characters: generally pale green, ovoid body; two types (pale simple setae and sericeous setae) of dorsal vestiture; narrow but continuous basal carina of vertex; red stripe on lorum; uniformly linear antenna slightly shorter than body; darkened extreme apices of clavus, embolium and cuneus; broadly reddish brown metafemur; and unique shape of male and female genitalia.

Description. Male. Body ovoid, rather small to moderate in size (3.9–4.5). COLOURATION: Generally pale (somewhat olive) green, partly with brownish or reddish patterns ( Figs 63 , 88–89 , 148 ). Maxillary plate with red stripe. Apices of clavus and scutellum dark or reddish brown; apex of embolium usually faintly darkened. Metafemur with apical 0.66 deep reddish brown; each tibia without dark spots at bases of spines; tibial spines dark or reddish brown. Ventral surface of abdomen partly or widely darkened (♁ in particular). SURFACE AND VESTITURE: Dorsal surface shining, with uniformly distributed, simple, silky, reclining setae, partly mixed with sericeous, reclining setae on mesoscutum, scutellum and hemelytron ( Figs 63 , 88–89 , 148 ). Pronotum shiny, uniformly and shallowly punctate. STRUCTURE: Head vertical, short; vertex with continuous, narrow, basal transverse carina about as thick as antennal segment III. Antenna uniformly slender and linear, slightly shorter than body; segment II slightly longer than basal width of pronotum; segment IV slightly longer than I. Labium reaching or slightly exceeding apex of mesocoxa. Calli rather clearly demarcated from disc; collar slightly thicker than basal carina of vertex; scutellum weakly inflated mesally; hemelytron not strongly declivous at cuneal fracture. Metafemur relatively tumid; tarsomere III longer than I or II. GENITALIA ( Figs 159–161 ): Pygophore weakly pointed at apex, lacking spine at base of left paramere. Left paramere ( Fig. 160 ) with sensory lobe not developed basally; hypophysis with a small branch at apex; right paramere ( Fig. 159 ) short, straight, about half as long as left one, with small, flattened hypophysis. Endosoma ( Fig. 161 ) with long, flat primary lobal-sclerite (PL) and secondary lobal-sclerite (SL), densely furnished with noticeable hair-like spinules above heavy- rimmed secondary gonopore (GP); third lobe (TL) with sclerotized process apically and dentate sclerite at middle.

Female. As in male. GENITALIA ( Figs 162–163 ): Bursa copulatrix rather heavily sclerotized ( Fig. 162 ), with sclerotized structure; sclerotized rings thick-rimmed, large, teardrop-shaped; posterior wall with median process, lacking dorsal structure; lateral lobe narrow, toughened with sclerotized dorsal margin; interramal lobe small, thick, triangular, spinulate; interramal sclerite wide ( Fig. 163 ).

Etymology. Named in honor of the late Japanese heteropterist, Dr. Syoiti Miyamoto (1913–2010) ( ISHIKAWA & HAYASHI 2012), combined with the mirine generic name Lygus ; masculine.

Distribution. India (Darjeeling) ( YASUNAGA et al. 2012), SW Japan (Kyushu) (new record), Nepal ( YASUNAGA et al 2012), P. R. China (Fujian, Guanxi, Shaanxi, Sichuan, Yunnan, Zejiang) ( LU & ZHENG 1998a, YASUNAGA et al 2012, ZHENG et al. 2004), Taiwan ( ZHENG et al. 2004), and N. Thailand (new record).

Discussion. Miyamotolygus is reminiscent of Neolygus (as the type species was described under this taxon), but the following characters clearly distinguish this new genus from Neolygus: Darkened extreme apices of clavus, embolium and cuneus (shared by Anthophilolygus ); shorter labium slightly exceeding apex of mesocoxa; broadly reddish brown metafemur; apex of left paramere hypophysis with a lateral process (shared by Apolygopsis , Micromimetus and Prolygus ); endosoma with bundles of distinct hair-like spinules ( Fig. 161 ); elongate, flattened endosomal primary (PL) and secondary (SL) lobal-sclerites ( Fig. 161 ) that are not arising from cup-like endosomal base ( Fig. 175 , EDB); female bursa copulatrix with toughly sclerotized genital chamber ( Fig. 162 vs. Fig. 176 ); posterior wall rather similar in general shape to that of Apolygus , with small, triangular interramal lobe and heavily sclerotized anterior margin of lateral lobe ( Fig. 163 vs. Fig. 177 ). The similarities between the present new genus and Neolygus are considered only superficial.

As mentioned above, Miyamotolygus has some characters shared by Anthophilolygus , Apolygus , Apolygopsis , Micromimetus and/or Prolygus . Currently, it seems difficult to elucidate the relationship of Miyamotolygus to these genera. Judging from sharing the pale green body with darkened extreme apices of clavus, cuneus and embolium, dark reddish brown apical part of metafemur, and presence of hair-like spinules on the endosoma, Anthophilolygus is presumed to be the closest taxon among known mirine genera. However, the definitive systematic position will depend on the acquisition of DNA sequence data.

In addition to the type species, two additional species originally described from continental China under Neolygus are also transferred here to Miyamotolygus .

Figures

Figs 54–65. Habitus images of species of the Lygus complex. 54–55 – Anthophilolygus alaneylesi sp. nov. (Nakhon Nayok, Thailand): 54 – ♀, ventral view, 54 –♁; 56–57 – A. bakeri (Poppius, 1915): 56 –♁ (Nagasaki, Japan), 57 –♀ (Okinawa, Japan); 58 – Lygus dybasi Carvalho, 1956,♁ (KUEC) with incorrect paratype label and determination (as Lygus yapensis n. sp.); 59 – Micromimetus rubrotinctus (Carvalho, 1956), allotype♀; 60–61 – M. sunweni sp. nov.: 60 – holotype,♁, 61 – same, left lateral view; 62–63 – Miyamotolygus rufilorum (Lu & Zheng, 1998) (Kathmandu, Nepal): 62 –♁, ventral view, 63 – ♀; 64 – Dagbertus darwini (Butler, 1904), holotype (Galapagos, BMNH); 65 – D. olivaceus (Reuter, 1907), ♁ (Florida, USA). Scale bars 2 mm.

Figs 83–93. Habitus images of Asian species of the Lygus complex. 83–84 – Apolygopsis nigra sp. nov. (Poppius, 1915): 83 – ♁ (Nakhon Ratchasima, Thailand), 84 – ♀ (Kathmandu, Nepal). 85 – Apolygopsis nigritula (Linnavuori, 1961), ♀ (Nagasaki, Japan). 86 – Apolygopsis furvocarinata Yasunaga, Schwartz & Chérot, 2002, adults aggregated on Fraxinus griffitii (Iriomote Island, Japan). 87–89 – Miyamotolygus rufilorum (Lu & Zheng, 1998) (Kathmandu, Nepal): 87–88 – ♁, 89 – ♀. 90–93 – Poppiolygus bengalicus (Reuter, 1885): 90 –♀ (Nakhon Ratchasima, Thailand), 91 – ♀ (Ayeyawady, Myanmar), 92 – ♁ (Kaski, Nepal), 93 – final instar nymph (Kasuki).

Figs 147–158. Scanning electron micrographs for Miyamotolygus rufilorum (Lu & Zheng, 1998) (147–152) and Poppiolygus bengalicus (Reuter, 1885) (153–158). 147, 153 – head and thorax, dorsal view; 148, 154 – dorsal vestiture pattern (c: corium, p: pronotum, s: scutellum); 149 – head and thorax, left lateral view; 150, 157 – metatarsus; 151 – pretarsus (hind leg); 152, 158 – pygophore, left lateral view; 155 – scent efferent system; 156 – protarsus.

Figs 159–169. Male (159–161, 164–167) and female (162–163, 168–169) genitalia of Miyamotolygus rufilori (Lu & Zheng, 1998) (159–163) and Poppiolygus bengalicus (Reuter, 1885) (164–169). 159 – apex of pygophore with parameres, ventral view; 160, 165 – left paramere; 166 – right paramere; 161, 167 – aedeagus; 162, 168 – bursa copulatrix, dorsal view; 163, 169 – posterior wall, anterior view; 164 – apex of pygophore with parameres, dorsal view. Scale bars 0.2 mm.

Figs 170–177. Male (170–175) and female (176–177) genitalia of the taxa superficially similar to Prolygus. 170–172 – Apolygus pulchellus (Reuter, 1906) (Nagasaki, Japan): 170 – left paramere, 171 – right paramere, 172 – endosoma. 173–175 – Neolygus honshuensis (Linnavuori, 1963) (Hokkaido, Japan): 173 – left paramere, 174 – right paramere, 175 – endosoma. 176–177 – N. zhugei (Yasunaga, 1992) (Nagasaki): 176 – bursa copulatrix, dorsal view; 176 – posterior wall, anterior view. Additional abbreviations: BSC – basal sclerite; EDB – endosomal base; VSC – ventral sclerite.