Neolygus hasegawai, Yasunaga, 2024

Yasunaga, Tomohide, 2024, New species of the plant bug genus Neolygus Knight from Japan, Taiwan and Thailand (Hemiptera: Heteroptera: Miridae: Mirini), Zootaxa 5446 (4), pp. 451-487 : 463-464

Neolygus hasegawai n. sp.

Figs. 4I , 8A–F , 16A–L

Material examined. Holotype (♂). JAPAN: Honshu, Fukushima Pref., Oze National Park, Tashiro , 36.977, 139.480, Angelica pubescens , 18 Jul 1950, H. Hasegawa ( NIAES) ( AMNH _ PBI 00378768 ) . Paratypes: JAPAN: same data as for holotype, except for date 17–18 Jul 1950, 2♂ 3♀ ( NIAES) .

Diagnosis. At first sight similar to the uniformly pale green, moderate-sized congeners, this new species is distinct in having the following characters: apex of clypeus darkened; apical protuberances of parameres bulbous; vesica with straight, apically widened spiculum and truncated apex of ventral sclerite; and dorsal sac with unique inner looped strap-like sclerite, strongly protruded and fused with anterior part of posterior wall ( Fig. 8F ).

Description. Body elongate oval, moderate in size ( Figs. 4I ); general coloration stramineous brown (most probably greenish when alive, fading in dry-preserved old specimens collected in 1950). Head shining; vertex relatively wide, with distinct basal transverse carina that is slightly narrower than pronotal collar ( Fig. 16B ); apex of clypeus infuscate. Antenna pale brown; segments III and IV darker. Labium pale reddish brown, reaching or slightly exceeding apex of mesocoxa. Pronotum and pleura uniformly pale brown; scent efferent system relatively narrow ( Fig. 16C ). Hemelytra immaculate; membrane pale smoky brown, with pale yellow veins. All coxae and legs pale; tibial spines pale reddish brown; pretarsal structure as in Fig. 16F . Ventral side of abdomen uniformly pale.

Male genitalia ( Figs. 8A–D , 16A–L ): Parameres with bulbous apical protuberances on sensory lobes ( Fig. 8A– B ); hypophysis of right paramere sharpened apically; vesica with spiculum widened apically and ventral sclerite truncated at apex ( Figs. 6E , 16H–I ).

Female genitalia ( Figs. 8G–I , 16J–L ): Sclerotized rings thick-rimmed, elongate-ovoid ( Fig. 8G , 14J ); posterior wall as in Fig. 14K–L ; dorsal sac with looped strap-like sclerite that is covered with membranous lobe, strongly protruded and fused with dorsoanterior part of posterior wall ( Fig. 8F , 16K ).

Measurements: See Table 1 .

Etymology. Named in honor of the late Mr. Hitoshi Hasegawa (1918–2006), one of well-known heteropterists in Japan; he collected all available specimens of this new species and N. yonanus n. sp. as well.

Distribution. Japan (Fukushima Pref.: Oze National Park).

Biology. Label data shows the specimens designated as type-series were collected from Angelica pubescens Maxim. (Umbelliferae), but the exact breeding host is yet to be confirmed.

Figures

FIGURE 4. Ventral (E, F, H), lateral (C) and dorsal habitus images of Japanese Neolygus spp., dry-preserved specimens. A. N. autumnus n. sp., holotype male. B–C. Same, female. D–E. N. chikanoshima n. sp., male. F. holotype female. G–H. N. chichibumontis n. sp., holotype male. I. N. hasegawai n. sp., holotype male.

FIGURE 6. Male (A–E, G–L) and female (F, M) genitalia of Neolygus autumnus n. sp. (A−F) and N. honshuensis (Linnavuori) (G–M).A, C, G, I. Left paramere. B, D, H, J, Right paramere. E, K, L. Vesica. F, M. Female genital chamber. Scale bars 0.2 mm. Abbreviations – GP: secondary gonopore, MS: median sclerite, PH: phallotheca, SP: spiculum, VS: ventral sclerite.

FIGURE 8. Male (A–D) and female (E–H) genitalia of Neolygus hasegawai n. sp. (A−F) and N. flavoviridis (Yasunaga) (G–H). A. Apex of genital segment (pygophore) with parameres, dorsal view. B. Same, ventral view. C, F. Vesica, ventral view. D, Same, dorsal view (side of secondary gonopore opening). E, G. Female genital chamber. F, H. Posterior wall of bursae. Scale bars 0.2 mm.

FIGURE 14. Scanning electron micrographs for Neolygus autumnus n. sp. (A−F) from Oita Pref. (A–C) and Kyoto Pref. (D–F), N. honshuensis (Linnavuori) (G−I) and N. chichibumontis n. sp., holotype male (J−O). A, D, G, O, Vesica. B, E, H, Posterior wall. C, F, I, Interramal lobe and lateral lobe of posterior wall. J, Head and pronotum, left lateral view. K, Metathoracic scent efferent system (left). L, Metatarsus. M, Pretarsal structure of metaleg. N, Apical pygophore (genital segment) with parameres, dorsal view. Abbreviations—BS: basal sclerite, GP: secondary gonopore, IRL: interramal lobe, IRS: interramal sclerite, LLB: lateral lobe, MS: median sclerite, PH: phallotheca, SP: spiculum, VS: ventral sclerite.

FIGURE 16. Scanning electronmicrographs forNeolygus hasegawai n.sp.(A−L), N.flavoviridis (Yasunaga)(M), N.hoberlandti (Kulik) (N) and N. makiharai (Yasunaga) (O). A, Anterior body, left lateral view. B, Head and pronotum. C, Thoracic pleura, left lateral view. D, Vestiture pattern of clavus and corium. E, Metatarsus. F, Pretarsal structure of metaleg. G, Apical pygophore (genital segment) with parameres, dorsal view. H, Vesica. I, Apex of vesical ventral sclerite. J, Genital chamber. K–O, Posterior wall.