Orthonotus nakagawai n. sp.

(Fig. 9 A−C, H; 10D−G; 16; 23D−I; 24D−H, N; 25A−F)

Material examined. Holotype (♂). JAPAN: Akita Pref., Senboku City, Tazawako-Tamagawa, Play-Park Toze, 405 m, 39.8980, 140.6920, 27 Jun 2021, Y. Nakagawa (AMNH) (AMNH _ PBI 00380702). Paratypes: JAPAN: Honshu, same data as for holotype, 3♂ (TYCN); same data except for date, 22 Jun 2021, 7♂ 5♀ (NCA, TYCN); Senboku City, Tazawako-Tamagawa, 410 m, 39.86, 140.70, 3 Jul 2021, UV lighting, 1♂ (TYCN). All specimens were collected by Y. Nakagawa.

Diagnosis. This new species can be readily distinguished from two other East Asian congeners by the characters mentioned in the above key. The final instar nymph is recognized by the ovoid body, reddish brown general coloration, sparse vestiture on dorsum, and white bases of antennal segments II and III (Fig. 9C).

Description. Body elongate-oval in both sexes, weakly declivous at cuneal fracture (Figs. 9A–B, H), not sexually dimorphic in coloration and external structures; basic coloration fuscous; dorsal surface weakly shining, with uniformly distributed, brown, simple setae and relatively sparser, silvery, reclining, lanceolate setae (Fig. 23E, 24N). Head fuscous; eye large. Antenna dark brown; segments I (except for apical reddish ring) and II (except for darkened extreme base and apical 1/3) yellowish brown; segment II more widely pale and not darkened basally in ♀ (Fig. 9B); base of segment III creamy yellow. Labium yellowish brown, slender, its apex reaching but not exceeding apex of metacoxa; entire segment I, extreme base of II and apical half of segment IV dark reddish brown. Pronotum, mesoscutum and scutellum shiny fuscous, with sparsely distributed, silvery setae; pleura dark reddish brown; metathoracic scent efferent system dark grayish brown, with relatively small peritreme (Fig. 23F). Hemelytron shiny dark brown, with almost uniformly distributed, silvery setae that are longer than those of two other E. Asian species (Fig. 24N); membrane smoky brown. Coxae and legs generally pale reddish brown (Fig. 9H); base of each femur narrowly darkened; all tibia entirely pale brown, without dark spots; tibial spines pale reddish brown; all tarsi yellowish brown; pretarsal structure as in Fig. 23I; pulvilli somewhat enlarged; parempodia hairlike. Abdomen shiny dark reddish brown. Male genitalia (Figs. 10 D−E; 24D−H): Ventral apical keel on pygophore developed (Figs. 10D, 24D); phallotheca long, almost straight (Fig. 24E); vesica sigmoid, apically with subapical knob-like process and hooked apex (Figs. 10E, 24G–H). Female genitalia (Figs. 10 F−G; 25A−F): Sclerotized rings thick-rimmed, small, with ovoid inner margin and sharp lateral edge (Figs. 10F, 25E); posterior wall relatively narrow (Fig. 25B–C).

Measurements: See Table 3.

Etymology. Named for Mr. Y. Nakagawa (Akita, Japan), who collected the only known specimens designated as type-series and who shared some biological data.

Distribution. Japan (North Honshu: Akita).

Biology. Both adults and final instar nymphs were collected in late June 2021 by sweep-netting the various broadleaf trees, herbs, and ferns (Nakagawa, pers. comm.). Currently, the breeding host is yet to be confirmed. Collection records suggest this new species has a univoltine life cycle.