Omoplax inugusu Souma, 2025, sp. nov.

Omoplax inugusu sp. nov. Figs 1 D, 2 D, 3 D, 4 D, 5 D, 6 D, 7 D, 8 D, 9 D, 10 D, 11 D, 12 D, 13 D, 14 D, 16 A, B Omoplax majorcarinae Guilbert, 2001: Souma and Kamitani (2021: 9) (distribution: part); Souma (2022 a: 126) (distribution: part); Shimamoto and Ishikawa (2023: 94) (catalog: part); Souma (2023: 9) (monograph). Misidentifications. Type material. Holotype, Japan • ♂; Ogasawara Isls., Hahajima Is., Tamagawa Dam; Machilus boninensis; 1 Oct. 2024; J. Souma leg.; SIHU. Paratypes, Japan • 2 ♂♂ 4 ♀♀; Ogasawara Isls., Hahajima Is., Kitamura; 4 Jun. 1976; T. Nakane leg.; 1 ♂ 3 ♀♀ referring to Souma (2022 a); NSMT • 1 ♂ 5 ♀♀; Ogasawara Isls., Hahajima Is., Mt. Chibusa; 21 Jun. 1994; Y. Kaneko leg.; referring to Souma and Kamitani (2021); TUA • 2 ♀♀; same locality data as for preceding; 7 Jul. 1997; K. Matsumoto leg.; referring to Souma (2022 a); NSMT • 1 ♂ 1 ♀; same locality and collector data as for preceding; 18 Jun. 2001; referring to Souma and Kamitani (2021); TUA • 1 ♂; same locality data as for preceding; 12 Jun. 2024; Y. Hisasue leg.; SIHU • 3 ♀♀; same locality data as for preceding; Machilus boninensis; 2 Oct. 2024; J. Souma leg.; SIHU • 1 ♀; Ogasawara Isls., Hahajima Is., “ 石門 ” [= Sekimon]; 27 Jun. 2009; Japan Forest Technology Association leg.; referring to Souma (2022 a); KPMNH • 2 ♂♂ 2 ♀♀; Ogasawara Isls., Hahajima Is., Mt. Sekimon; alt. 356 m; 22 Jun. 2022; S. Tomura leg.; SIHU • 2 ♀♀; same data as for holotype; SIHU • 1 ♂ 3 ♀♀; same locality data as for holotype; 27 Jun. 1996; K. Morimoto leg.; referring to Souma and Kamitani (2021); ELKU • 2 ♂♂ 4 ♀♀; same locality data as for holotype; 14 Jul. 2024; Y. Uehara leg.; SIHU • 1 ♂; Ogasawara Isls., Hahajima Is., Mt. Kichibe; 16 Jun. 2024; N. Tsuji leg.; SIHU • 1 ♂ 1 ♀; Ogasawara Isls, Hahajima Is., Nishidai; 10 Jun. 2025; N. Tsuji leg.; SIHU. Diagnosis. Omoplax inugusu sp. nov. is recognized among the other Omoplax species based on a combination of the following characteristics: rostrum reaching middle part of mesosternum (Fig. 11 D); pronotal disc black (Figs 3 D, 4 D, 5 D, 6 D); hood more than 0.5 times as wide as maximum width of head across compound eyes, not reaching apex of clypeus (Fig. 14 D); paranotum with areolae throughout its length; anterior margin of hemelytron not curved downward in apical half (Figs 7 D, 8 D, 9 D, 10 D); subcostal and discoidal areas of hemelytron not united; costal area narrower than combined width of subcostal and discoidal areas; Sc (subcosta) vein of hemelytron visible in apical part of dorsal view; R + M (fused radius and media) vein of hemelytron indistinct, not carinate; and ventral surface of body dark brown to black (Figs 12 D, 13 D). Description. Male. Markings on dorsum, head, hood, median carina of pronotum, paranotum, calli, posterior process, hemelytron, and ventral surface of body dark brown to black; antenna and legs in various shades of brown; pronotal disc black; compound eye dark red; areolae of pronotum and hemelytron transparent; pubescence on body yellowish (Figs 1 D, 3 D, 5 D, 7 D, 9 D, 11 D, 12 D). Body ovate; pubescence on body shorter than radius of compound eye (Figs 1 D, 12 D). Head (Figs 3 D, 5 D) glabrous; pair of frontal spines separated from each other at apices, not reaching apex of clypeus, occasionally reduced; median spine not reaching bases of frontal spines, occasionally reduced; pair of occipital spines not reaching anterior margin of compound eyes, occasionally reduced; antenniferous tubercle obtuse, curved inward, longer than frontal spines; vertex and clypeus smooth. Compound eye round in dorsal view. Antenna densely covered with minute pubescence on segments I to III and long pubescence on segment IV; pubescence on segment IV longer than pubescence on other parts of body; segment I cylindrical, shorter than segment IV; segment II cylindrical, shortest among antennal segments; segment III linear, longest amongst antennal segments; segment IV fusiform. Bucculae closed at anterior ends, with 3 rows of areolae at highest part. Rostrum (Fig. 11 D) reaching middle part of mesosternum. Pronotum (Figs 1 D, 3 D, 5 D) glabrous. Pronotal disc coarsely punctate. Hood shorter than median carina of pronotum, higher than median carina, with 4–5 rows of areolae at highest part, more than 0.5 times as wide as maximum width of head across compound eyes, not reaching apex of clypeus, without robust denticles throughout its length; dorsal margin arched; posterior margin extending to anterior part of pronotal disc. Collar not covering compound eye. Median carina straight, extending to apex of posterior process, with 2 rows of areolae at highest part, without robust denticles throughout its length; dorsal margin arched. Calli smooth. Paranotum subvertical, widened posteriad, with a single row of areolae in anterior half and 2–3 rows in posterior half; outer margin gently curved outward throughout its length, without robust denticles throughout its length. Posterior process triangular; apex rounded. Hemelytron (Figs 7 D, 9 D) glabrous, extending beyond apex of abdomen; anterior margin not curved downward in apical half; apices close to each other at rest; subcostal and discoidal areas not united; costal area narrower than combined width of subcostal and discoidal areas, with 4–5 rows of areolae at widest part; subcostal area with 3 rows of areolae at widest part; discoidal area with 4 rows of areolae at widest part; sutural area with 5 rows of areolae at widest part; hypocostal lamina with a single row of areolae throughout its length; Sc (subcostal) and Hc (hypocosta) veins distinct throughout their respective length; R + M (fused radius and media) and Cu (cubitus) veins indistinct throughout their respective length, not carinate; Sc and R + M veins without robust denticles throughout their respective length; Sc vein distinct in apical part of dorsal view. Thoracic pleura smooth in anterior part, coarsely punctate in posterior part. Ostiolar peritreme oblong. Sternal laminae (Fig. 11 D) lower than bucculae; pro- and mesosternal laminae open at both anterior and posterior ends; metasternal laminae as high as mesosternal laminae, open at anterior ends, fused with each other at posterior ends. Legs (Fig. 1 D) smooth, covered with pubescence; femora thickest at middle. Abdomen ellipsoidal. Terminalia (Fig. 12 D) pentagonal in ventral view, covered with pubescence. Measurements (n = 14). Body length with hemelytra 2.75–3.10 mm; maximum width of body across hemelytra 1.30–1.55 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.20 mm, and 0.60 mm, respectively; pronotal length 1.20–1.25 mm; pronotal width across paranota 0.75–0.80 mm; hemelytral length 2.05–2.30 mm; maximum width of hemelytron 0.80–0.90 mm. Female. General habitus very similar to that of male (Figs 2 D, 4 D, 6 D, 8 D, 10 D, 13 D) except for the following characters: body usually longer and wider than in male; antennal segments III and IV shorter than in male; hemelytron usually longer and wider than in male; and apical part of abdomen pentagonal in ventral view. Measurements (n = 31). Body length with hemelytra 2.90–3.15 mm; maximum width of body across hemelytra 1.55–1.65 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.10 mm, and 0.50 mm, respectively; pronotal length 1.20–1.30 mm; pronotal width across paranota 0.80–0.85 mm; hemelytral length 2.25–2.45 mm; maximum width of hemelytron 0.85–0.95 mm. Remarks. In the previous studies (Souma and Kamitani 2021; Souma 2022 a), Omoplax inugusu sp. nov. was identified as O. majorcarinae, but the former differs from the original description and the illustrations of the latter (Guilbert 2001) based on the following characters: body length with hemelytra 2.75–3.15 mm (3.45 mm in type material) (Figs 1 D, 2 D); maximum width of body across hemelytra 1.30–1.65 mm (1.85 mm in type material); pronotal disc black (Figs 3 D, 4 D, 5 D, 6 D); paranotum with areolae throughout its length (Fig. 14 D); anterior margin of hemelytron not curved downward in apical half (Figs 7 D, 8 D, 9 D, 10 D); and Sc (subcosta) vein of hemelytron distinct in apical part of dorsal view. These features were considered intraspecific variations of O. majorcarinae in the previous studies (cf. Souma and Kamitani 2021; Souma 2022 a), but constitute interspecific variation in the present study based on the examination of dozens of specimens which show two morphological species, each respectively collected from different plant species. Among all the Omoplax species, O. inugusu sp. nov. strongly resembles O. kobugashi sp. nov. in terms of its general habitus. However, based on a comparison of the type materials of O. inugusu sp. nov. and O. kobugashi sp. nov., three main characteristics were recognized to easily differentiate O. inugusu sp. nov. from O. kobugashi sp. nov. (Figs 3 D, F, 4 D, F, 5 D, F, 6 D, F, 7 D, F, 8 D, F, 9 D, F, 10 D, F, 11 D, F, 14 D, F): rostrum reaching middle part of mesosternum (reaching posterior margin of mesosternum in O. kobugashi sp. nov.); paranotum with areolae throughout its length (without areolae in middle part, with areolae in remaining parts in O. kobugashi sp. nov.); and anterior margin of hemelytron not curved downward in apical half (weakly curved downward in apical half in O. kobugashi sp. nov.). Morphological differences between O. inugusu sp. nov. and the five other Omoplax species are presented in the identification key below. Distribution. Japan: Ogasawara Islands: Hahajima Group (Hahajima Island) (Fig. 19) (Souma and Kamitani 2021; Souma 2022 a). Omoplax inugusu sp. nov. is endemic to Hahajima Island. Etymology. The specific epithet is the Japanese plant name “ Munin- inugusu ” [= Machilus boninensis], referring to the host plant of the new species; a noun in apposition. Host plant. Only Machilus boninensis (Lauraceae) (Fig. 17 F), which is also known as “ Munin- inugusu ”, was confirmed as a host plant for Omoplax inugusu sp. nov. by the field and captive observati