Omoplax kobugashi Souma, 2025, sp. nov.
Omoplax kobugashi sp. nov. Figs 1 F, 2 F, 3 F, 4 F, 5 F, 6 F, 7 F, 8 F, 9 F, 10 F, 11 F, 12 F, 13 F, 14 F, 16 C – F Omoplax majorcarinae Guilbert, 2001: Souma and Kamitani (2021: 9) (distribution: part); Souma (2022 a: 126) (distribution: part); Shimamoto and Ishikawa (2023: 93) (catalog: part); Souma (2023: 9) (monograph). Misidentifications. Type material. Holotype, Japan • ♂; Ogasawara Isls., Chichijima Is., Mt. Mikazuki; Machilus kobu; 22 Sep. 2024; J. Souma leg.; SIHU. Paratypes, Japan • 1 ♂; Ogasawara Isls., Chichijima Is.; 4 May 1976; Y. Hori leg.; referring to Souma (2022 a); NSMT • 1 ♀; Ogasawara Isls., Chichijima Is., “ 大村 ” [= Omura]; 18 Jun. 1976; Y. Kurosawa leg.; referring to Souma (2022 a); NSMT • 1 ♂ 1 ♀; Ogasawara Isls., Chichijima Is., Tokoyo Falls – Tastumizaki; 29 Jun. 1994; Y. Kaneko leg.; referring to Souma and Kamitani (2021); TUA • 1 ♀; Ogasawara Isls., Chichijima Is., Mt. Chuosan; 30 Jun. 1994; Y. Kaneko leg.; referring to Souma and Kamitani (2021); TUA • 1 ♂ 4 ♀♀; same locality data as for preceding; 27 Jun. 2001; K. Matsumoto leg.; 1 ♂ 2 ♀♀ referring to Souma and Kamitani (2021); TUA • 1 ♀; same locality data as for preceding; 22 Jun. 2024; Y. Hisasue leg.; SIHU • 1 ♀; Ogasawara Isls., Chichijima Is., Mt. Tsutsuji; 28 Jul. 1996; T. Kishimoto leg.; referring to Souma (2022 a); NSMT • 1 ♂ 1 ♀; Ogasawara Isls., Chichijima Is., Mt. Yoake; 14 Jun. 1999; K. Morimoto leg.; referring to Souma and Kamitani (2021); ELKU • 1 ♀; Ogasawara Isls., Anijima Is., “ ヤギ 柵手前 ” [= Front of goat fence located at Central plateau]; 8 Jul. 2009; Japan Forest Technology Association leg.; referring to Souma (2022 a); KPMNH • 1 ♂; Ogasawara Isls., Anijima Is., Mt. Mikaeri, Anbu; Malaise trap; 4 Jul. 2014; D. Watabiki leg.; referring to Souma and Kamitani (2021); TUA • 1 ♀; same locality, trap, and collector data as for preceding; 28 Jul. 2014; referring to Souma and Kamitani (2021); TUA • 1 ♀; Ogasawara Isls., Anijima Is., Mt. Omaru; 25 Jun. 2023; Y. Hisasue leg.; SIHU • 1 ♂; Ogasawara Isls., Anijima Is., Mt. Maruyama; 2 Jul. 2024; Y. Hisasue leg.; SIHU • 1 ♂ 1 ♀; Ogasawara Isls., Anijima Is., Southwest foot of Mt. Token; 8 Jul. 2024; N. Tsuji leg.; SIHU • 1 ♂; Ogasawara Isls., Chichijima Is., Mt. Tsuitate; 19 Jul. 2024; Y. Hisasue leg.; SIHU • 1 ♀; same data as for holotype; SIHU • 3 ♂♂ 4 ♀♀; Ogasawara Isls., Anijima Is., Tamana Beach – Mt. Mikaeri; Machilus kobu; 24 Sep. 2024; J. Souma leg.; SIHU. Additional material examined. Non-types, Japan • 1 fifth instar nymph 1 fourth instar nymph; Ogasawara Isls., Anijima Is., Tamana Beach – Mt. Mikaeri; Machilus kobu; 24 Sep. 2024; J. Souma leg.; SIHU. The two nymphs recorded above are in poor condition and are thus not described in the present study. Diagnosis. Omoplax kobugashi sp. nov. is recognized among the other Omoplax species based on a combination of the following characteristics: rostrum reaching posterior margin of mesosternum (Fig. 11 F); pronotal disc black (Figs 3 F, 4 F, 5 F, 6 F); hood more than 0.5 times as wide as maximum width of head across compound eyes, not reaching apex of clypeus (Fig. 14 F); paranotum without areolae in middle part, with areolae in remaining parts; anterior margin of hemelytron weakly curved downward in apical half (Figs 7 F, 8 F, 9 F, 10 F); subcostal and discoidal areas of hemelytron not united; costal area narrower than combined width of subcostal and discoidal areas; Sc (subcosta) vein of hemelytron distinct 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 F, 13 F). 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 F, 3 F, 5 F, 7 F, 9 F, 11 F, 12 F). Body ovate; pubescence on body shorter than radius of compound eye (Figs 1 F, 12 F). Head (Figs 3 F, 5 F) 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 F) reaching posterior margin of mesosternum. Pronotum (Figs 1 F, 3 F, 5 F) 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 part and 1–2 rows in posterior part, without areolae in middle part; outer margin gently curved outward in posterior part and straight in remaining parts, without robust denticles throughout its length. Posterior process triangular; apex rounded. Hemelytron (Figs 7 F, 9 F) glabrous, extending beyond apex of abdomen; anterior margin weakly 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 F) 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 F) smooth, covered with pubescence; femora thickest at middle. Abdomen ellipsoidal. Terminalia (Fig. 12 F) pentagonal in ventral view, covered with pubescence. Measurements (n = 13). Body length with hemelytra 2.60–2.80 mm; maximum width of body across hemelytra 1.20–1.35 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.10 mm, and 0.60 mm, respectively; pronotal length 1.15–1.25 mm; pronotal width across paranota 0.70–0.75 mm; hemelytral length 1.95–2.15 mm; maximum width of hemelytron 0.75–0.80 mm. Female. General habitus very similar to that of male (Figs 2 F, 4 F, 6 F, 8 F, 10 F, 13 F) 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 = 21). Body length with hemelytra 2.70–3.05 mm; maximum width of body across hemelytra 1.40–1.50 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.00 mm, and 0.50 mm, respectively; pronotal length 1.15–1.30 mm; pronotal width across paranota 0.70–0.80 mm; hemelytral length 2.00– 2.25 mm; maximum width of hemelytron 0.80–0.85 mm. Remarks. In previous studies (Souma and Kamitani 2021; Souma 2022 a), Omoplax kobugashi sp. nov. was identified as O. majorcarinae, but the former differs from the original description and the illustrations of the latter (Guilbert 2001) in the following characters: body length with hemelytra 2.60–3.05 mm (3.45 mm in type material) (Fig. 1 F, 2 F); maximum width of body across hemelytra 1.20–1.50 mm (1.85 mm in type material); rostrum reaching posterior margin of mesosternum (Fig. 11 F); pronotal disc black (Figs 3 F, 4 F, 5 F, 6 F); anterior margin of hemelytron weakly curved downward in apical half (Figs 7 F, 8 F, 9 F, 10 F); and Sc (subcosta) vein of hemelytron distinct in apical part of dorsal view. These features were considered an intraspecific variation of O. majorcarinae in 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. In general appearance, Omoplax kobugashi sp. nov. is very similar to O. desecta, whose distribution range in Chichijima Group is consistent with that of O. kobugashi sp. nov. (Souma and Kamitani 2021; Souma 2022 a), but the former can be distinguished from the latter based on the rostrum reaching the posterior margin of the mesosternum (reaching the posterior margin of the metasternum in O. desecta) and the black pronotum (pale brown in O. desecta) (Figs 3 B, F, 4 B, F, 5 B, F, 6 B, 1
Institutions
- Hirosaki University (JP)
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2025-08-29
- DOI
- https://doi.org/10.5281/zenodo.16995399
- Primary Topic
- Geochemistry and Geologic Mapping
- Type
- article
- Field-Weighted Citation Impact
- 0.00