Omoplax hisasuei Souma, 2025, sp. nov.

Omoplax hisasuei sp. nov. Figs 1 C, 2 C, 3 C, 4 C, 5 C, 6 C, 7 C, 8 C, 9 C, 10 C, 11 C, 12 C, 13 C, 14 C, 15 I Type material. Holotype, Japan • ♂; Ogasawara Isls., Hahajima Is., Mt. Kuwanoki; Neolitsea sericea var. aurata; 29 Sep. 2024; J. Souma leg.; SIHU. Paratypes, Japan • 6 ♂♂ 5 ♀♀; same data as for holotype; SIHU • 1 ♂ 1 ♀; same locality and date data as for holotype; Y. Hisasue leg.; SIHU • 1 ♂; same locality, host plant, and collector data as for holotype; 8 Mar. 2025; SIHU • 2 ♂♂; same locality, host plant, and collector data as for holotype; 9 Mar. 2025; SIHU • 13 ♂♂ 14 ♀♀; same locality data as for holotype; 22 May 2025; S. Shimamoto leg.; SIHU. Additional material examined. Non-types, Japan • 1 fifth instar nymph; same locality and date data as for holotype; Y. Hisasue leg.; SIHU. The single nymph recorded above is in poor condition and is thus not described in the present study. Diagnosis. Omoplax hisasuei 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 C); pronotal disc pale brown (Figs 3 C, 4 C, 5 C, 6 C); hood less than 0.5 times as wide as maximum width of head across compound eyes, not reaching apex of clypeus (Fig. 14 C); paranotum with areolae throughout its length; anterior margin of hemelytron strongly curved downward in apical half (Figs 7 C, 8 C, 9 C, 10 C); subcostal and discoidal areas of hemelytron united; costal area wider than fused subcostal and discoidal areas; Sc (subcosta) vein of hemelytron indistinct 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 C, 13 C). Description. Male. Head, antenna, calli, and legs in various shades of brown; pronotal disc, hood, median carina of pronotum, paranotum, posterior process, and hemelytron pale brown; markings on dorsum and ventral surface of body dark brown to black; compound eye dark red; areolae of pronotum and hemelytron transparent; pubescence on body yellowish (Figs 1 C, 3 C, 5 C, 7 C, 9 C, 11 C, 12 C). Body ovate; pubescence on body distinctly shorter than radius of compound eye (Figs 1 C, 12 C). Head (Figs 3 C, 5 C) 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 C) reaching middle part of mesosternum. Pronotum (Figs 1 C, 3 C, 5 C) glabrous. Pronotal disc coarsely punctate. Hood shorter than median carina of pronotum, higher than median carina, with 3–4 rows of areolae at highest part, less 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 1–2 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 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 C, 9 C) glabrous, extending beyond apex of abdomen; anterior margin strongly curved downward in apical half; apices separated from each other at rest; subcostal and discoidal areas united; costal area wider than fused subcostal and discoidal areas, with 4–5 rows of areolae at widest part; fused subcostal and discoidal areas with 7 rows of areolae at widest part; sutural area with 4–5 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 indistinct in apical part of dorsal view. Thoracic pleura smooth in anterior part, coarsely punctate in posterior part. Ostiolar peritreme oblong. Sternal laminae (Fig. 11 C) 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 C) smooth, covered with pubescence; femora thickest at middle. Abdomen ellipsoidal. Terminalia (Fig. 12 C) pentagonal in ventral view, covered with pubescence. Measurements (n = 24). Body length with hemelytra 3.05–3.30 mm; maximum width of body across hemelytra 1.65–1.75 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.20 mm, and 0.70 mm, respectively; pronotal length 1.10–1.20 mm; pronotal width across paranota 0.80–0.85 mm; hemelytral length 2.40–2.55 mm; maximum width of hemelytron 0.95–1.00 mm. Female. General habitus very similar to that of male (Figs 2 C, 4 C, 6 C, 8 C, 10 C, 13 C) except for the following characters: body wider than in male; antennal segments III and IV shorter than in male; hemelytron usually wider than in male; and apical part of abdomen pentagonal in ventral view. Measurements (n = 20). Body length with hemelytra 3.15–3.35 mm; maximum width of body across hemelytra 1.85–1.95 mm; length of antennal segments I to IV 0.20 mm, 0.10 mm, 1.10 mm, and 0.60 mm, respectively; pronotal length 1.15–1.20 mm; pronotal width across paranota 0.80–0.85 mm; hemelytral length 2.45–2.55 mm; maximum width of hemelytron 1.00– 1.05 mm. Remarks. Among all the species of Omoplax, O. hisasuei sp. nov. strongly resembles O. majorcarinae and O. mukojimensis in terms of its general habitus. However, based on a comparison of the type material of the new species together with the holotype or non-type material and the original descriptions (Guilbert 2001; Souma 2022 a) of O. majorcarinae and O. mukojimensis, three main characteristics were recognized to easily differentiate O. hisasuei sp. nov. from O. majorcarinae and O. mukojimensis (Figs 3 C, G, 4 C, G, H, 5 C, G, 6 C, G, H, 7 C, G, 8 C, G, H, 9 C, G, 10 C, G, H, 14 C, G, H): hood less than 0.5 times as wide as maximum width of head across compound eyes (more than 0.5 times as wide as maximum width of head across compound eyes in O. majorcarinae and O. mukojimensis); paranotum with areolae throughout its length (without areolae in middle part, with areolae in remaining parts in O. majorcarinae); and costal area wider than fused subcostal and discoidal areas (narrower than fused subcostal and discoidal areas in O. majorcarinae and O. mukojimensis). Morphological differences between O. hisasuei sp. nov. and the four other Omoplax species are presented in the identification key below. Distribution. Japan: Ogasawara Islands: Hahajima Group (Hahajima Island) (Fig. 19). Omoplax hisasuei sp. nov. is endemic to Hahajima Island. Etymology. This new species is named in honor of Yu Hisasue, a Japanese hymenopterist who collected some of the paratypes and has contributed to clarifying the species diversity of insects from the Ogasawara Islands. Host plant. Only Neolitsea sericea var. aurata (Lauraceae) (Fig. 17 E), which is also known as “ Kinshokudamo ”, was confirmed as a host plant for Omoplax hisasuei sp. nov. through field and captive observations of adults and nymphs, suggesting the possibility of monophagy for this lace bug species. Bionomics. Omoplax hisasuei sp. nov. inhabits an evergreen broad-leaved forest with a subtropical climate in the Ogasawara Islands and sucks sap on the abaxial side of the leaves of Neolitsea sericea var. aurata, causing irregular yellowing on the adaxial side (Fig. 17 E). Adults were collected in March, May, and September; a single nymph was collected in September.