Omoplax mukojimensis, Souma, 2022

Souma, Jun, 2022, Two new species of the genus Omoplax (Hemiptera: Heteroptera: Tingidae) from Mukojima Island, with new records of lace bugs endemic to the Ogasawara Islands, Japan, Acta Entomologica Musei Nationalis Pragae 62 (1), pp. 117-127 : 122-125

Omoplax mukojimensis sp. nov.

( Figs 1C , 2C, F , 3C, F , 4B, E , 5B )

Type material. Hඈඅඈඍඒඉൾ: ♀ (macropterous; Fig.1C ) ( KPMNH), “ 18.VI.2006 ” [= JAPAN: JAPAN: OGൺඌൺඐൺඋൺ Iඌඅൺඇൽඌ: Mukojima Group: Mukojima Island:Southern part, 18.vi.2006, leg. H. Karube].

Diagnosis. Omoplax mukojimensis sp. nov. is distinguished from the other species of Omoplax by the combination of the following characteristics: pronotal disc and body ventral side brown ( Figs 1C , 4B, E ); rostrum reaching middle part of mesosternum; hood with 3 rows of areolae on highest part ( Fig. 2F ); paranotum rounded throughout its length ( Figs 2C , 5B ); subcostal and discoidal areas of hemelytron indistinguishable ( Figs 3C, F ); and R+M (radiomedial) vein indistinct, not carinate.

Description. Macropterous female. Head, calli, pronotal disc, markings on hemelytra and ventral surface in various shades brown; compound eye dark red; hood, paranotum and hemelytron pale brown; areolae of pronotum and hemelytron transparent; pubescence on body yellowish ( Figs 1C , 2C, F , 3C, F , 4B, E ).

Body 1.8 times as long as maximum width across hemelytra ( Fig. 1C ). Head ( Figs 2C , 4F ) glabrous; pair of frontal spines separated from each other at apices, not reaching apex of clypeus; median spine as long as frontal spines, not reaching bases of frontal spines; pair of occipital spines longer than median spine, reaching middle part of compound eyes; antenniferous tubercles obtuse, slightly curved inward; clypeus smooth. Compound eye round in dorsal view. Antenna covered with pubescence; segment I cylindrical; segment II cylindrical, shortest among antennal segments; segment III longest among antennal segments; segment IV cylindrical, longer than segment I. Bucculae contiguous at anterior ends, with 3 rows of areolae throughout their length. Rostrum reaching middle part of mesosternum.

Pronotum ( Figs 2C, F , 5B ) 1.4 times as long as maximum width across paranota, glabrous. Pronotal disc coarsely punctate. Hood shorter than median carina of pronotum, narrower than vertex at widest part, higher than median carina of pronotum, with posterior margin extending to anterior part of pronotal disc, with 3 rows of areolae on highest part, with dorsal margin distinctly arched. Collar not covering compound eye. Median carina straight, extending to apex of posterior process, with 2 rows of areolae on highest part, with dorsal margin slightly arched. Calli smooth. Paranotum rounded throughout its length, subvertical, with 2 rows of areolae on widest part, with outer margin gently curved outward throughout its length. Posterior process triangular, obtuse at apex.

Hemelytron ( Figs 3C, F ) 2.6 times as long as its maximum width, extending beyond apex of abdomen, glabrous; maximum width across hemelytra 2.0 times as much as maximum width across paranota; apices close to each other in rest; subcostal and discoidal areas indistinguishable; costal area with 4 rows of areolae on widest part; subcostal-discoidal area with 7 rows of areolae on widest part; sutural area with 5 rows of areolae on widest part; hypocostal lamina with single row of areolae throughout its length; R+M (radiomedial) vein indistinct, not carinate.

Thoracic pleura ( Fig. 2F ) smooth in anterior part, coarsely punctate in posterior part. Ostiolar peritreme oblong. Sternal laminae ( Fig. 4B ) 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 to each other at posterior ends. Legs ( Fig. 1C ) smooth, covered with pubescence; femora thickest in middle. Abdomen ellipsoidal. Terminalia ( Fig. 4E ) pentagonal in ventral view, covered with pubescence.

Measurements (n = 1). Body length with hemelytra 3.3 mm; maximum width across hemelytra 1.8 mm; length of antennal segments I to IV 0.2 mm, 0.1 mm, 1.0 mm, and 0.6 mm, respectively; pronotal length 1.3 mm; pronotal width across paranota 0.9 mm; hemelytral length 2.6 mm; maximum width of hemelytron 1.0 mm.

Brachypterous morph. Unknown.

Male. Unknown.

Differential diagnosis. In the key to all described tingid species endemic to the Ogasawara Islands (Sඈඎආൺ & Kൺ- ආංඍൺඇං 2021), the new species described above differs from the other species in the combination of the following characteristics: head with very short spines ( Figs 2C, F , 5B ); paranotum rounded throughout its length; outer margin of paranotum without robust denticles throughout its length; anterior margin of hemelytron without robust denticles throughout its length ( Fig. 3C ); and R+M (radiomedial) vein of hemelytron without denticles throughout its length ( Fig. 3F ). In general appearance, Omoplax mukojimensis sp. nov. strongly resembles O. karubei sp. nov. described above. However, the former is easily distinguished from the latter by the following features: rostrum reaching middle part of mesosternum; hood with 3 rows of areolae on highest part; subcostal and discoidal areas of hemelytron indistinguishable; and R+M vein indistinct, not carinate.

Etymology. The specific epithet refers to its occurrence on Mukojima Island, the Ogasawara Islands, Japan; an adjective.

Biology. The holotype was collected in April. Nymph is unknown. It inhabits the laurilignosa ecosystem of the Ogasawara Islands in subtropical climate belonging to the Oceanian Region. Host plant is unknown.

Distribution. Japan: Ogasawara Islands: Mukojima Group: Mukojima Island.

Figures

Figs 1A–C. Two species ofOmoplax from Mukojima Island, the Ogasawara Islands, Japan, dorsal view:A, B – O. karubei sp. nov.:A – male, B – female. C – O. mukojimensis sp. nov.: female. Scale bar = 1.0 mm.

Figs 2A–F. Head and pronotum, dorsal and dorsolateral views: A, B, D, E – Omoplax karubei sp. nov.: A, D – male, B, E – female. C, F – O. mukojimensis sp. nov.: female. Scale bars = 0.2 mm.

Figs 3A–F. Hemelytra, dorsal and dorsolateral views: A, B, D, E – Omoplax karubei sp. nov.: A, D – male, B, E – female. C, F – O. mukojimensis sp. nov.: female. Scale bars = 0.2 mm.

Figs 4A–E. A–B – rostra and sternal laminae, ventral view:A – Omoplax karubei sp. nov.; B – O. mukojimensis sp. nov. C–E – apical part of the abdomen, ventral view: C, D – O. karubei sp. nov.: C – male, D – female; E – O. mukojimensis sp. nov.: female. Scale bars = 0.2 mm.

Figs 5A–B. Line drawings of head and pronotum, dorsal view: A – Omoplax karubei sp. nov.; B – O. mukojimensis sp. nov. Abbreviations: ca – calli; co – collar; ho – hood; mc – median carina; pa – paranotum; pd – pronotal disc; pp – posterior process. Scale bars = 0.2 mm.