Acanthomoplax tomokunii Souma & Kamitani 2021

Acanthomoplax tomokunii Souma & Kamitani, 2021 Figs 1 A, 2 A, 3 A, 4 A, 5 A, 6 A, 7 A, 8 A, 9 A, 10 A, 11 A, 12 A, 13 A, 14 A, 15 A – E Acanthomoplax tomokunii Souma & Kamitani, 2021: 6. Holotype: ♀; type locality: Japan • Ogasawara Isls., Hahajima I., Mt. Chibusayama [= Ogasawara Islands, Hahajima Group, Hahajima Island, Mt. Chibusa]; ELKU. References. Souma (2022 a: 125) (distribution); Shimamoto and Ishikawa (2023: 93) (catalog); Souma (2023: 9) (monograph). Material examined. Non-types, Japan • 2 ♂♂ 1 ♀; Ogasawara Isls., Ototojima Is., Kurohama – Ichinotani; Machilus kobu; 5 Oct. 2024; J. Souma leg.; three third or fourth instar nymphs developed into adults by 15 Oct. 2024 by feeding on Machilus kobu in captivity; SIHU • 1 ♀; same collection data as for preceding; a single egg has developed into a second instar nymph until 17 Oct. 2024 by feeding on Machilus kobu in captivity, and a second instar nymph developed into an adult by 30 Oct. 2024 by feeding on Machilus thunbergii in captivity; SIHU. Diagnosis. Acanthomoplax tomokunii is recognized among other lace bug species based on diagnostic characters mentioned in previous studies (Souma and Kamitani 2021; Souma 2022 a) and can be distinguished from the seven other lace bug species occurring in the Ogasawara Islands based on a combination of the following characteristics: pair of frontal spines reaching beyond apex of clypeus (Figs 3 A, 4 A, 5 A, 6 A, 14 A); median spine reaching beyond bases of frontal spines; pair of occipital spines reaching beyond anterior margin of compound eye; hood medially with robust denticles throughout its length; median carina of pronotum with robust denticles throughout its length; paranotum narrowed posteriad; outer margin of paranotum with robust denticles throughout its length; Sc (subcosta) vein of hemelytron with robust denticles throughout its length; and R + M (fused radius and media) vein of hemelytron with robust denticles throughout its length (Figs 7 A, 8 A, 9 A, 10 A). Remarks. Segmental oligomery of the antenna was confirmed in Acanthomoplax tomokunii, and one examined specimen lacks the left antennal segment IV (Fig. 2 A), as reported in many lace bugs (Štusák and Stehlík 1978). Distribution. Japan: Ogasawara Islands: Chichijima Group (Anijima Island, Ototojima Island), Hahajima Group (Hahajima Island) (Fig. 18) (Souma and Kamitani 2021; Souma 2022 a). Acanthomoplax tomokunii, which is endemic to the Ogasawara Islands, was confirmed in Ototojima Island during the survey in 2024 but has not been collected in Anijima and Hahajima islands since 2014 and 1999, respectively, despite extensive field surveys by numerous investigators (cf. Souma and Kamitani 2021; Souma 2022 a). Host plant. Machilus kobu (Lauraceae) (Fig. 17 A), which is also known as “ Kobugashi ” and is endemic to the Ogasawara Islands (Government of Japan 2010), was confirmed as a host plant for Acanthomoplax tomokunii through field and captive observations of adults and nymphs. In captivity, A. tomokunii fed on M. thunbergii Siebold & Zucc., “ Tabunoki ” (Fig. 17 B), which is not distributed in the Ogasawara Islands (Tanaka and Matsui 2007–2025), and a single second instar nymph developed normally to an adult in at least 13 days, suggesting the possibility of rearing this species in captivity using closely related species of M. kobu, which are not found in the native distribution area of A. tomokunii. However, to the best of the author’s knowledge, A. tomokunii feeds only on M. kobu in the field and appears to be monophagous. Additionally, the single individual in the present study was reared on M. kobu to the second instar nymph. Therefore, it is unclear whether rearing from oviposition to emergence can be achieved successfully only by feeding on M. thunbergii. Bionomics. Acanthomoplax tomokunii inhabits an evergreen broad-leaved forest with a subtropical climate in the Ogasawara Islands (Souma and Kamitani 2021), and sucks sap on the abaxial side of the leaves of M. kobu, causing irregular yellowing on the adaxial side (Fig. 17 A). Adults were collected in March and April, and from June to August (Souma and Kamitani 2021; Souma 2022 a); nymphs were collected in October.