Elasmostethus nubilus ( Dallas, 1851 )

Jung, Sunghoon, 2017, Review of the genus Elasmostethus (Hemiptera: Heteroptera: Acanthosomatidae) from the Korean Peninsula, Zootaxa 4320 (2), pp. 351-365 : 356

Elasmostethus nubilus ( Dallas, 1851)

Figs. 17, 18, 21, 22 , 37, 38, 45, 52, 58

Acanthosoma nubilum Dallas, 1851: 305 (original description). Type locality: Hong Kong.

Dichobothrium nubilum: Lee (1971: 226, 504) (part) (redescription, record from South Korea, distribution), Kwon et al. (2001: 373) (bibliography, record from South Korea, distribution, host plants).

Elasmostethus nubilus: Yamamoto (2003: 53, 63) (in key, redescription, figures, records, distribution, host plants), Göllner- Scheiding (2006: 173) (catalogue, distribution), Aukema et al. (2013: 431) (catalogue, distribution).

Diagnosis. Recognized by the mediotergites of abdominal segments V–VII being partly pale; the humeral angles of the pronotum being more or less rectangularly protruding; the posterolateral angles abdominal segment VII being moderately produced (sometimes not reaching apical margin of pygophore in the male), but with sharp apical angles in both sexes (Figs. 37–38); the posterior margin of the pygophore being broadly rounded in ventral view, provided with uniformly distributed, dense setae on its ventral margin (Fig. 37); the paramere with an obtuse outer apical angle ( Fig. 52 ); and the posterior margin of abdominal segment VIII of the female forming approximately a single arc (Fig. 38).

Measurements. ♂ / ♀. Body length 8.87–8.98/9.05–10.20; head width across eyes 1.66–1.69/1.72–1.75; lengths of antennal segments: scape 0.65–0.68/0.57–0.60, basipedicellite 1.25–1.28/1.05–1.22, distipedicellite 1.04–1.14/0.88–0.98, basiflagellum 1.17–1.50/1.19–1.30, distiflagellum 1.04–1.23/1.04–1.10; humeral width of pronotum 4.53–4.62/4.99–5.18; basal width of scutellum 2.40–2.51/2.75–2.80; length of scutellum 2.55–2.93/ 2.95–3.06; lengths of profemur and protibia 1.63–2.03/1.76–1.89, 1.96–1.98/1.75–1.83; lengths of mesofemur and mesotibia 1.85–1.92/2.11–2.18, 1.76–1.90/1.91–2.05; lengths of metafemur and metatibia 2.10–2.33/2.10–2.63, 2.45–2.63/2.41–2.63.

Material examined. SOUTH KOREA: Gyeonggi-do: Sohol-eup, Pocheon-si , South Korea, on Aralia cordata Thunb. , 06.ix.2014, WG. Kim (1 ♂ CNU) ; Yul-dong, Bundang-gu, Seongnam-si, on A. cordata Thunb. , 21.ix.2014, WG. Kim (7 ♀♀ CNU); Jangan-myeon, Hwaseong-si, 6.vii.2009. Y. Kwon (1 ♂ NIBR). Gyeongsangbuk-do: Naeseo-ri, Nongam-myeon, Mungyeong-si, on A. cordata Thunb. , 17.x.2014, WG. Kim (1 ♂ CNU) ; Namgok-ri, Euncheok-myeon, Sangju-si, on A. cordata Thunb. , 17.x.2014, WG. Kim (4 ♂♂ 4 ♀♀ CNU). Gyeongsangnam-do: Jangmok-myeon, Geoje-si, 21.vii.2009, JS. Park (3 ♀♀ NIBR) ; Mt. Sanbang, Sanbang-ri, Dundeok-myeon , Geoje-si , 7.v.2010, HJ. Kim (1 ♂ NIBR) . Jeju-do: Mt. Sanbang, Sagye-ri, Andeok-myeon , Seogwipo-si , 21.viii.2011, SH. Jung (1 ♂ 4 ♀♀ NIBR) ; Nokgome, Jangjeon-ri, Aewol-eup, Jeju-si, 18.vi.2011, SH. Jung (1 ♂ 1 ♀ NIBR); Gwakji-ri, Aewol-eup, Jeju-si, 17.ix.2011, SH. Jung (1 ♂ NIBR); Ora-dong, Jeju-si, 26.viii.2007, JL. Kim (3 ♂♂ 11 ♀♀ NIBR); Hyeopjae-ri, Hallim-eup, Jeju-si, 5.ix.2011, SW. Cheong (4 ♂♂ 1 ♀ NIBR); Jongdal-ri, Gujwa-eup, Jeju-si, 2.ix.2011, SW. Cheong (5 ♀♀ NIBR); Noro-oreum, Yusuam-ri, Aewoleup, Jeju-si, 11.xii.2003, Y. Kwon (2 ♂♂ 2 ♀♀ NIBR). Jeollanam-do: Sina-ri, Jinwol-myeon, Gwangyang-si, 13.ix.2010, J.A. Jeon (1 ♂ NIBR) ; Gohyeon-ri, Hyeonsan-myeon, Haenam-gun, 12.ix.2012, J.A. Jeon (1 ♀ NIBR).

Distribution. Korea, China, Japan, Taiwan.

Bionomics. This species is widely distributed in South Korea and it was collected on various species of Araliaceae ( Kwon et al. 2001, present study); host plants belonging to the same family were reported from Japan ( Yamamoto 2003).

Remarks. Some of the earlier records of Elasmostethus nubilus and E. humeralis from South Korea are apparently based on misidentification and pertain to E. rotundus and E. yunnanus . For example, fig. 82 in plate 10 of Lee (1971), labeled as E. nubilus , apparently represents a female of E. yunnanus .

Figures

FIGURES 17 – 24. Habitus of Elasmostethus spp. 17 – 20. dorsal view; 21 – 24. ventral view; 17, 21. E. nubilus ♂; 18, 22. E. nubilus ♀; 19, 23. E. rotundus ♂; 20, 24. E. rotundus ♀. Scale bars: 2 mm.

FIGURES 48 – 53. Right parameres of Elasmostethus spp. 48. E. brevis; 49. E. interstinctus; 50. E. humeralis; 51. E. yunnanus; 52. E. nubilus; 53. E. rotundus. Scale bars: 0.2 mm.