Elasmostethus, : Kirkaldy, 1909

Jung, Sunghoon, 2017, Review of the genus Elasmostethus (Hemiptera: Heteroptera: Acanthosomatidae) from the Korean Peninsula, Zootaxa 4320 (2), pp. 351-365 : 363-364

Key to the Korean species of Elasmostethus

1 Mediotergites of abdominal segments V–VII entirely dark; posterior margin of pygophore with a pair of pigmented denticles ( Figs. 41–42 )......................................................................................... 2

- Mediotergites of abdominal segments V–VII at least partly pale; posterior margin of pygophore without paired pigmented denticles (a median projection might be present on ventral infolding)................................................ 3

2 Posterolateral angles of segment VII produced slightly beyond posterior margin of pygophore (Fig. 29); pigmented denticles on pygophore ( Fig. 41 : ld) situated far from submedian setal tufts, almost in middle of the lateral margin; posterior margins of abdominal segment VIII of female enclosing an obtuse angle, weakly protruding posteriad in the middle (Fig. 30)........................................................................................... E. brevis Lindberg, 1934

- Posterolateral angles of segment VII produced far beyond posterior margin of pygophore (Fig. 31); pigmented denticles on pygophore ( Fig. 42 : ld) situated immediately laterad of submedian setal tufts; posterior margin of abdominal segment VIII of the female slightly emarginate in the middle (Fig. 32)............................... E. interstinctus ( Linnaeus, 1758)

3 Mediotergites of abdominal segments V–VII entirely pale; pygophore with setal tuft at middle of ventral margin ( Figs. 43, 44 ); posterior margin of abdominal segment VIII of female convex at two sides, emarginate medially (Figs. 34, 36)........... 4

- Mediotergites of abdominal segments V–VII partly pale; pygophore without setal tufts ( Figs. 45, 46 ); female genital segment with posterior margin forming approximately a single arc, not emarginate medially (Figs. 38, 40)...................... 5

4 Ventral margin of pygophore with a single median setal tuft, its infolding with a long, dorsocaudally directed, sclerotized and pigmented projection ( Figs. 44, 47 ); paramere with bisinuate lateral margin ( Fig. 51 ); posterior margin of abdominal segment VIII of female deeply excised medially........................................... E. yunnanus Hsiao & Liu, 1977

- Ventral margin of pygophore with two (an upper and a lower) submedian pairs of setal tufts, without sclerotized median projection ( Fig. 43 ); paramere with simple, nearly straight lateral margin ( Fig. 50 ); posterior margin abdominal segment VIII of female slightly emarginate medially................................................. E. humeralis Jakovlev, 1883

5 Posterolateral angles of abdominal segment VII more strongly produced, sharp in both sexes (Figs. 37, 38); pronotum with more or less rectangular humeri; pygophore with rounded posterior margin provided with dense setae in ventral view (Fig. 37); paramere with obtuse outer apical angle ( Fig. 52 )......................................... E. nubilus (Dallas, 1852)

- Posterolateral angles of abdominal segment VII less strongly produced, obtuse in both sexes (Figs. 39, 40); pronotum with obtuse humeri; male genital segment with nearly straight posterior margin provided with sparse setae (Fig. 39); paramere with rounded outer apical angle ( Fig. 53 )................................................ E. rotundus Yamamoto, 2003

Figures

FIGURES 41 – 47. Pygophores of Elasmostethus spp. 41 – 46. posterior view; 47. lateral view; 41. E. brevis; 42. E. interstinctus; 43. E. humeralis; 44, 47. E. yunnanus; 45. E. nubilus; 46. E. rotundus. Lettering: ld = lateral denticle; mp = median process; lt = lower setal tuft; ut = upper setal tuft. Scale bars: 0.5 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.