Ephemera strigata Eaton 1892

Ephemera strigata Eaton, 1892 (Figs. 1J, 1K, 1L, 4D, 4H, 5D) Ephemera strigata Eaton 1892: 302; Tshernova, 1973: 332; Gose, 1981: 16. Specimens examined. South Korea: Gyeonggi-do: 4 male imagoes & 4 female imagoes, Gapyeong, 2003-V-18, 2013-VI-9. Gangwon-do: 36 larvae, 2 male subimagoes, 15 male imagoes & 26 female imagoes, Jeongseon, 2018-V-6-7, 2018-VI-2, Park SH, Kim JS, Mayorga A. Chungcheongbuk-do: 12 larvae, Danyang, 2007-VIII-25, Bae YJ. Diagnosis. Abdominal tergum I pale with a pair of dark thick lateral bars. Abdominal terga V- IX with a pair of dark thick lateral bars reaching the median area basally (Fig. 1J, 1K). Adult: Forewings transparent with dark brown marks on crossveins; costal area dark brown; CuA- MP2 not fused (Fig. 1L). Male genital lobes wide Y-shaped with a slight inner concavity; forks apex curved inertly; penis without distinct titillators (Fig. 5D). Mature larva. Generally similar to adults in abdominal markings. Posterior margin of tergum X quadrilateralshaped (Fig. 4H). Distribution. China, Japan [type locality], Korea, Mongolia, Russia. Remarks. This species has been frequently treated as an ecological model species of life history studies, intermediate host of nematodes, and population analysis using machine-learning techniques (Gose, 1970; Kuroda et al., 1984; Takemon, 1990; Hirasawa and Urabe, 2003; Li et al., 2020). In some immature larval specimens (7-12 mm in body length), abdominal terga VIII- IX are completely dark with a pair of pale median stripes, but this pigmentation changes to typical larval markings in the mature larvae.