高翔蜉属一新种(蜉蝣目:扁蜉蝣科)

A NEW SPECIES OF GENUS EPEORUS EATON (EPHEMEROPTERA: HEPTAGENIIDAE)

本文记述采自湖南省大庸市高翔蜉属一新种。该种以其阳茎叶外侧面具有一向前弯曲的钩状突起为显著特征,可区别于本属其他种类。

The present treatise treats of a new species of the genus Epeorus Eaton, subgenus Iron col-lected in Dayong City, Hunan Province, China. With a hooky projection at lateral margin of penis as its striking feature, the said species is distinguishable from the rest of its congeners.Epeorus (Iron) dayongensis sp. nor (figs. 1-6)Male imago (in alc.): Length of body and forewing: equally 14-15 mm. Compound eyes, large, greyish-black and contiguous dorsally. The margin of forehead extending moderately toward the ventral side. Median ocellus round; lateral ocelli, kidney-shaped and connected with compound eyes. (the frontal view of head as shown in Figure 1) Mesonotum yellowish; scutum with a pair of yellowish-brown median longitudinal stripes. Forewing (as shown in Figure 2): membrane transparent, the costal and subcostal areas, opalescent and translucent; basal costal area cross veins well developed; stigmatic cross veins slightly oblique; cross veins in the costal, subcostal and first radius areas, margined with dark pigmentation; longitudinal and cross veins, brown in color. Hindwing (as shown in Figures 3-4): membrane transparent; the frontal margin of costal area with obtuse projection; two intercalary veins in cubital region; length: 0.3-0.33 as long as forewings. Forelegs, slightly longer than body, foretibiae 1.1-1.2 times longer than femora, tersi 1.9-2.0 times longer than femora and 1.5-1.6 times longer than foretibiae: descending length of tarsal segments in sequential order: 1,2 = 3, 4,5. Hin-dlegs with tibia 0.7-0.8 times longer than femora; tarsi 0.5-0.6 times longer than tibia and 0.4-0.5 longer than femora; descending length of tarsal segments in sequential order: 5= 1,2,3,4. Claws of all legs dissimilar with one blunt and the other hooky. Abdomen yellowish-white; terga 3-9 with a pair of brownish transversal stripes and with longitudinal stripes starting from its median site toward the right. Besides, terga 3-9 with a pair of well-developed, forward-inclining stripes; sterna 1-9 with dark brown longitudinal stripes. Genitalia: median site of subgenital plate evenly convex; penial lobes (as shown in Figures 5-6), rod-shaped with well-developed, forward-incurvating hooky projection at the outer lateral margin; terminal filament, degenerate with cerci about 4 times longer than body.Male subimago (in alc.): Identical with male imago in morphological characteristics but darker than male imago and opaque in wings.Holotype ♂ imago, Dayong(29°18'N,110°26'E), Hunan Province, 19. Ⅵ, 1986; paratypes 2♂♂ imagoes, 1♂ subimago, locality, same as holotype, 19-20, Ⅵ, 1986. All type specimens were collected by She Shusheng and Zhang Jun and leposited in the Department of Biology, Nanjing Normal University.