Rhoenanthus sapa Nguyen & Bae, 2004

Han, Na, Zhang, Min & Zhou, Chang-Fa, 2021, The genus Rhoenanthus Eaton, 1881 in China with the redescription of R hunanensis You & Gui, 1995 (Ephemeroptera: Potamanthidae), Zootaxa 4903 (4), pp. 563-577 : 573

Rhoenanthus sapa Nguyen & Bae, 2004

Figs 10 A–C, 11

Rhoenanthus (Potamanthindus) sapa Nguyen & Bae, 2004: 13 , Figs 2–4 . Types: nymph, female, from Vietnam.

Rhoenanthus (Potamanthindus) sapa: Nguyen & Bae 2006: 23 .

Diagnosis: Nymphs of R. sapa can be distinguished from congeners by: mandibular tusks uniform pale but with scattered spines and rows of setae on dorsal surface, lateral margin with hair-like setae too ( Fig. 10A ); maxillary and labial palpi relatively shorter ( Fig. 10 B–C); pronotum without acute anterolateral projections, ridge on pronotum without anterior projection either; forelegs shorter than others, foretibiae also shorter, only subequal to femora in length ( Fig. 10A ); setae on tibiae and tarsi relatively less abundant ( Fig. 10A ).

Distribution: Vietnam, China (Yunnan, first record for China, Fig. 11 ).

Materials examined: 5 L, Xili River , Tuanjie town, Yunlong County, collected by Hui XIE, Yanyan JIA, Ping CHEN, VII-2008 ; 22 L, Gu River , Jingdong County, 15- IV- 2001 ; 10 L, Fengshan , Jinggu County, collected by Changfa ZHOU, 7- IV- 2001 ; all from Yunnan Province, China .

Figures

FIGURE 2. Nymphal characters of Rhoenanthus hunanensis (digital photos).A. Habitus in dorsal view; B. Head and pronotum of another more mature nymph (dorsal view, showing mandibular tusks); C. Enlarged section of the antenna.

FIGURE 3. Mouthparts of Rhoenanthus hunanensis nymph (digital photos).A. Labrum (dorsal view); B. Hypopharynx (ventral view); C. Labium (dorsal view); D. Left mandible (dorsal view); E. Right mandible (dorsal view); F. Maxilla (dorsal view).

FIGURE 4. Structures of Rhoenanthus hunanensis nymph (digital photos). A. Foreleg (dorsal view); B. Midclaw (dorsal view); C. Gill VII (dorsal view); D. Midleg (dorsal view); E. Hindleg (dorsal view); F. Gill I (dorsal view); G. Midtibia (ventral view, showing setae on surface); H. Distal part of hindleg (ventral view, arrow indicating the tuft of setae); I. Pronotum (dorsal view, arrow indicating the acute point of dorsal ridge).

FIGURE 10. Selected structures of Rhoenanthus spp. (digital photos). A–C. R. sapa; D–F. R. youi; G–I. R. obscurus: A, D, G. Anterior part of body (showing the relatively length of mandibular tusks, forelegs and their setae); B, E, H. Maxilla (dorsal view); C, F, I. Labrum (ventral view).

FIGURE 11. Chinese Rhoenanthus species distribution map.