Afronurus species

Zhang, Wei, Lei, Zhi-Ming & Zhou, Chang-Fa, 2021, A contribution to the genus Afronurus Lestage, 1924 in China (Ephemeroptera: Heptageniidae, Ecdyonurinae), European Journal of Taxonomy 767 (1), pp. 94-116 : 113-114

Key to six common Chinese Afronurus species (nymph)

1. Anterior margin of head capsule without pale dot ............................................................................ 2

– Anterior margin of head capsule with pale dots ............................................................................... 3

2. Lingua and superlinguae subequal in length (as in Fig. 8B ); crown of galea-lacinia with 12–14 comb-shaped setae; caudal filaments pale but with brown dots on articulations ( Fig. 7O ); glossae slightly oblong (as in Fig. 2F ) ........................................................ A. yixingensis ( Wu & You, 1986)

– Lingua obvious shorter than superlinguae ( Fig. 10B ); crown of galea-lacinia with 16–18 combshaped setae; proximate part of caudal filaments pale but other parts yellowish brown ( Fig. 7F ); glossae lobe rounded ( Fig. 10E ) ............................................... A. hunanensis ( Zhang & Cai, 1991)

3. Head capsule with two rows of pale dots (8–9) on anterior margin ( Fig. 7G, J ); caudal filaments with brown stripes on articulations ( Fig. 7I, L, O ) ................................................................................... 4

– Head capsule with 2–5 pale dots on anterior margin ( Figs 1A , 7A ); caudal filaments pale to yellowishbrown, without any stripe ( Figs 1A , 7C ) .......................................................................................... 5

4. Abdominal terga with oblique stripes laterally ( Fig. 7H ); crown of galea-lacinia with 11–13 combshaped setae; posterolateral projections of segments III–VIII moderately developed ( Fig. 7H ); lingua shorter than superlinguae (as in Fig. 10B ) ................................. A. obliquistriatus ( You et al., 1981)

– Abdominal terga without oblique stripes; crown of galea-lacinia with 14–16 comb-shaped setae; posterolateral projections of segments III–VIII weakly developed (as in Fig. 7E ); lingua and superlinguae subequal in length (as in Fig. 2C ) ..................... A. rubromaculatus ( You et al., 1981)

5. Gill I sickle-like ( Fig. 3F ); glossae slightly oblong ( Fig. 2F ) .................. A. drepanophyllus sp. nov.

– Gill I banana-shaped ( Fig. 9F ); glossae lobe rounded ( Fig. 8E ) ........................................................ ...................................................................................................... A. furcatus ( Zhou & Zheng, 2003)

Key to six common Chinese Afronurus species (male imago)

1. Penes with plate-like titillators ......................................................................................................... 2

– Penes with spine-like titillators ......................................................................................................... 3

2. Penes connected by foliated structure at ⅔ length from base; titillators about ⅔ of penes in length ( Fig. 13A–B ) ................................................................................ A. furcatus ( Zhou & Zheng, 2003)

– Penes lobes widely divergent; titillators about half of penes in length ( Fig. 13C–D ) ........................ ................................................................................................... A. hunanensis ( Zhang & Cai, 1991)

3. Remarkable projection between divergent penial lobes ................................................................... 4

– Penial lobes divergent but without projection between them ........................................................... 5

4. Spine-like projection between two penial lobes ( Fig. 13I–J ); abdominal terga with two yellowishbrown longitudinal stripes submedially ( Fig. 12E ) ....................... A. yixingensis ( Wu & You, 1986)

– Cone-shaped projection between two penial lobes ( Fig. 13G–H ); abdominal terga I–IX with distinguishable reddish stripes laterally ( Fig. 12D ) ................ A. rubromaculatus ( You et al., 1981)

5. Abdominal terga transparent, with brown oblique stripes laterally ( Fig. 12C ); penial lobes slightly divergent and with a narrow V-shaped cleft between them ( Fig. 13E–F ) .......................................... .................................................................................................... A. obliquistriatus ( You et al., 1981)

– Abdominal terga with broad longitudinal stripe and pair of pale dots medially ( Fig. 12A ); penial lobes obviously divergent and with a deep U-shaped cleft between them ( Fig. 5D–E ) ..................... .................................................................................................................. A. drepanophyllus sp. nov.

Figures

Fig. 8. Mouthparts of Afronurus furcatus (Zhou & Zheng, 2003) (NNU). A. Labrum (ventral view). B. Hypopharynx (ventral view). C. Left mandible (ventral view). D. Right mandible (ventral view). E. Labium. F. Maxillae. G. Incisors of left mandible. H. Incisors of right mandible. Scale bars: A, C–D, F = 0.5 mm; B = 0.3 mm; E = 1.0 mm; G–H = 0.1 mm.

Fig. 7. Nymphal habitus of five species of Afronurus Lestage, 1924. A–C. A. furcatus (Zhou & Zheng, 2003) (NNU). D–F. A. hunanensis (Zhang & Cai, 1991) (NNU). G–I. A. obliquistriatus (You et al., 1981) (NNU). J–L. A. rubromaculatus (You et al., 1981) (NNU). M–O. A. yixingensis (Wu & You, 1986) (NNU). A, D, G, J, M. Head capsule. B, E, H, K, N. Abdominal terga. C, F, I, L, O. Caudal filaments. Scale bars: A–B, D–E, G–H, J–K, M–N = 2.0 mm; C, F, I, L, O = 1.0 mm.

Fig. 2. Mouthparts of Afronurus drepanophyllus sp. nov. (NNU). A. Labrum (ventral view). B. Median bristles of ventral labrum. C. Hypopharynx (ventral view). D. Left mandible (ventral view). E. Right mandible (ventral view). F. Labium. G. Maxillae. H. Incisors of left mandible. I. Incisors of right mandible. Scale bars: A, C–G = 0.5 mm; B = 0.3 mm; H–I = 0.2 mm.

Fig. 10. Mouthparts of Afronurus hunanensis (Zhang & Cai, 1991) (NNU). A. Labrum (ventral view). B. Hypopharynx (ventral view). C. Left mandible (ventral view). D. Right mandible (ventral view). E. Labium. F. Maxillae. G. Incisors of left mandible. H. Incisors of right mandible. Scale bars: A–D, F = 0.5 mm; E = 1.0 mm; G–H = 0.1 mm.

Fig. 1. Nymph of Afronurus drepanophyllus sp. nov. (NNU).A. Nymphal habitus. B. Selected segments, enlarged, of terminal filament and right cercus (dorsal view). Scale bars: A = 2.0 mm; B = 0.1 mm.

Fig. 3. Nymphal structures of Afronurus drepanophyllus sp. nov. (NNU). A. Foreleg. B. Midleg. C. Hindleg. D. Hindleg tibia. E. Foreleg claw. F. Gill I. G. Gill II. H. Gill VI. I. Gill VII. J. Foreleg femur, bristles on dorsal surface. Scale bars: A–C = 1.0 mm; D, F, H = 0.5 mm; E, G = 0.3 mm; I = 0.2 mm; J = 0.1 mm.

Fig. 9. Nymphal structures of Afronurus furcatus (Zhou & Zheng, 2003) (NNU). A. Foreleg. B. Midleg. C. Hindleg. D. Hindleg tibia. E. Foreleg claw. F. Gill I. G. Gill II. H. Gill VI. I. Gill VII. Scale bars: A–D = 1.0 mm; E–I = 0.3 mm.

Fig. 13. Genitalia of five species of Afronurus Lestage, 1924. A–B. A. furcatus (Zhou & Zheng, 2003) (NNU). C–D. A. hunanensis (Zhang & Cai, 1991) (NNU). E–F. A. obliquistriatus (You et al., 1981) (NNU). G–H. A. rubromaculatus (You et al., 1981) (NNU). I–J. A. yixingensis (Wu & You, 1986) (NNU). A, C, E, G, I. Genitalia. B, D, F, H, J. Penes enlarged; arrows show titillators. Scale bars: A, C, E, G, I = 0.5 mm; B, D, F, H, J = 0.2 mm.

Fig. 12. Male abdominal terga of five species of Afronurus Lestage, 1924. A. A. furcatus (Zhou & Zheng, 2003) (NNU). B. A. hunanensis (Zhang & Cai, 1991) (NNU). C. A. obliquistriatus (You et al., 1981) (NNU). D. A. rubromaculatus (You et al., 1981) (NNU). E. A. yixingensis (Wu & You, 1986) (NNU). Scale bars = 1.0 mm.

Fig. 5. Male structures of Afronurus drepanophyllus sp. nov. (NNU). A. Male imago habitus. B. Forewing. C. Hindwing. D. Genitalia. E. Penes enlarged (arrows show lobe on lateral margin and titillators, respectively). F. Male imago, showing abdominal terga. Scale bars: A = 5.0 mm; B–D = 1.0 mm; E = 0.2 mm; F = 2.0 mm.