Afronurus yixingensis ( Wu & You, 1986 )

Zhang, Wei, Lei, Zhi-Ming, Li, Wen-Juan & 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 : 111-113

Afronurus yixingensis ( Wu & You, 1986)

Figs 6F , 7M–O , 12E , 13I–J

Cinygmina yixingensis Wu & You, 1986: 280 , figs 1–13 (male, female). Types: male, female, from Jiangsu, China.

Cinygmina yixingensis – Gui 1985: 86. — Wu et al. 1986: 66, figs 23–33 (nymph). — Zhang & Cai 1991: 237. — She et al. 1995: 79. — You & Gui 1995: 53, fig. 52 (male). — Zhou & Zheng 2003: 758, figs 10, 14, 18 (adults and nymph).

Afronurus yixingensis – Braasch & Jacobus 2011: 65.

Material examined

Holotype CHINA • ♂; Jiangsu Province, Yi-Xing city, Ming-Ling village ; 31°10′5.02″ N, 119°40′17.52″ E; alt. 67 m; 15 Jul. 1980; T. Wu leg.; NNU.

Paratypes CHINA • 10 ♂♂, 2 ♂♂ subimagoes, 6 ♀♀; same collection data as for holotype; NNU .

Additional material

CHINA • 12 ♂♂ (some reared from mature nymphs), 15 ♀♀ subimagoes, 40 nymphs; Hainan Province, Chang-Jiang County, Ba-Wang-Ling National Forest Park ; 19°07′16.28″ N, 109°05′0.56″ E; alt. 304 m; 12–14 Nov. 2014; Q. Si, J.Z. Sun and J.Y. Luo leg.; NNU .

Description

Nymph

See Zhou & Zheng (2003: 758, fig. 10, first description).

Male imago

See Wu & You (1986: 280, figs 1–13, original description).

Egg ( Fig. 6F )

Ovoid, small KCTs concentrated at each pole, large KCTs and oval micropyles located equatorially.

Remarks

Among the six valid Chinese Afronurus species , A. yixingensis and A. hunanensis are separated into one group because of the similar color patterns of the head capsule in nymphs. However, as stated above for A. hunanensis , the nymphs can be separated by shape of hypopharynx, glossae, gills VII, number of comb-shaped setae on maxillae and color patterns of caudal filaments. In the male imago, they can easily be differentiated by shape of penes, titillators and projection between penial lobes.

Distribution

China (Hebei, Hubei, Hunan, Anhui, Jiangxi, Guizhou, Jiangsu, Zhejiang, Fujian, Hainan).

Ecology

Among the six Chinese Afronurus species studied in this paper, A. obliquistriatus , A. rubromaculatus and A. yixingensis are more common than the others and they are frequently found at the collecting sites. The last instar nymphs of A. obliquistriatus are recorded molting at about 10:00–12:30 AM or 17:00–19:30 PM while the last instar nymphs of A. rubromaculatus and A. yixingensis molted at about 16:00–19:00 PM local time, and these three species are observed molting underwater. The subimagoes persisted for 1–2 days and molted at 12:00–15:00 PM, the whole process lasting about 2–4 minutes. Moreover, in another observed species, A. drepanophyllus sp. nov., the last instar nymph molted at about 17:00–18:00 PM and the male subimago molted at 15:00–16:00 PM, the process lasting about 90 seconds.

Figures

Fig. 6. SEM photos of eggs. A. Afronurus drepanophyllus sp. nov. (NNU). B. A. furcatus (Zhou & Zheng, 2003) (NNU). C. A. hunanensis (Zhang & Cai, 1991) (NNU). D. A. obliquistriatus (You et al., 1981) (NNU). E. A. rubromaculatus (You et al., 1981) (NNU). F. A. yixingensis (Wu & You, 1986) (NNU).

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. 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. 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.