A contribution to the genus Afronurus Lestage, 1924 in China (Ephemeroptera: Heptageniidae, Ecdyonurinae)

Wei Zhang,Zhi-Ming Lei,Chang-Fa Zhou,Wen-Juan Li

doi:10.5852/ejt.2021.767.1491

Abstract

The genus Afronurus has several very common mayfly species in China and they are widely distributed in this country. Some of them are quite similar to each other in both imaginal and nymphal stages. However, these species have not been systematically compared and reviewed so far. In this study, six species are recognized. All nymphs of them share the following characters: gills V–VI with additional arrow-like accessory lobes, branched dentisetae, two rows of bristles and setae on hindtibiae and spotted abdominal terga. The males have divergent penes and clearly expressed titillators. The nymphs of the new species A. drepanophyllus sp. nov. have sickle-like gills I, spotted and striped body color, and males have unique genitalia. The nymphal stages of A. furcatus and A. hunanensis, which are associated and described for the first time, have similar body color to A. drepanophyllus sp. nov., but their pale dots on the head capsules and the shape of the hypopharynx are different. Keys to males and nymphs of the six species are provided.

Highlights

The mayfly genus Afronurus Lestage, 1924 was first established for the species Ecdyonurus peringueyi Esben-Petersen, 1913 based on male and female imagoes from South Africa
For the convenience of identification, we separate them into two groups here: anterior margin of head with pale dots (A. drepanophyllus sp. nov., A. furcatus, A. obliquistriatus and A. rubromaculatus) (Figs 1A, 7A, G, J) and without any dot (A. hunanensis and A. yixingensis) (Fig. 7D, M)
Among the ZHANG W. et al, Six species of the genus Afronurus from China first group, A. drepanophyllus sp. nov. and A. furcatus can be identified by the following characters: 1) glossae of the new species are slightly oblong (Fig. 2F), by contrast, glossae of A. furcatus are lobe-like (Fig. 8E); 2) gill I is sickle-like in the new species (Fig. 3F) but banana-shaped in A. furcatus (Fig. 9F)

Summary

Introduction

The mayfly genus Afronurus Lestage, 1924 was first established for the species Ecdyonurus peringueyi Esben-Petersen, 1913 based on male and female imagoes from South Africa. The genus Cinygmina, which contains 24 Asian species, was recognized as the Afronurus assamensis group based on morphology, egg structures and zoogeography by Braasch & Boonsoong (2010), Braasch (2011) and Braasch & Jacobus (2011). In China, 18 species under the name of Afronurus or Cinygmina have been reported (You et al 1981; Wu & You 1986; Wu et al 1986; You 1987; Zhang & Cai 1991; Kang & Yang 1994; Zhou & Zheng 2003; Braasch & Jacobus 2011; Sartori 2014). The male imagoes have titillators, which has been inferred by Braasch & Jacobus (2011) and considered as the main character of the Afronurus assamensis group (= Cinygmina) in Asia. The egg structures have small KCTs at the poles and large KCTs located equatorially, which is consistent with the theories of Belfiore et al (2003), Kluge (2004) and Webb & McCafferty (2008)

Material and methods

Results

Discussion