Afronurus drepanophyllus, Zhang & Lei & Zhou, 2021

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 : 96-100

publication ID

https://doi.org/ 10.5852/ejt.2021.767.1491

publication LSID

lsid:zoobank.org:pub:B606054C-025E-43AC-9507-14E755343A7A

DOI

https://doi.org/10.5281/zenodo.5514807

persistent identifier

https://treatment.plazi.org/id/8B78F047-E8D6-4149-9A2E-10D631959037

taxon LSID

lsid:zoobank.org:act:8B78F047-E8D6-4149-9A2E-10D631959037

treatment provided by

Felipe

scientific name

Afronurus drepanophyllus
status

sp. nov.

Afronurus drepanophyllus sp. nov.

urn:lsid:zoobank.org:act:8B78F047-E8D6-4149-9A2E-10D631959037

Figs 1–3 View Fig View Fig View Fig , 4A, D View Fig , 5 View Fig , 6A View Fig

Diagnosis

Compared to the other five Chinese Afronurus species , this new species somewhat resembles A. furcatus , A. hunanensis and A. yixingensis in imaginal stages because of their similar abdominal color patterns (with longitudinal stripes and pale dots submedially). However, these species can easily be differentiated from each other by the shape of the penes and titillators: penial lobes of A. drepanophyllus sp. nov. are obviously divergent and form a U-shaped cleft; apex of each penis diverges into three lobes; titillators are thicker and stronger than in other congeners ( Fig. 5D–E View Fig ). Comparatively, A. yixingensis has a spinelike projection between the two penial lobes and divergent spine-like titillators ( Fig. 13I–J View Fig ), while A. furcatus and A. hunanensis have plate-like titillators. Furthermore, the penial lobes of A. furcatus are slightly divergent and connected by a foliated structure ( Fig. 13A–B View Fig ). In contrast, A. hunanensis has penial lobes obviously spread out and U-shaped deeply cleft ( Fig. 13C–D View Fig ).

Generally, the nymphs of the six Chinese Afronurus species are alike because of their yellowishbrown body with various pale dots or stripes. 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 View Fig , 7A, G, J View Fig ) and without any dot ( A. hunanensis and A. yixingensis ) ( Fig. 7D, M View Fig ) (for detailed comparisons see remarks of each species below). Among the 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 View Fig ), by contrast, glossae of A. furcatus are lobe-like ( Fig. 8E View Fig ); 2) gill I is sickle-like in the new species ( Fig. 3F View Fig ) but banana-shaped in A. furcatus ( Fig. 9F View Fig ).

Compared to other Asian congeners in the genus, this new species appears to be closely related to the Thailand species A. namnaoensis Braasch & Boonsoong, 2010 in both nymphal and imaginal stages, e.g., the structures of mouthparts, legs and the shape of genitalia. However, the nymph of A. drepanophyllus sp. nov. has larger body size (6.0–8.0 mm); head capsule has 2–5 pale dots on anterior margin and 4–5 pale dots on posterior margin, respectively; abdominal terga yellowish brown and with marked pale dots on terga I–IX; gill I sickle-like; caudal filaments slightly longer than body. In contrast, the nymph of A. namnaoensis has smaller body size (4.5–6.1 mm); head capsule without distinct dot; terga yellowish and with light markings on terga VII–IX; gill I leaf-like; caudal filaments 2× length of body. In male imago, A. drepanophyllus sp. nov. has larger body size (8.0–10.0 mm); abdominal terga I–IX with brown longitudinal stripe and a pair of small pale dots medially; styliger plate with projections laterally; forceps with segment III subequal in length to segment IV and combined segments III and IV about half of segment II. Comparatively, A. namnaoensis has smaller body size (6.2–6.9 mm); terga I–IX with median stripe only; lateral margins of styliger plate slightly expanded; forceps with segment IV half of segment III in length and combined segments III and IV ⅓× length of segment II.

Etymology

The Latin specific name ‘ drepanophyllus ’ means ‘sickle’. It indicates the nymphs having sickle-like gills I.

Material examined

Holotype CHINA • ♂; Yunnan Province, Meng-La County, Meng-Lun town ; 21°56′7.12″ N, 101°14′55.72″ E; alt. 683 m; 22 Jan. 2019; X.H.Y. Zheng leg.; NNU. GoogleMaps

Paratypes CHINA • 1 ♂, 1 ♂ subimago, 1 ♀, 4 nymphs; same collection data as for holotype; NNU GoogleMaps .

Additional material

CHINA • 2 ♂♂, 50 nymphs; Yunnan Province, Liang-He County, Fen-Shui-Ling town ; 24°46′44.11″ N, 98°16′5.92″ E; alt. 951 m; 26 Apr. 2018; W. Zhang and Z.X. Ma leg.; NNU GoogleMaps .

Description

Nymph

MEASUREMENTS. Body length 6.0–8.0 mm, caudal filaments 8.0–10.0 mm long.

COLORATION. Body yellowish-brown to brown.

HEAD. Head capsule subquadrangular, anterior margin slightly thickened and with 2–5 small pale dots (some immature individuals less than 5 dots), posterior margin slightly concave; additional 4–5 pale dots located between compound eyes ( Fig. 1A View Fig ). Labrum expanded laterally, with slightly rounded apices; anterior margin with shallow median groove, long and dense setae on dorsal and ventral surfaces, those on dorsal surface longer and denser than others ( Fig. 2A–B View Fig ); an additional row of short bristles on ventral anterior margin ( Fig. 2B View Fig ). Both mandibles covered with numerous setae on outer margins; prostheca with 3–5 fimbriate bristles ( Fig. 2D–E, H–I View Fig ); outer incisor of left mandible with serrated margin and one larger terminal denticle; inner incisor shorter than outer incisor and with trifid apex ( Fig. 2D, H View Fig ); outer incisor of right mandible serrated and with 2 apical terminal denticles; inner one divided into 2 sharp denticles ( Fig. 2E, I View Fig ). Hypopharynx: apex of superlinguae strongly curved and extended into round lobelike structures, row of long hair-like setae on lateral margins from base to apex; lingua bell-like, subequal to superlinguae in length and with tuft of setae at apex ( Fig. 2C View Fig ). Maxillae with scattered fimbriate setae on ventral surface ( Figs 2G View Fig , 4D View Fig ), row of 13–15 comb-shaped setae on crown of galea-lacinia, middle combs with 9–13 teeth, distal dentisetae branched, proximal dentisetae bifid and fringed ( Fig. 4A View Fig ); maxillary palpi 3-segmented, first segment with setae on outer margin and basal half of inner margin; second segment obviously longer than basal one, outer margin with long setae, terminal segment with dense setaceous brush ( Fig. 2G View Fig ). Labium: slightly oblong, inner margins of glossae slightly expanded and with tuft of long setae; paraglossae expanded greatly into palpable lobes, with dense setae and bristles on dorsal and anterior margins; labial palpi broad, 2-segmented; ventral surface and free margin with setae brushes; dorsal surface with setae ( Fig. 2F View Fig ).

THORAX. Pronotum slightly extended laterally, subequal to head in width ( Fig. 1A–B View Fig ). Supracoxal spurs rounded. Femora of all legs with long setae on outer margins, dorsal surfaces and inner margins with two kinds of spatulate setae, the shorter setae more abundant than longer ones ( Fig. 3J View Fig ). Foretibia subequal in length to femur, base of outer margin with sparse hair-like setae ( Fig. 3A View Fig ), dorsal surface with rows of fine setae and bristles, inner margin with row of bristles only; foretarsi slightly shorter than ⅓ tibia, outer and inner margins with tiny setae. Midleg similar to foreleg, except tibia 0.7× length of femur, with row of hair-like setae on outer margin ( Fig. 3B View Fig ). Hindleg similar to midleg except tibia 0.65× length of femur, outer margin with rows of dense hair-like setae and bristles, dorsal surface with short and long bristles ( Fig. 3C–D View Fig ). Claws of all legs with 3–4 subapical denticles ( Fig. 3E View Fig ).

ABDOMEN. Abdominal terga I–II pale, terga III–VII brown with 2 median pale dots and 2 lateral dots; pale dots on terga IV–V fused together and forming pale stripes; terga VIII–IX with fused pale dots and tergum VIII always with longitudinal brown stripe medially; tergum X dark brown ( Fig. 1A View Fig ); posterolateral angles of terga III–VII extended into small acute projections. Gill I sickle-like, inner margin slightly curved ( Fig. 3F View Fig ); gills II–VI heart-like and lamellae expanded laterally ( Fig. 3G View Fig ), gills V–VI with apical arrow-like accessory lobes ( Fig. 3H View Fig ); gill VII round, with fine marginal setae, appreciably asymmetrical ( Fig. 3I View Fig ). Basal of caudal filaments pale and other parts yellowish brown, with whorled spines on articulations ( Fig. 1A–B View Fig ).

Male imago

MEASUREMENTS. Body length 8.0–10.0 mm, forewing 8.0–10.0 mm, hindwing 2.0–3.0 mm, cerci 19.0– 22.0 mm long. Compound eyes contiguous, upper portion hoar and lower portion dark blue.

COLORATION. Body generally pale to yellowish ( Fig. 5A, 5F View Fig ).

THORAX. Mesonotum with apparent transverse suture, and medial depression of furcasternum parallel. Foreleg: length of femur 3.0 mm, length of tibia 3.5 mm, length of tarsi 4.5 mm, tarsal segments from basal to apical = 0.9:1.4:1.2:0.6:0.4. Midleg: length of femur 2.0 mm, length of tibia 1.3 mm, length of tarsi 1.0 mm, tarsal segments arranged in decreasing order as 1, 5, 2, 3, 4. Hindleg: length of femur 2.0 mm, length of tibia 1.5 mm, length of tarsi 0.8 mm, tarsal segments arranged in decreasing order as 5, 1, 2, 3, 4. All claws of legs similar, one blunt and one hooked. Forewing hyaline, costal, subcostal and R 1 fields semitransparent; Rs and MP forked at same level at wing base, MA forked at over ½ of distance from base of wing to margin ( Fig. 5B View Fig ). Hindwing transparent, with costal projection at base, MA forked in middle, MP forked much more basally than MA ( Fig. 5C View Fig ).

ABDOMEN. Pale but with a longitudinal light brown stripe medially, terga I–VII with pair of pale dots, posterior margin of each tergum with dark brown stripe ( Fig. 5F View Fig ).

GENITALIA. Posterior margin of styliger plate convex, lateral margins with two distinct lobes ( Fig. 5D– E View Fig ). Forceps of segment III subequal to those of segment IV in length, combined segments III–IV approximately half length of segment II. Penial lobes divergent and with U-shaped cleft between them; apices of penial lobes divided into three parts or apices, the median one much broader than inner and outer lobes. Robust but blunt titillators at base of penes, covered by styliger plate and invisible in ventral view ( Fig. 5D–E View Fig ). Cerci pale with dense tiny setae on surface and brown dots on articulations.

Egg

Oval, chorion decorated with small KCTs at poles, large KCTs located equatorially ( Fig. 6A View Fig ).

Distribution

China (Yunnan, Guizhou, Zhejiang, Guangxi).

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