Susua niandanensis (Wuillot in Wuillot & Gillies 1993 )

Kluge, Nikita J., Gattolliat, Jean-Luc, Salles, Frederico F. & Novikova, Eugenia A., 2018, Revision of the Afrotropical genus Susua Lugo-Ortiz & McCafferty 1998 (Ephemeroptera: Baetidae: Protopatellata), Zootaxa 4434 (1), pp. 1-28 : 17-26

Susua niandanensis (Wuillot in Wuillot & Gillies 1993)

( Figs 62–110 )

Afroptilum niandanensis Wuillot in Wuillot & Gillies 1993b: 272 (♂ imago and larva).

Susua niandanensis: Lugo-Ortiz & McCafferty 1998: 24 .

Material examined. Topotypes: GUINEA, Niger, Sassambaya, Niandan, 23.XII.1984, coll. J.-M. Elouard: 13 larvae (QR code GBIFCH00238432); same locality and collector, 23.XII.1985: 13 larvae (QR code GBIFCH00238437); 19.IV.1986: 30 larvae (QR code GBIFCH00238439); 6.IV.1988: 3 larvae (QR code GBIFCH00238436). Other localities: MALI, Sénégal, Missira, Baoule, 08.XI.1984, coll. J.-M. Elouard: 1 larva (QR code GBIFCH00238434). SENEGAL, Gambia, Mako, Gambia, 26.I.1989, coll. J.-M. Elouard: 2 larvae (QR code GBIFCH00238431). CÔTE D'IVOIRE: Cavally, Tai, Cavally, 10.II.1988, coll. J.-M. Elouard: 6 I ♂ (QR code GBIFCH00238435); Cavally, Tai, N'ze, 10.II.1988, coll. J.-M. Elouard: 8 I ♂ (QR code GBIFCH00238433); Anoblekro, Soumié, 1.VII.2003, coll. Edia Oi Edia: 1 larva (QR code GBIFCH00521576); Anoblekro, Soumié, 6.III.2005, coll. Edia Oi Edia: 1 larva (QR code GBIFCH00521577). ZAMBIA: River West Lunga and River Mudanyama near Mwinilunga, 14–17.VIII.2014, coll. N. Kluge & L. Sheyko: 1 L-S-I ♀ {number [XI](9)C}, 1 L/ S ♂, 1 larva ( ZIN); River Lwakela 22 km N Mwinilunga, 16–21.VIII.2014, coll. N. Kluge & L. Sheyko: 1 L/S ♀, 1 larva ( ZIN); River Zambezi upstream Victoria Falls, 25–31.VIII.2014, coll. N. Kluge & L. Sheyko: 2 larvae ( ZIN).

Descriptions. Larva. CUTICULAR COLORATION. Head with brown and colorless areas; area between eyes brown with contrasting blanks at places of muscle attachments ( Fig. 65 ). Pronotum and mesonotum with brown and colorless areas; fore protoptera light, with narrow contrasting dark stripes along convex veins ( Figs 78–80, 82 ). Metanotum brown with lighter areas; hind protoptera dark at base, colorless in most part ( Fig. 83 ). Thoracic pleura brown ( Fig. 78 ), sterna colorless. Legs partly colorless, with two interrupted diffusive brown cross bands on femur, diffusive brown band on patella and diffusive brown transverse band crossing apex of tibia and base of tarsus ( Figs 78 , 91–93 ). Abdominal coloration varying from contrasting, with dark brown markings occupying most part of terga II–VI and IX ( Fig. 78 ) to nearly colorless, with contrasting brown spot at middle of tergum III and at middle of tergum VI. Cerci and paracercus partly colorless with brown cross band at middle and brown apices; on light portions of cerci and paracercus swimming setae also light; on brown bands each swimming seta brown proximally, colorless distally ( Figs 79, 81 ).

HYPODERMAL COLORATION. Thorax and abdomen, besides brown cuticular coloration, with red, purple or orange hypodermal markings varying individually ( Figs 82–86 ).

STRUCTURE. Larval head and mouthparts as characterized above [see Crassabwa /g1 (1), (7)–(11) and diagnosis of Susua ]. Labrum with a deep apicomedial emargination ( Fig. 65 ). Labium with contrasting brown sclerites on mentum: ventral T-shape sclerite ( Figs 62–63 ), pair of lateral sclerites bearing bases of paraglossal muscles ( Fig. 63 ) and pair of dorso-lateral sclerites ( Fig. 64 ); labial palp with 3rd segment elongate and conic ( Figs 62 , 69 ; Wuillot & Gillies 1993b: Fig. 20 ); musculature as characterized for Susua (as in Fig. 5 ).

Head, pronotum and mesonotum without seta-like scales: scales on pronotum short and blunt ( Fig. 88 ), setae on mesonotum partly short and blunt, partly stretched apically ( Fig. 89 ); fore protoptera with short, blunt scales ( Fig. 90 ). In contrast to S. sigiensis , bunches of spatulate setae absent. Mesonotum without unpaired ridge ( Fig. 78 ) (in contrast to S. sigiensis ). Hind protoptera equally developed in both sexes ( Fig. 83 ). Legs as characterized above [see Crassabwa /g1 (2)–(4), (12)–(14)], markedly thickened; width of femur greatly varies individually ( Figs 91– 92 ).

Abdominal terga with numerous scales in wide sockets, varying from short and blunt to long and pointed ( Figs 94–95 ). Posterior margin of postnotum and one or several most anterior abdominal terga without denticles, with the same scales as on other surface ( Fig. 94 ); posterior margin of other abdominal terga, up to tergum X, with such scales irregularly alternating with pointed denticles ( Fig. 95 ); at middle of posterior margin of tergum IX (behind submedian pair of setae) denticles either slightly diminished, or indistinguishable from others, never interrupted. Latero-posterior angles of abdominal terga II–X with several large pointed denticles. Abdominal sterna with short, blunt scales and short fine setae not forming rows ( Fig. 95 ). Posterior margin of sterna I–VII without denticles, posterior margins of sterna VII–IX with pointed denticles ( Fig. 95 ). Paraprocts with pointed denticles ( Fig. 77 ). Tergalius I very long, petiolate, with costal and anal ribs thin and present only in proximal part, with distal part widened and not bordered by ribs ( Fig. 72 ). Each tergalius II–VII with long costal and anal ribs on costal and anal margins, only distal margin not bordered by rib; both costal and anal ribs deeply serratulate; tergalii II–IV of equal size and shape ( Fig. 73 ), tergalii V–VII gradually smaller ( Figs 74–76 ). Cerci with small denticles on lateral sides of all segments; outer side of cercus with few small setae.

RESPIRATORY MOVEMENTS. Larva makes rhythmical movements by tergalii of first pair (which are greatly enlarged—Fig. 72), while other tergalii do not make respiratory movements.

Subimago. CUTICULAR COLORATION. Head colorless. Pronotum nearly colorless. Mesonotum nearly colorless, certain sutures brown ( Fig. 101 ). Thoracic pleura and sterna at most part nearly colorless, certain sclerites brown ( Fig. 102 ). Legs nearly colorless with brown microtrichia. Abdominal terga and sterna nearly colorless with brown microtrichia. Cerci colorless with brown spines.

TEXTURE. On all legs of male and female all tarsomeres covered by pointed microlepides.

Imago. Head of female dorsally ocher with brown markings ( Figs 103–104 ). Mesonotum with low and shallow median ridge ( Fig. 104 ) (in contrast to S. sigiensis ). In female thorax ocher with brownish, with equally colored dorsal, ventral and lateral sides ( Figs 103–104 ). In both sexes, on middle and hind leg tibia with innerapical projection, tarsus with large apical spines on 1 st and 2nd tarsomere (primary 1st+2nd and 3rd tarsomeres); smaller spine on 3rd tarsomere (primary 4th tarsomere) present ( Fig. 100 ) or absent. In both sexes, fore wing with membrane and veins colorless; pterostigma with 4–7 simple oblique veins; hind wings narrow, with fore margin nearly straight and hind margin slightly convex, apex pointed, 2 longitudinal veins, hooked costal projection ( Figs 71 , 106 ). Both in male and female hypodermal coloration of abdomen varies from intensive red markings ( Figs 84, 86 ) to nearly colorless with few spots ( Fig 85 ).

Gonostyli: 1 st segment elongate, 2nd segment widened apically, 3rd segment elongate and clavate ( Fig. 107 ; Wuillot & Gillies 1993: Fig. 16 ). Each gonovectis apically pointed and shallowly bent S-like; proximally without projection, so gonovectal muscle attached directly to smooth margin of gonovectis ( Figs 98 , 108 ).

Eggs. Irregular oval, 0.15 mm length; chorion with irregular longitudinal ridges consisted of fused protuberances ( Figs 109–110 ).

Dimension. Fore wing length of examined female imago 5 mm; according to Wuillot & Gillies (1993b), fore wing length of male 3–4 mm.

Distribution. Afrotropical Region (known from Guinea, Senegal, Côte d'Ivoire and Zambia)

Figures

FIGURES 62–68. Last instar larvae of Susua niandanensis from Zambia. 62, exuviae of labium; 63, base of labium with focus on ventral side; 64, the same with focus on dorsal side; 65, detached cuticle of mle head with labrum, mandibles and bases of antennae (with subimaginal antennae inside); 66, apex of maxilla (with focus on dentisetae and inner-dorsal row of setae); 67– 68, left and right mandibles. Abbreviation: d-l, dorso-lateral sclerite.

FIGURES 69–77. Susua niandanensis from Zambia. 69, labium (at left ventral view; at right dorsal view); 70, larval claw; 71, hind wing of female imago (interrupted line shows lost part of costal projection); 72–73, tergalii I–II; 74–76, tergalii V–VII; 77, paraproct.

FIGURES 78–86. Susua niandanensis from Zambia. 78–79, male larva of last instar; 80–81, exuviae of last instar female larva (80, right half of pronotum and mesonotum; 81, abdominal sterna, terga and caudalii); 82–84, parts of last instar male larva (82, pronotum and mesonotum; 83, metanotum; 84, abdomen); 85, subimaginal abdominal sterna and terga extracted from mature male larva; 86, abdominal terga and sterna of female imago (the same specimen as in Figs 80–81). Abbreviations: I–X, abdominal segments I–X.

FIGURES 87–90. Exuviae of left half of pronotum and mesonotum of last instar larva of Susua niandanensis from Zambia. 87, general view; 88, scales on pronotum; 89, scales on mesonotum; 90, scales on posterior part of fore protopteron.

FIGURES 91–96. Susua niandanensis. 91–92, hind femora of two specimens from Guinea (type locality); 93–95, exuviae of last instar larva from Zambia: 93, hind leg (black triangle shows point where patella-tibial suture crosses inner margin); 94, tergum V; 95, tergum VII; 96, sternum IX.

FIGURES 97–104. Susua niandanensis from Zambia. 97, folded subimaginal genital extracted from larva; 98, detail of 97 with focus on left gonovectis; 99–100, fore and middle legs of female imago; 101, subimaginal exuviae of right half of mesonotum; 102, subimaginal exuviae of left pleuron; 103–104, head and thorax of female imago. Abbreviations: gd, gonoduct; gv, gonovectis; m.gs, gonostylar muscle; m.gv, gonovectal muscle; m.s, styligeral muscle; pat, patella-tibial suture.

FIGURES 105–108. Susua niandanensis from Côte d’Ivoire. 105, fore and hind wings; 106, hind wing; 107, genitals of male imago, ventral view (gonovectes shown by interrupted lines); 108, penis of male imago with focus on right gonovectis and gonovectal muscle.

FIGURES 109–110. Egg of Susua niandanensis from Zambia.

FIGURES 17–27. Larva of Susua sigiensis. 17, base of tibia of fore leg, anterior view (setae on posterior side shown by interrupted lines); 18, apex of femur and base of tibia of middle leg, anterior view (setae on posterior side shown by interrupted lines); 19, claw; 20–26, tergalii I–VII; 27, paraproct.

FIGURES 5–9. Larva of Susua sigiensis. 5, labium (at left ventral view with muscles of glossa, paraglossa and palp shown by interrupted lines; at right dorsal view); 6, labrum (dorsal view); 7, apex of left maxilla; 8–9, biting edges of left and right mandibles. Abbreviations: ds1, ds2, ds3, dentisetae.

FIGURES 10–16. Exuviae of last instar larvae of Susua sigiensis. 10, caudalii; 11, right half of pronotum and mesonotum; 12, abdominal sterna, terga and caudalii; 13, fore leg; 14, middle leg with meso- and metathoracic pleura, half of metanotum and hind protopteron; 15, hind leg; 16, labium. Abbreviations: I–X, abdominal segments I–X; ppt, hind protopteron. Black triangle shows point where patella-tibial suture crosses inner margin.