Susua Lugo-Ortiz & McCafferty 1998

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 : 5

Genus Susua Lugo-Ortiz & McCafferty 1998

( Figs 1–110 )

Susua Lugo-Ortiz & McCafferty 1998: 24 .

Type species Afroptilum niandanensis Wuillot in Wuillot & Gillies 1993b .

Diagnosis. Tergalius I is sharply different from others, petiolate, i.e. narrow in proximal part and widened in distal part ( Figs 20 , 41 , 72 ). The same in Dabulamanzia and Cheleocloeon , but not in Crassabwa , whose tergalius I is wide in proximal part, but is bent in such a way that looks like petiolate ( Kluge et al. 2017: Figs 13 , 84 ). Each tergalius I–VII with costal and anal ribs on costal and anal margins, with distal margin not bordered by rib ( Figs 20–26 , 72–76 ).

At least tergalii II–VII are unable for rhythmical respiratory movements: in S. niandanensis only tergalii of 1 st pair make respiratory movements, in S. sigiensis all tergalii are unable for respiratory movements.

Cuticular coloration of abdominal terga is similar in both species: cuticle of terga VII–VIII and X either colorless, or with brown pigmentation less intensive than on terga III–VI and IX ( Figs 3 , 12 , 79, 81 ).

Maxillary palp 2-segmented, with 2nd segment very soft and delicate ( Wuillot & Gillies 1993b: Fig. 21 ) (in contrast to Crassabwa , whose 2nd segment is widened).

Muscle-abductor of 2nd segment of labial palp is attached at base of submentum ( Fig. 5 ) [in contrast to Crassabwa , where it is attached at median groove of submentum ( Kluge et al. 2017: Fig. 5 )].

Larval abdominal terga II–VI either without denticles, or with irregular denticles alternating with scales ( Fig. 37 ) [in contrast to Crassabwa , whose abdominal terga I–X have regular row of pointed denticles on posterior margin ( Kluge et al. 2017: Fig. 20 )].

Larval cerci with small denticles on lateral sides of all segments ( Fig. 10 ) (in contrast to Crassabwa , whose cerci and paracercus have prominent denticles enlarged on each 2nd segment).

Postsubalar sclerite has posterior-dorsal corner stretched to a process with convex dorsal margin ( Figs 49 , 102 ). The same in many other taxa, but in contrast to Crassabwa , whose posterior-dorsal process is thinner, with concave dorsal margin ( Kluge et al. 2017: Figs 36 , 98 ). Postsubalare has the same shape in imago and subimago, being well visible on subimaginal exuviae due to contrasting cuticular coloration.

Composition. The genus Susua includes two species, S. sigiensis ( Gillies 2001) and S. niandanensis (Wuillot in Wuillot & Gillies 1993) . Two species which Salles, Gattolliat & Sartori (2016) reported as «aff. Susua sp. 1» and «aff. Susua sp. 2», were subsequently moved to the genus Crassabwa and described as Crassabwa ameliae Kluge et al. 2017 and C. ludmilae Kluge et al. 2017 correspondingly (see below).

Figures

FIGURES 1–4. Holotype of Susua sigiensis: 1, dorsal view; 2–3, genitalia; 4, larval exuviae.

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.

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 28–33. Exuviae of left half of pronotum and mesonotum of last instar larva of Susua sigiensis. 28, general view; 29–31, bunches of spatulate setae on places shown by arrows; 32, scales on pronotum; 33, scales on posterior part of fore protopteron.

FIGURES 34–40. Exuviae of abdomen of last instar larva of Susua sigiensis. 34, tergum I; 35, tergum II; 36, tergum V; 37, tergum VIII; 38, tergum IX (black triangle shows midline); 39, tergum X; 40, sternum VII.

FIGURES 41–46. Susua sigiensis. 41, anterior part of larva; 42, anterior part of female imago; 43–44, hind leg of imago and its subimaginal exuviae; 45–46, the same of another specimen. Abbreviations: R, unpaired median ridge on mesonotum; S, paired bunches of spatulate setae on pronotum and mesonotum.

FIGURES 47–51. Susua sigiensis. 47–48, female imago, dorsal and ventral view; 49, subimaginal exuviae of left pleuron; 50, male imago; 51, male imago with subimaginal exuviae.

FIGURES 52–57. Susua sigiensis. 52, hind wing; 53, penis, ventral view; 54–55, genitals of male imago and its subimaginal exuviae, ventral view; 56, genitals of another specimen (penis dotted, its hidden parts shown by interrupted lines; median styligeral muscle, gonovectal muscles and right gonostylar muscle shown by interrupted lines; areas of anterior attachment of median paraproctal muscles shown by dotted lines); 57, subimaginal genitals developing under larval cuticle. Abbreviations: gs1, gs2, gs3, 1st–3rd segments of gonostylus; usg, unistyliger.

FIGURES 58–61. Eggs of Susua sigiensis.

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.