Cloeon sidadi, Soldán, Tomáš & Bojková, Jindřiška, 2015

Soldán, Tomáš & Bojková, Jindřiška, 2015, New species of mayflies (Ephemeroptera) from Cape Verde, Zootaxa 3926 (4), pp. 561-575 : 567-571

Cloeon sidadi sp. n.

Male imago. Not known.

Female imago. Length: body 4.5–5.2 mm; forewings 5.7–6.1 mm; cerci 8.1–10.0 mm.

Head. Whitish, dorsally with pair of conspicuous, submedial, dark red stripes and pair of narrow dark red stripes laterally ( Fig. 5 A, B). Eyes greyish, slightly olive-green, with paler longitudinal band in middle ( Fig. 5 B). Distance between compound eyes three times wider than eye width. Scape and pedicel whitish, with sharp brownish red markings; flagellum yellowish, unicoloured.

Thorax. Pronotum whitish, with two submedial longitudinal dark red stripes and wide brownish lateral stripes bordered by dark red stripes along both sides ( Fig. 5 A, B). Mesonotum whitish yellow, medial area with two brown stripes and one interrupted dark red stripe in the middle; dark red markings at wing bases and distal and proximal margins. Metanotum light brown, tinted with violet. Pleural part of thorax pale, sometimes with diffuse violet spots near bases of coxae.

Forewings translucent (except vitta); venation light brown, only cross veins in vitta white or conspicuously white bordered. Pterostigma with 2–3 cross veins. Costal field translucent, except brown-tinted area along basal part of subcostal vein; subcostal field brown, same colour from base to apex of wing ( Fig. 5 A). Costal area with 1–2 cross veins. Several cross veins near posterior margin of wing.

Legs whitish yellow; distal part of fore femora and basal part of tibiae with conspicuous dark red oblique stripes; middle and hind legs unicoloured, except for diffuse dark red spots on coxae; both claws of all legs brownish. In some specimens, all of fore femoral surface tinted with brownish red. Second segment of hind tarsus twice as long as third segment.

Abdomen. Terga intensely dark red with two wide whitish longitudinal bands in middle ( Fig. 5 A). Sterna pale, without markings.

Cerci white, with 8–9 intense violet-brown rings near bases.

Male subimago. Head. Yellowish brown; antennae light brown, unicoloured. Turbinate eyes orange ( Fig. 5 C), asymmetric in dorsal view, with nearly straight inner margin and rounded outer margin; lateral eyes greyish-black.

Thorax. Pronotum and mesonotum whitish, with brown longitudinal markings ( Fig. 5 C). Metanotum whitish, unicoloured.

Forewings milky, veins of same colour, except for darker vein Sc. Legs greyish, unicoloured, without markings.

Abdomen. Terga greyish, unicoloured, without markings. Sterna pale. Cerci greyish.

Female subimago. Head. Whitish, dorsally with pair of conspicuous, submedial, dark red stripes paler than in female imago. Eyes light greyish. Scape and pedicel tinted brownish; flagellum light brownish, unicoloured.

Thorax. Pronotum yellowish-brown, longitudinal bands apparent, but diffuse. Mesonotum yellowish brown with darker bands. Metanotum light brown, paler in middle. Pleural part of thorax pale.

Forewings milky, unicoloured; venation milky; colouration of vitta not apparent.

Legs yellowish brown, unicoloured, imaginal markings not apparent.

Abdomen. Terga with markings resembling female imago, but lighter brown and more diffuse. Sterna pale, without markings.

Cerci whitish yellow; rings less apparent than in imago.

Larva. Male larva length: 4.4–5.1 mm, cerci: 3.0 mm; female larva length: 4.7–5.4 mm, cerci: 3.1–3.3 mm.

Head. Light brown, with epicranial suture yellowish bordered ( Fig. 5 D), in some specimens further yellowish elongated spots near lateral eyes and on genae. Turbinate eyes light brownish; lateral eyes black. Scape 1.3 times longer than pedicle.

Mouthparts. Dorsal surface of labrum ( Fig. 6 A) covered with long pointed setae; ventral surface with submarginal row of 8–9 stout pointed setae; distal margin bordered with long feathered setae; setae along lateral margin long and simple.

Hypopharynx ( Fig. 6 B) with lingua rounded with distinguishable apex, densely covered by setae; superlinguae longer than lingua, rounded and densely covered by long marginal setae.

Right mandible ( Fig. 6 C) with two groups of incisors, inner with three rounded teeth and outer with four blunt teeth; prostheca asymmetric, with finger-like apex bent inside and three small teeth. Sparse tuft of long setae between prostheca and mola; outer margin of mandible distinctly convex. Left mandible ( Fig. 6 D) with two welldivided groups of incisors; outer group with four blunt teeth, outer tooth distinctly shorter than remaining ones; inner group with four rounded teeth, two long and finger-like and two short and wide; left prostheca comb-shaped with three long sharply pointed projections on inner side. Dense tuft of long setae between prostheca and mola.

Maxillae ( Fig. 6 E) with three hooked teeth and dorsal row of subequal setae of medium length and ventral row of spine-like setae. Palps three-segmented; segment I approximately 0.8x length of segments II and III combined; segment II approximately 1.5x length of segment III. Surface of segments II and III sparsely populated with long and fine setae; apex of segment III with terminal seta with wide base.

Labium ( Fig. 6 F) with glossae and paraglossae of comparable length; margins of glossae with stout pointed setae, median part of glossae with 20–30 long and pointed setae. Paraglossae dorsally and ventrally with row of 7–8 long and stout setae parallel to inner margin, row of long and pointed setae along outer margin (apical ones longest and stout), four long and pointed setae medially in apical part of paraglossae and scattered fine setae at lower part of paraglossae. Labial palps three-segmented; segment I approximately 0.6x length of segments II and III combined; segment II approximately 1.1x length of segment III. Segment III tapered (ratio length/width =1.7), with concave inner margin bearing row of long setae and with irregular row of stout and pointed setae submarginally. Segment II with 5–6 subapical stout setae.

Thorax. Pronotum light brown, with light median line and two pairs of large diffuse yellowish white spots ( Fig. 5 D). Mesonotum light brown, with three pairs of conspicuous submedian yellowish white spots, pale posterior margins and large spots near base of wing pads. Pleural part of thorax brownish, without markings except for darker posterolateral parts of coxae. Femora whitish yellow with darker diffuse subapical band; tibiae slightly darker near bases; tarsi slightly darker near apex.

Forelegs. Dorsal surface of femora with row of stout pointed spines along front and hind margin, and similar pointed spines scattered on proximal half of femora ( Fig. 7 D). Dorsoapical patch composed of three spine-like setae. Tibiae and tarsi almost bare dorsally, only with stout and pointed spines along hind margin. Subproximal arc of thin setae on tibiae absent. Tarsal claws slender and relatively long (0.4 x length of tarsi) with two rows of about 18 acute teeth increasing in length towards apex.

Abdomen. Terga with pairs of conspicuous spots ( Fig. 5 D). Spots small on segments I–V, large and most conspicuous on segments VI and VII, diffuse or missing on segments VIII–X (Fig. 10C). Posterior margins of abdominal terga with teeth of three sizes and shapes: elongate, relatively narrow teeth and about one third shorter teeth irregularly alternating with elongated short teeth ( Fig. 4 B). Six or seven spines on segment VIII and eight or nine spines on segment IX; other segments with only anterolateral teeth (Fig, 4D). Sterna whitish yellow, without markings.

Gills on segments I–VI with two lamellae. Dorsal lamella of gill I tongue-shaped, slightly shorter than ventral lamella; ventral lamella nearly symmetric, circular, clearly wider than long ( Fig. 7 A). Dorsal lamella of gill III asymmetric; ovoid, clearly wider than long ( Fig. 7 B). Gill VII single, almost symmetric, with parallel lateral margins and rounded outer margin ( Fig. 7 C).

Cerci and paracercus slightly longer than abdomen, yellow, posterior part slightly darker, brown rings on each fourth segment apparent. Cerci with abundant thin setae on inner margins.

Type material. Holotype: female imago reared from larva; Santiago, unnamed irrigation cistern, Cidade Velha; 14°55'22.0'' N / 23°36'06.8'' W; 40 m a.s.l.; 17.v.2013.

Paratypes: 3 male subimagines, 68 female imagines, 9 female subimagines, 81 larvae; same data as holotype.

Etymology. The species was named after quaint little town of Cidade Velha ( Sidadi in Cape Verdean Creole language) where it was collected. This town is the oldest settlement in Cape Verde and the first European colonial outpost in the tropics.

Biology. Larvae were collected only in two concrete cisterns ( Fig. 8 D) that stored water for irrigation of sugarcane fields and plantations of tropical fruits in the canyon of Ribeira Grande (dry in May). Cloeon sidadi sp. n. seems to be at high risk of extinction because the irrigation system in the valley of Ribeira Grande is closed, and the few open cisterns are regularly drained which regularly destroys a part of the persisting population. We observed other open cisterns only in the valley of São Jorge dos Orgãos, where no mayflies were collected. Cisterns in Ribeira Grande seemed to be the last refugium for aquatic insects during the dry season, because these insects occurred in high abundance there. We observed numerous individuals of the whirligig beetle Dineutus aereus , the water scavenger beetle Sternolophus solieri Laporte de Castelnau, 1840, the diving beetle Hyphydrus sp., the backswimmer Anisops sp. and several species of semiaquatic bugs ( Veliidae and Mesoveliidae ).

Figures

FIGURE 4. Distal margin of abdominal tergum IV (scale bar 0.05 mm): A— Cloeon morna sp. n.; B— Cloeon sidadi sp. n. Lateral margin of abdominal terga VIII and IX: C— Cloeon morna sp. n.; D— Cloeon sidadi sp. n.

FIGURE 5. Cloeon sidadi sp. n.: A—female imago; B—head and thorax of female imago; C—head and thorax of male subimago; D—larva.

FIGURE 6. Cloeon sidadi sp. n., mouthparts: A—labrum (left ventral view, right dorsal view); B—hypopharynx; C—right mandible; D—left mandible; E—right maxilla; F—labium.

FIGURE 7. Cloeon sidadi sp. n., larva: A—gill I; B—gill III; C—gill VII; D—fore leg.

FIGURE 8. Aquatic habitats in the islands of Santo Antão and Santiago. A—Ribeira da Torre in Xôxô (type locality of Cloeon morna sp. n.); B—pools of Ribeira Tarrafal in Tarrafal de Monte Trigo; C—irrigation system of taro fields common in Santo Antão; D—irrigation cistern in the valley of Ribeira Grande in Cidade Velha (type locality of Cloeon sidadi sp. n.); and E—an unnamed brook in Fontainhas.