Cloeodes danta Vasquez-Bolanos , Sibaja-Araya & Guevara-Mora, 2020

Vasquez-Bolanos, Oscar, Sibaja-Araya, Fabian & Guevara-Mora, Meyer, 2020, New species and records of Cloeodes Traver, 1938 (Ephemeroptera, Baetidae) from Costa Rica, ZooKeys 989, pp. 55-72 : 55

Cloeodes danta Vasquez-Bolanos, Sibaja-Araya & Guevara-Mora sp. nov. Figures 2 , 3 , 4 , 5 , 6

Material examined.

Holotype: mature ♂ nymph slide-mounted in Euparal, Costa Rica, Heredia Province, Central Volcanic Mountain Range, Cerro Chompipe zone, Refugio de Vida Silvestre Cerro Dantas, Río Las Vueltas, 10°5'38.24"N, 84°3'42.57"W, 2000 m above sea level, VI/09/2017, Sibaja-Araya F. and Acuña F. (colls), deposited in Museo de Nacional de Costa Rica, San José Province. Paratypes: 5 mature nymphs same data as holotype, preserved in 95% alcohol (mouthparts, legs, gills, terga and paraprocts in micro-vial) deposited at Laboratorio de Entomología (LEUNA), Escuela de Ciencias Biológicas, Universidad Nacional, Heredia (1♂, 1♀); Museo de Zoología, Universidad de Costa Rica (1♀) and PERC, West Lafayette, Indiana, USA (1♂, 1♀).

Additional material.

Nine nymphs, Quebrada Grande, Refugio de Vida Silvestre Cerro Dantas, 10°5'38.24"N, 84°3'42.57"W, about 1 km from the Río Las Vueltas at 2054 m asl, where type material was collected, Heredia Province, Costa Rica V/13/2018, F. Sibaja, D. Romero, M. Guevara, D. Segura, O. Vásquez (colls), deposited at Laboratorio de Entomología (LEUNA) of the Escuela de Ciencias Biológicas, Universidad Nacional.

Diagnosis.

Mature nymph. 1) Brownish body coloration, without conspicuous marks or patterns (Fig. 2 ), 2) abundant scale-bases throughout most parts of the body (Figs 5b , 6h , 6i , 6k ), 3) Absence of hind wing pads, 4) Tibia with two parallel lines of fine long hairs (Fig. 5b ), 5) posterior margin of tergum III with 28-30 spines on each side of the middle line (Fig. 6h ), 6) sterna with 26-28 variable size spines on each side of the middle line and three thick, spine-like teeth in each corner of the posterior margin of sternum III (Fig. 6i , 6j ), 7) paraproct with about 13-15 spines (Fig. 7k ).

Description.

(based on last instar male and female nymphs; adults unknown).

Size (Mature nymphs): Body length: 5.3-6 mm males, 5.5-6.2 mm females; antennae 1.5-1.7 mm; cerci 2.4-2.7 mm; terminal filament 2.2-2.5 mm.

Body coloration: Brownish in general (Fig. 2A , 2B ), the head light brownish, with clearer area from central ocelli to the border of clypeus and between antennal and labrum bases; ocelli black, with two tiny white symmetrical dots on each side and clear brownish coloration, darker toward ocellus; eyes black, turbinated portion of compound eyes brownish. Fore wing pads brownish, foreleg brown with slightly lighter areas. Abdomen with even brownish coloration on females and males with predominantly brownish color but with segments VII-IX light yellow and light brown, both with no patterns of marks or spots, and upper corners of abdominal segments darkened; terga I-VIII with visible black posterior sigilla in the middle of every segment, terga VII-IX lighter with upper corners darkened; sterna pale yellowish-brown.

Head (Fig. 3A ): Capsule longer than wide. Antennae subequal to 1.3 × length of head, with scape subequal to 1.3 × times length of pedicel (Fig. 3B ). Intra-antennal extension of frons prolongs to ocelli.

Labrum (Fig. 3C ). Subrectangular, broader than long, anterolateral margins rounded; dorsally with anterior margin with about 20 small, double frayed setae. Lateral margin with eight apically frayed setae; arc of anterodorsal setae with four simple setae; intermediate seta tiny; and several small scattered simple setae near posterior margin. Ventrally with small curved fine setae near anterior margin, and seven small simple setae near lateral margin. Anterior margin slightly asymmetric, with the left side of the cleft not extended the same length as the right side (Fig. 3D ).

Left mandible (Fig. 4A ). Incisors with seven denticles, middle one reduced and others similar in size; prostheca robust, apically with three lobes and four elongated projections. Row of 5 or 6 minute spine-like setae between prostheca and molar region, only visible at high magnification (40 ×). Ventral surface of molar region with tuft of spines next to thumb as part of molar structure (Fig. 4B ).

Right mandible (Fig. 4C ). Incisors with seven denticles, middle one reduced and others similar in size; prostheca with broad base, bifid, inner projection longer, and both parts frayed; 3-4 tiny, simple setae between prostheca and molar region only visible at high magnification (40 ×); tuft of spines next to molar region.

Hypopharynx (Fig. 4D ). Lingua rounded with no apical lobes, slightly longer and broader than superlinguae, both apically covered with short fine hairs on dorsal and ventral surface.

Maxillae (Fig. 4E ). Palpi slightly shorter or as long as galea-lacinia, two segmented; segment I slender in mid part; segment II 1.4 × length of segment I; both segments with several simple short setae. Crown of galea-lacinia without thick distal dentisetae, with numerous setae on the inner-dorsal and inner ventral rows, and longer and slender towards the biting edge; medial region of galea-lacinia with one short seta and 5 or 6 long, simple setae.

Labium (Fig. 5A ). Glossa and paraglossa similar in length, basally broad and apically narrow; with the base of the glossa reaching more than half of the paraglossa; glossae dorsally with 7-8 setae next to the inner margin and some scattered setae, ventrally with 12 or 13 setae on the inner margin and 9 or 10 on the outer margin, increasing in length apically in both cases. Paraglossae curve inwards, apex subtriangular, dorsally with 7 or 8 setae on the inner margin and 17 or 18 setae on outer margin. Palpi with segment I broad and 0.8 × length of segment II and III combined, numerous micropores and simple, tiny setae on both dorsal and ventral surfaces; segment II with row of 6 or 7 setae on the dorsal surface; segment III suboval, dorsally with several short simple setae on apex and 20-25 simple setae of different size on the ventral surface, and the inner margin subequal to the outer margin.

Thorax: Hindwing pads absent; foreleg with abundant scale-bases and scattered micropores (Fig. 5B ). Femur length about 4 × maximum with; dorsal edge with 10 or 11 short, simple setae, ventrally bare, apex rounded with no evident projections, and two concave and apically rounded setae. Tibia with two lines of fine hairs arranged parallel to each other along the tibia, subtending bristle elongated and rounded (Fig. 5B, C ). Tarsi dorsal edge bare, ventrally with 10 or 11 minute spines, increasing in size distally; tarsal claw length 0.5 × length of tarsi. Mid and hind legs are similar to the foreleg.

Abdomen: Gills (Fig. 6A-G ). Present on segments I-VII, colorless, oval, margins with curved fine setae (Fig. 6D , 6E ); light-brown tracheae extending from main trunk, branching to margins. Gill I smaller than segment II; gill IV length about 1.3 × length of segment III; gills on segment VII not extending beyond apex of segment X (Fig. 2A, B ).

Terga. Tergum I with no spines on posterior margin; tergum III with 28-30 spines on posterior margin of each side of the middle line, spine bases almost same width as height (Fig. 6J ).

Sterna (Fig. 6I ). Posterior margin of sternum III with group of 26-28 variable size spines on each side of middle line, spines bases width about one-third of height; group of fine hairs arranged in slightly curved line on each side of sterna and three thick spine-like teeth on each corner of posterior margin of sternum III (Fig. 6H ).

Paraprocts (Fig. 6K ). Lateral margin with 13-15 spines, different in size and arranged in irregular line, with some overlapping; dorsal surface with numerous micropores and scale-bases; posterolateral extension with about 11 or 12 marginal spines, and several scale-bases and micropores.

Adults.

Unknown.

Etymology.

The name of this species honors the Danta ( Tapirus bairdii ) ( Mammalia: Tapiridae ), a common species in the Cerro Chompipe cloud forest zone, whose three-toed back feet resemble the sternal spine-like teeth described as a diagnostic character of C. danta sp. nov.

Distribution.

Costa Rican, Caribbean slope basin, first order streams, above 2000 m asl.

Biology.

Habitat preferences in C. danta sp. nov. were observed in relation to elevation. Individuals were found at 2054 m asl in cold waters of two cloud forest streams (Fig. 7 ); other non-Andean species have been reported between 159-1800 m asl ( Nieto and Richard 2008; Gutiérrez and Reinoso-Flórez 2010; Massariol and Salles 2011; Massariol et al. 2013; De Paul et al. 2013; Gutiérrez and Dias 2015). Also, the new species was collected in a pristine forest region, which may be similar to other Cloeodes species in Brazil that seem to prefer remnant forest areas ( Salles et al. 2015). In addition, C. danta sp. nov. is common in riffles, on igneous boulders that are covered with periphyton; this is typical for this genus, part of the grazer functional feeding group ( Baptista et al. 2006).

Figures

Figure 2. Cloeodes danta sp. nov. Body coloration A male B female.

Figure 3. Cloeodes danta sp. nov. A head color pattern and intra-antennal extension detail B scape and pedicel C labrum (left d. v., right v. v.) D detail of labrum asymmetry on anterior margin.

Figure 4. Cloeodes danta sp. nov. A left mandible B detail of molar region, left mandible C right mandible D hypopharynx (left d. v., right v. v.) E maxilla.

Figure 5. Cloeodes danta sp. nov. A labium (left d. v., right v. v.) B foreleg C forefemur apex detail D gill III E gill III apex detail.

Figure 6. Cloeodes danta sp. nov. A gill I B gill II C gill III D gill IV E gill V F gill VI G gill VII H abdominal tergum III I abdominal sternum III J detail of sternum spine-like teeth K paraproct.

Figure 7. Habitat of Cloeodes danta sp. nov. at Rio Las Vueltas.