Cora inca Selys, 1873

Novelo-Gutiérrez, Rodolfo & Bota-Sierra, Cornelio Andrés, 2023, The larvae of Cora inca Selys, 1873 and Polythore gigantea (Selys, 1853) from Colombia (Odonata: Polythoridae), with a larval diagnoses of some genera in the family, Zootaxa 5254 (4), pp. 517-533 : 518-524

Cora inca Selys, 1873

Figures 1–5

Material. Three exuvia (3 ♀♀, reared), 6 F-0 larvae (2 ♁♁, 4 ♀♀). COLOMBIA: Risaralda Department, Tatamá National Park, Pueblo Rico Municipality , Monte Bello Township , Montenegro stream, 5.2273°N, 76.0830°W, elev. 1363 m, 12 February 2019, C. Bota, R. Novelo, R.W. Sites leg, 2 ♁♁, 5 ♀♀ (3 ♀♀ emerged on 16–19 February 2019) ; same data but Minas de Cristal de Cuarzo stream, 5.2286°N, 76.0981°W, elev. 1480, 14 February 2019, C. Bota, R. Novelo leg., 2 ♀♀ .

Description

Larva robust ( Fig. 1 ), dorsally dark brown, ventrally yellow anteriorly, grayish-violet posteriorly. Abdomen strongly convex dorsally, flat ventrally; digitiform, coiled, ventrolateral gills on S2–7; caudal gills petiolate, inflated, and scaly.

Head: Wider than long, posterior margin widely concave, dorsal color mostly yellowish-brown with darker areas in a complex color pattern ( Fig. 2a ). Labrum dark brown with a large, central, oval yellowish-brown spot, covered with minute scale-like setae, distally setose, ventrally flat; clypeus yellowish-brown. Frons yellowish-brown with four yellow spots ( Fig. 2a ); vertex dark brown, both flat and granulose, with three large pale ocelli on vertex. Antennae 7-segmented ( Fig. 2b ), shorter than head, scape and pedicel brown, thicker, beset with small scale-like setae, first flagellomere brown, remaining flagellomeres yellowish-brown becoming paler on tip, with minute scalelike setae; size proportion of antennomeres (from basal to apical): 0.75, 1.0, 0.60, 0.45, 0.30, 0.25, 0.10. Compound eyes large, strongly bulging ( Fig. 2a ), with a row of large, dark brown scale-like setae arranged in palisade following the antero-ventral margin of eyes. Occiput shorter than compound eye dorsal length ( Fig. 2a ), granulose, dark brown dorsally with a rectangular, bare, yellow spot to each side of midline; cephalic lobes rounded, mostly bare and yellow posteriorly, beset with longitudinal rows of small scale-like setae ( Fig. 2a ); subocular areas of head yellow, with a well-developed, longitudinal carina which extends to posterior margin of cephalic lobes. Mandibles ( Figs. 2 c-f) with molar crest, with following formula: R 1’1 2 3 4 0 a b / L 1’1 2 3 4 y a (m 1–6 or 7) b, both mandibles fringed with a ventral and dorsal, transverse, row of long, stiff setae; basal-external surface shallowly concave. Ventral pad of hypopharynx creamy-pale ( Fig. 3a ), subpentagonal, posterior margin concave, anterolateral margins setose, with an irregular patch of minute, gray scales to each side of the ventral midline ( Fig. 3a ). Maxilla: galeolacinia ( Fig. 3b ) with seven teeth, three dorsal teeth moderately incurved, approximately same size and longest, three ventral teeth of different sizes and shortest, apical tooth stoutest, a row of stout, long, incurved setae preceding ventral teeth ( Fig. 3b ), a row of long delicate setae preceding dorsal teeth; maxillary palp shorter than galeolacinia, setose, ending in a robust blunt spine. Labium yellow. Prementum-postmentum articulation reaching posterior margin of prosternum ( Fig. 1b ). Prementum subpentagonal ( Fig. 3c ), yellow to yellowish-brown ventrally, 0.20x longer than its widest part, lateral margins sinuose and smooth; ligula convex, moderately developed ( Fig. 3d ), 0.20 as long as its basal width measured dorsally, distal margin serrulate with a small, narrow, v-shaped, median cleft, a small, submarginal tooth on each side of median cleft but rather far from it. Premental palp yellowish-brown, smooth ( Fig. 3d ) with three end hooks shorter than movable hook, the ventral (mesal) one shortest and truncated, internal margin of palp finely serrate; movable hook reddish, smooth, incurved, sharply-pointed, shorter than palpal lobe.

Thorax: Pronotal disk subtrapezoid ( Fig. 1a ), mostly brown with abundant, minute, scale-like setae except on a boomerang-shaped, bare area to each side of midline, anterior lobe large and subtriangular, anterior margin straight, lateral margins concave at middle, slightly reflexed and rimmed, anterolateral corners produced as a blunt, triangular process, posterior margin slightly convex, all margins beset with scale-like setae; propleura reddishbrown, propleural apophyses short and roundly-pointed, beset with scale-like setae, proepimeral apophysis largest. Pterothorax mostly dark brown ( Figs. 1a, c ), covered with minute scale-like setae, ventral margin of mesothorax straight, that of metathorax sinuose. Wing sheaths divergent, mostly brown ( Figs. 1a, c ), anterior and posterior wing sheaths reaching basal margin and posterior margin of S9, respectively, in individuals with abdomen not relaxed. A hump-like protuberance on metanotum. Legs long ( Fig. 1a ) (i.e., tip of metatibiae reaching basal half of paraprocts when fully extended), beset with scale-like setae of different sizes excepting on tarsi; all tibiae longer than respective femora. Femora largely brown, laterally compressed, with three longitudinal carinae, one dorsal and two ventral, all beset with rows of scale-like setae; tibiae dark brown, tarsi light-yellowish-brown; apical-internal margin of tibiae with 4–5 thick, robust, reddish, spine-like setae; tarsi with abundant, stiff setae on ventral surface; pretarsal claws simple, widely separated from each other, hooked at apex, with pulvilliform empodium. Thoracic sternum light grayish-brown, beset with dark scale-like setae; metasternum divided into four sternites, with laterosternites produced medially as large ovoid plates ( Fig. 1b ).

Abdomen: Subcylindrical, strongly convex dorsally, flat ventrally, wider at base, narrowing caudally ( Fig. 1 ). Tergites dark brown ( Fig. 4a ), beset with small scale-like setae on S3–10 including posterior margins; posterior margin of S10 with a middle, deep, V-shaped emargination ( Fig. 4b ). Dorsal protuberances well-developed, caudally-directed, and roundly-tipped on S2–9 ( Fig. 4a ), smaller on S1, all of them covered with scale-like setae. Lateral margins of S1–8 ventrolaterally expanded, those of S7–8 more developed covered with abundant scalelike setae ( Fig. 1a ). Sternum mostly light brown to grayish-brown, sterna beset with small scale-like setae. A pair of ventrolateral, grayish-violet, digitiform, tapering, coiled fleshy gills on S2–7 ( Fig. 1b ), with approximately their basal half covered with scale-like setae ( Fig. 4c ). Male gonapophyses ( Fig. 5a ) small, with an obtuse tip that scarcely surpasses the posterior margin of S9, with a row of small, dark, reddish-brown, conical spines along their full ventral midline; gonopore’s area as a large, circular, creamy pale spot. Female gonapophyses ( Fig. 5b ) welldeveloped, surpassing posterior margin of S10; lateral valves densely covered with dark brown scale-like setae along basal 0.80, their ventral margins strongly convex, with a row of small, dark, reddish-brown, blunt spines, distal 0.20 smooth, digitiform, and roundly-pointed ( Fig. 5b ), central and dorsal valves smooth, 0.10x longer than lateral valves ( Fig. 5b ). Male cerci light yellowish-brown ( Figs. 4a–b , 5a ), with dark brown scale-like setae on dorsal and lateral surfaces, ventrally smooth, roundly pointed. Female cerci as in male but conical and roundlypointed ( Fig. 5b ). Caudal gills petiolate and inflated, dark brown ( Figs. 1 , 5c–f ), densely covered with scale-like setae, with 5–6 large, conical projections ( Figs. 5c–f ); central gill (epiproct) with one ventrobasal, three apical, and two laterodorsal projections ( Fig. 5e ); lateral gills (paraprocts) larger, with two apical and two dorsal projections, and one laterodorsal projection, a ventroapical brush of white, short, stiff setae ( Fig. 5f ).

Measurements [averages in brackets]: F-0 larvae: Total length (without caudal lamellae) 11.0–16.8 [14.3; N=5]; maximum width of head 4.4–4.7 [4.5; N=6]; hind femur 4.2–4.7 [4.4; N=6]; abdomen 4.5–8.8 [6.8; N=5]; paraprocts 5.0–5.8 [5.3; N=3]; epiproct 3.8–4.2 [4.0; N=3]. Exuviae: TL 14.0–15.7 [15.0; N=3]; MWh 4.5–4.8 [4.67; N=3]; Hf 4.5–4.7 [4.6; N=3]; Ab 6.0–7.4 [6.9; N=3]; Pp 5.5–5.7 [5.5; N=3]; Ep 4.0.

Diagnosis

The larva of C. inca is very similar to the larvae of C. cyane and C. marina ; the main differences separating them are found in the caudal gills. Unfortunately, we had no specimens of C. cyane available to make a more precise comparison, so some features of this species were taken from De Marmels (1982, 2007). Differences are as follows [characters for C. cyane and C. marina in square brackets]: an irregular patch of minute, gray scales to each side of the ventral midline on the ventral pad of hypopharynx ( Fig. 3a ) [absent in C. marina , unknown in C. cyane ]; dorsal protuberance on S8 slender, with dorsal margin straight ( Fig. 4a ) [robust, dorsal margin convex in C. marina ( Fig. 6a ), low with margin convex ( De Marmels 2007: fig. 23)]; paraprocts with five projections [six in C. cyane ( De Marmels 1982) , 5–6 in C. marina ]. For practical purposes, we have numbered the caudal gills projections according to figures 5e–f and 6b–c: Epiproct: projection 1 well-developed, at basal 0.15 ( Fig. 5e ) [very reduced, at basal 0.45 in C. marina ( Fig. 6b ), apparently well-developed, at 0.35 in C. cyane , according to De Marmels (1982: fig. 2)] (epiproct’s full length measured from the peduncule’s insertion to the tip of projection 4); distance between tips of projections 2 and 3 0.5 longer than the length of projection 3 ( Fig. 5e ) [0.3 in C. marina ( Fig. 6b )]; projections number 5 and 6 at midlength ( Fig. 5e , projection 6 not visible in this figure) [at basal 0.60 in C. marina ( Fig. 6b )]. Paraproct: projections 1–3 at 0.10, 0.55, and 0.90 the length of paraproct, respectively ( Fig. 5f ) [at 0.35, 0.55, and 0.75, respectively in C. marina ( Fig. 6c )]; projections 2–3 short, spine-like ( Fig. 5f ) [short and blunt in C. cyane according to De Marmels (2007: fig. 25), long and slender in C. marina ( Fig. 6c )]; projection 5 at basal 0.45 ( Fig. 5f ) [at 0.50 in C. marina ( Fig. 6c )].

Habitat

Larvae of C. inca inhabit small shallow forested streams, crawling among sand, gravel, or small stones where the water flow is moderate.

Figures

FIG. 1. Cora inca, dorsal (a), ventral (b), and lateral (c) habitus of F-0 female larva.

FIG. 2. Cora inca, details of larval morphology, a) head, dorsal view; b) left antenna, lateral view; c) right mandible, mesal view; d) same, ventromesal view; e) left mandible, mesal view; f) same, ventromesal view.

FIG. 3. Cora inca, details of larval morphology, a) hypopharynx, ventral view (arrows indicate patchs of scales); b) left maxilla, ventral view; c) prementum, ventral view; d) ligula and palps, dorsal view.

FIG. 4. Cora inca, details of larval morphology, a) Abdomen profile, male left lateral view; b) S8–10 and male cerci, dorsal view; c) detail of two lateroventral gills showing basal half covered with scale-like setae and distal portion coiled, lateral view.

FIG. 5. Cora inca, details of larval morphology, a) sternites 8–10 showing male gonapophyses and cerci (caudal gills detached); b) female gonapophyses and cerci, ventral view; c) S8–10 and caudal gills, dorsal view; d) same, lateral view; e) epiproct, left lateral view, showing projections 1–5 (projection 6 not visible, it is in the opposite side of projection 5); f) left paraproct, lateral view, showing projections 1–5.

FIG. 6. Cora marina, details of larval morphology, a) abdomen profile showing dorsal protuberances, left lateral view; b) epiproct, left lateral view, showing projections 1–5 (projection 6 not visible, it is in the opposite side of projection 5); c) left paraproct, lateral view, showing projections 1–5.