Miocora aurea (Ris, 1918)

Novelo-Gutiérrez, Rodolfo & Bota-Sierra, Cornelio Andrés, 2022, Description of the final larval stadium of Miocora aurea (Ris, 1918) (Odonata: Polythoridae), Zootaxa 5182 (3), pp. 279-287 : 280-285

Miocora aurea (Ris, 1918)

Figures 1–8

Material. One exuvia (1 ♀, reared), 9 F-0 larvae (6 ♂♂, 3 ♀♀). 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, 3 ♂♂, 3 ♀♀ (1 ♀ emerged on 13 February 2019) ; same data but 2 nd order tributary stream of Río Taibá , 5.2164°N, 76.0883°W, elev. 1600 m, 13 February 2019, C. Bota, R. Novelo, R.W. Sites leg., 3 ♂♂ ; 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., 1 ♀ .

Description. Larva robust ( Fig. 1 ), dorsally yellowish-brown anteriorly, dark brown posteriorly, 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 yellowish-brown with darker areas in a complex color pattern ( Fig. 2a ). Labrum mostly yellowish-brown, sides brown, covered with minute spiniform setae, distally setose, ventrally flat ( Fig. 2b ); clypeus yellowish-brown, with a pair of parallel, white narrow lines along middle third. Frons reddish-brown, vertex yellowish-brown, both flat and granulose, with three large pale ocelli on vertex. Antennae 7-segmented ( Fig. 2a ), longer than head, scape and pedicel brown beset with small scalelike setae, flagellomeres yellowish-brown becoming paler on tip, with minute scale-like setae; size proportion of antennomeres (from basal to apical): 0.70, 1.0, 0.75, 0.50, 0.45, 0.30, 0.20. Compound eyes large, strongly bulging ( Fig. 2a ), with a row of large, dark brown scale-like setae arranged in palisade following the ventral margin of eyes ( Fig. 2b ). Occiput shorter than compound eye dorsal length; cephalic lobes rounded, yellowish-brown dorsally, dark brown posteriorly, beset with 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 ( Fig. 2b ). Mandibles ( Figs. 3a–d ) with molar crest, with following formula: L 1’1 2 3 4 0 a b / R 1’1 2 3 4 y a (m 1–5 or 6) 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. 2b ), subpentagonal, posterior margin concave, anterolateral margins setose. Maxilla: galeolacinia ( Fig. 4 ) with seven teeth, three dorsal teeth moderately incurved ( Fig. 4a ), approximately same size and longest, three ventral teeth of different sizes and shortest ( Fig. 4b ), apical tooth stoutest, a row of 8–10 reddish-brown, stout, long, incurved setae preceding ventral teeth a row of long, white, delicate setae preceding dorsal teeth; maxillary palp shorter than galeolacinia, setose, ending in a robust blunt spine. Labium yellow. Prementum-postmentum articulation reaching anterior margin of mesosternum ( Fig. 1b ). Prementum subpentagonal ( Fig. 5a ), yellow ventrally with a subquadrate gray spot on each side of midline just below of ligula, 0.20x longer than its widest part, lateral margins sinuose and smooth; ligula convex, moderately developed ( Fig. 5b ), 0.18–0.20 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 reddish-yellow, smooth ( Fig. 5b ) 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 yellowish-brown with abundant, minute, scale-like setae, 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 straight, all margins beset with scale-like setae; propleura reddish-brown, 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 mostly yellowishbrown, with basal and costal areas reddish-brown ( Figs. 1a, c ), anterior pair reaching basal half of S7, posterior pair reaching posterior margin of S7, both in individuals with abdomen not relaxed. A blunt, conical, median, dorsal protuberance on posterior margin of metanotum. Legs long ( Fig. 1a ) (i.e., tip of metatibiae surpassing well S10 when fully extended), beset with scale-like setae of different sizes excepting on tarsi; all tibiae longer than respective femora. Femora largely light-brown, laterally compressed; tibiae and tarsi light-yellowish-brown; apicalinternal margin of tibiae with 4–5 thick, robust, reddish, spine-like setae ( Fig. 5c ); tarsi with abundant, stiff setae on ventral surface; pretarsal claws simple, widely separated each other, hooked on apex, with pulvilliform empodium. Thoracic sternum light yellowish-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 brown to dark brown, usually light yellowish-brown on midline of S8–10 ( Fig. 6a ),, beset with small scale-like setae on S3–10 including posterior margins; posterior margin of S10 with a middle, deep, U-shaped emargination. Dorsal protuberances well-developed, caudally-directed, and roundly-tipped on S2–9 ( Fig. 6b ). Lateral margins of S1–8 ventrolaterally expanded, those of S7–8 more developed covered with abundant scale-like setae. Sternum mostly light brown, sterna beset with small scale-like setae. A pair of ventrolateral, grayish-violet, digitiform, tapering, coiled fleshy gills on S2–7 ( Fig. 6c ). Male gonapophyses ( Fig. 6d ) small, with an obtuse tip that reaches the posterior margin of S9, with scale-like setae. Female gonapophyses ( Figs. 7a, b ) well-developed, surpassing by much posterior margin of S10 ( Fig. 7a ); lateral valves densely covered with dark brown scale-like setae on basal 0.80, distal 0.20 smooth, digitiform, and roundly-poited ( Fig. 7a ), central and dorsal valves smooth, 0.21x longer than lateral valves ( Fig. 7b ). Male cerci creamy pale ( Figs. 7c, d ), with dark brown scale-like setae on dorsal surface, in lateral view subquadrate ( Fig. 7d ), dorsal margin slightly convex, ventral margin shallowly concave, distal margin straight, distoventral corner slightly produced ventrally ( Fig. 7d ), in dorsal ( Fig. 7c ) and ventral view appearing digitiform. Female cerci as in male but conical and roundly-pointed in lateral view ( Fig. 8a ). Caudal gills petiolate and inflated ( Figs. 1 , 6a, d , 7d , 8 ), densely covered with scale-like setae, with 4–5 small, conical, roundly-pointed projections ( Figs. 6a , 8 ); central gill (epiproct), in caudal view ( Fig. 8b ), laterally compressed, with five projections ( Fig. 8a ); lateral gills (paraprocts) larger and more inflated than central gill, with four projections, the mesal and ventral surfaces grayish-violet, largely smooth, apparently concave but becoming inflated in alcoholic specimens.

Measurements [averages in brackets]: F-0 larvae: Total length (without caudal lamellae) 10.1–13.7 [12.2; N=9]; maximum width of head 3.1–3.8 [3.62; N=9]; hind femur 3.0–3.4 [3.07; N=9]; abdomen 4.0–6.3 [5.55; N=9]; paraprocts 2.8–3.0 [2.9; N=8]; epiproct 1.8–2.2 [1.98; N=7]. Exuvia: TL 11.5; MWh 3.9; Hf 3.2; Ab 5.0; Pp 2.8.

Diagnosis. The larva of M. aurea is very similar to the larva of M. chirripa , but with the following differences [in square brackets M. chirripa ]: pedicel 0.25x longer than 3 rd antennomere [0.35]; prementum 0.20x longer than its widest part [0.18x]; posterior margin of tergite 10 with a moderate incision [with a deep incision].

Habitat. Larvae of M. aurea inhabit small shallow forested streams, crawling among sand, gravel, small stones where the water flow is moderate.

Figures

FIGURE 1. Miocora aurea, habitus dorsal (a), ventral (b), and lateral (c) of F-0 male larva.

FIGURE 2. Miocora aurea, details of larval morphology. a) Head, dorsal view; b) head, ventral view (labium detached).

FIGURE 3. Miocora aurea, details of larval morphology. a) Right mandible, mesal view; b) same, mesoventral view; c) left mandible, mesal view; d) same, ventral view.

FIGURE 4. Miocora aurea, details of larval morphology. a) Right maxilla, dorsal view; b) same, ventral view.

FIGURE 5. Miocora aurea, details of larval morphology. a) Prementum, ventral view; b) ligula and palps, dorsal view; c) distal half of right metatibiae and tarsi, ventral view.

FIGURE 6. Miocora aurea, details of larval morphology. a) S8–10 and caudal gills, dorsal view; b) abdomen profile, female left lateral view; c) abdomen of female, ventral view, showing the lateroventral, coiled, digitiform gills; d) sterna 8–10, male gonapophyses, and caudal gills, ventral view (notice the areas lacking scale-like setae on paraprocts). c) male gonapophyses, lateral view; d) female gonapophyses, lateral view.

FIGURE 7. Miocora aurea, details of larval morphology. a) S8–10 and female gonapophyses, lateral view; b) same, ventral view; c) S9–10 and male cerci, dorsal view (caudal gills detached); d) S8–10 and caudal gills showing male cerci, and the large, violaceous, mesal area of right paraproct devoid of scale-like setae, left lateral view (left gill detached).

FIGURE 8. Miocora aurea, details of larval morphology. a) Left female cercus (Ce) and caudal lamellae, laterodorsal view. b) epiproct, caudal view.