Enderleina preclara (Derka & Tierno de Figueroa, 2013)

Derka, Tomáš, Figueroa, J. Manuel Tierno De & Čiampor, Fedor, 2019, Enderleina preclara Jewett, 1960 (Plecoptera, Perlidae), from the Venezuelan Guayana-A description of a putative female, nymph and egg, Zootaxa 4585 (2), pp. 332-342 : 335-339

Enderleina preclara putative female, nymph and egg

Figs. 7 –22

Female description. ( Figs. 7–15 ): Total length: 12 mm, Forewing: 17 mm. General color (in dorsal view) brown, except for a mostly dark brown head and orange pronotum ( Fig. 7 ), the specimen from Kukenán-tepui is generally darker than the specimens from Acopán-tepui; in lateral and ventral views brown, except for dark brown areas on the head, meso- and metathorax and whitish prothorax ( Figs. 8–10 ). Head ( Fig. 7 ) dark brown from the parietal region to frons, except for whitish anterolateral margins; antennae brown, light brown or whitish in the proximal part; eyes black, three ocelli brown, anterior ocellus ca. 1/3 the diameter of lateral ocelli; head ventral region light brown to whitish, except for a dark brown submentum ( Fig. 8 ). Pronotum ( Fig. 7 ) orange, rectangular, anterior margin convex, corners rounded, prothorax ventrally whitish with a triangular yellowish central area; meso- and metathorax ventrally brown with a dark brown central area ( Figs. 8, 10 ); wings infuscate with brown; legs ( Figs. 13–15 ) brown, except for a dark brown posterior margin of the trochanter, a distal part of the femur and proximal anterior part of the tibia; femur and tibia with narrow paler bald strips. Abdomen and cerci brown, in some individuals with darker spots ( Fig. 9 ), subgenital plate ( Figs. 11–12 ) trapezoidal, longer than the sclerotized band S9, as wide in its distal part as the S9 (see also Fig. 9 for lateral view), a notch on the posterior margin U-shaped (in some cases can resemble V-shaped), longer setae on the distal half; cerci dark brown, with abundant setae.

Nymph description. Body length (not including cerci) 10 mm. Body yellowish-brown with some darker areas (Fig. 18). Head (Fig. 19) yellowish-brown with a dark brown triangular band from the parietal region to frons; antennae proximally brown, distally lighter; eyes black, ocelli paler, lateral ocelli larger than anterior ocellus; mouth parts yellowish, except for a brown submentum (Fig. 20). Pronotum (Fig. 19) yellow, in last instars with a visible orange adult pronotum, a yellowish meso- and metanotum (Fig. 18) with U-shaped dark spots; wingpads dark brown, thoracic segments ventrally (Fig. 20) yellowish with darker brown central areas; legs (Figs. 18, 20–22) yellowish, except for a dark brown the posterior margin of the trochanter, a distal part of the femur and proximal anterior part of the tibia; tibiae darker than femurs. Abdominal tergites (Fig. 18) yellowish-brown, lateral parts darker, sternites (Fig. 20) yellowish, last segments darker; cerci dark brown. Gill formulae and other characters agreeing with Stark (1989) diagnosis for Enderleina .

Egg description. Eggs are on average 458 µm long (range = 420–480 µm; SD = 14 µm; N = 16), and 300 µm wide (range = 280–320 µm; SD = 10 µm; N = 16). The egg is light yellow, elongate, oval shaped, rounded in the apexes, slightly narrowed at one end ( Fig. 16 ), circular in cross-section. Chorion covered by a coating, smooth, in some areas where this coat was removed, aeropyles could be observed. Aeropyles ( Fig. 17 ) are on average 348 nm diameter (range = 287 – 412 nm; SD = 51 nm; N = 8). Micropyles not observed. The hexagonal chorionic follicle impressions ( Fig. 17 ) not obvious (radius average 19.64 µm, range = 15.69 – 24.34; SD = 3.91 µm; N = 4). The attachment disc not observed, only in some eggs a small button-like structure seemed to be present in the apex of the wider pole. The egg mass covered by a smooth coat, to which each egg was attached by the wider apex.

Ecological notes. The flying adults were collected during the day. The sampling sites were 5–8 m wide montane streams with stony and boulder substrate (Figs. 4–6). Water temperature ranged from 16.2 to 19.1 °C. All streams were bordered by riparian forests. The locality below Kukenán-tepui is situated in a secondary savanna, which replaced the original mountain forest, Acopán-tepui localities are surrounded by undisturbed native montane forests and swamps.

Figures

FIGURES 7–10. A putative female of E. preclara. 7, head and thorax, d. v.; 8, head and thorax, v. v.; 9, a general view, laterally; 10, a general view, ventrally.

FIGURES 11–17. 11–15, a putative female of E. preclara. 11–12, subgenital plate; 11, a female from Acopán-tepui, 12, a female from Kukenán-tepui; 13–15, legs; 13, foreleg; 14 middle leg; 15, hind leg. 16–17, egg photographs; 16, a photograph from a binocular microscope; 17, egg chorion detail from a scanning microscope.