Chilenoperla puerilis

Pessacq, Pablo, 2016, Redescription of Chilenoperla puerilis (Gripopterygidae: Plecoptera) from the eastern Andes of Patagonia, Zootaxa 4109 (1), pp. 89-95 : 90-93

Chilenoperla puerilis

Figs. 1–4

Chilenoperla puerilis, Illies, 1963: 226 -227, figs. 39 and 42 (Male description based on a pharate male, larval description (under the name C. brundini ; lapsus), type locality: Laguna Margarita, Peulla, Province Llanquihue, Chile). Miserendino & Pizzolon 2000, altitudinal zonation in Patagonian macroinvertebrates; Miserendino 2001, macoinvertebrate assemblage in Patagonian streams; Velázques & Miserendino 2003, macroinvertebrate functional groups in Patagonia.

Chilenoperla semitincta, Pessacq & Miserendino 2008 , first species record for Argentina (specimen from Yrigoyen stream, National Park “Los Alerces”); Pessacq 2009, species list.

Material studied. Two male adults, ARGENTINA, Chubut Province, Esquel Stream, 12 km from Esquel, road access to “La Hoya’’ ski resort, 42°50’28’’ 71°15’55’’, 6/XI/2012, P. Pessacq leg. One male, same as previous except for: 1/XI/2007. One male same as previous except for: reared in laboratory, emerged 28/XI/2012. One female, same as previous except for: reared in laboratory, emerged 7/XI/2012. Four final instar larvae and four F‒1 instar larvae, same as previous, except died during rearing, 14/XI ‒ 17/X /2012. One male, National Park “Los Alerces”, Yrigoyen Stream at junction with National Route 71, 42°30’57’’ 71°21’43’’, 11/XI/2009, P. Pessacq leg.

Diagnosis. Adult: Slender, brown, medium size gripopterygid. Posterior sclerite clearly demarcate from central sclerite, subapical, with a short spiniform process directed ventrally; epiproct well developed, with two lateral rows of teeth. Wing with RA-RP fork short, without transverse veins; CuA in hind wing short, without transverse veins. Larva: Slender, brown, medium sized Plecoptera , margins of pro-, meso-, metanotum and abdominal segment margins with a dense row of short, thick, spine-like setae.

Adult redescription. Head. Brown, labrum and clypeus light brown, frons brown with two lateral black spots on its middle line and two smaller spots posterior to these. Two black lateral spots in front of the posterior ocelli. Ventral surface of head light yellow, except for darker palps and sclerotized mandible. Maxillae with a fivesegmented palp, fifth and third palpomeres about equal and the longest, followed in length by the fourth and second, first the shortest. Antenna 5 times longer than head width, covered with hair-like setae, scape about two times as long and wide as pedicel; flagellum, with 44–46 annuli. Thorax. Dark brown, almost black. Pronotum 1.5 as wide as long, covered with small hair‒like setae, more dense and long in the anterior side, margins straight, lateral margins slightly convergent anteriorly, corners rounded. Legs brown, long and slender, covered with small hair‒like setae and long needle‒like setae in extensor margin, femur II and III basally yellow, tibiae with a wide yellow medial band. Wings ( Fig. 2 ) light brown, transverse veins complete, but some small light areas close to main venation in fore wing may suggest a very few incomplete veins. RA-RP fork short, without transverse veins, CuA short, without transverse veins. Abdomen. Brown. sternites II‒ VIII rectangular. Tergum X ( Fig. 1 ) with an anterior triangular membrane. Anterior sclerite greatly narrowed medio‒dorsally, forming two plates that meet in one point ( Fig. 1 material from La Hoya Stream) or in a narrow band ( Fig. 2 a, material from Yrigoyen stream) without dorso-lateral tubercles. Lateral and central sclerites fused, anterior margin slightly convex, in dorsal view wide basally and gently tapering to apex in basal half, strongly tapering to apex in apical half, apex rounded. Posterior sclerite small but clearly demarcated from central sclerite, subapical in the ventral margin of central sclerite, visible in dorsal view, well sclerotized, with a short spiniform process directed ventrally. Epiproct well developed, with two lateral rows of four slightly variably sized teeth ( Figs. 1 a, 2b). Paraprocts ( Fig. 1 a) well developed, curved upwards and surpassing segment X distal margin, apex rounded. Cerci composed of seven segments, covered with curved hair-like setae.

Measurements (in mm, n=5): total body length 8.75± 0.8, head max. width 1.68 ± 0.1, antennae 8.24 ± 0.57, maximum pronotal width 1.47 ± 0.02, maximum pronotal length 1.47 ± 0.02, fore wing 10.125 ± 0.43, cerci 0.52 ± 0.08.

Last instar larva description. The habitus is as illustrated by Illies (1963). Head. Brown, densely covered by short spine-like setae. Eyes small, three small ocelli. Cephalic suture poorly visible. Antenna about as long as 3.8 times maximum head width, densely covered with hair-like setae; flagellum with 60–70 annuli. Mandibles as in Fig. 4 . Maxilla ( Fig. 4 f) with palp proportions approximately 1:2:4:3:4. Galea and lacinia as in Fig. 4 f. Labium ( Fig. 4 e) longer than wide, with a three-segmented palp covered with short hair-like setae, distal palpomere longest, basal one shortest. Thorax. brown; covered with hair-like setae, all margins, including wing pads with a dense row of short, thick spine-like setae ( Figs. 3 a–b). Pronotum ( Fig. 3 a) dark brown, rectangular, angles rounded, about 1.6 times as wide as long, lateral margins straight or slightly convex, anterior margin slightly concave, elevated on its middle section, posterior margin convex. Mesothoracic wingpads slightly divergent; metathoracic wingpads strongly divergent ( Fig. 3 b). Legs brown, tibiae with a wide middle yellow band; legs covered with thin short hair-like setae and sparse, straight and long needlelike setae on extensor margin. Tarsi brown, proportions of segments about 2:1:3. Abdomen. Brown, its dorsal surface covered with hair-like setae, more dense in the surface of segment X. Margin of all segments with a dense row of short spine-like setae. Tergites and sternites of segments I and II divided by a membranous area, those of segment III incompletely divided, remaining segments forming a complete ring; segment X large, with posterior margin rounded. Cercus composed of 20–25 annuli, each of them progressively thinner and longer to apex. Anal gill with many filaments.

Distribution. Valdivian Forest Province (Andean region, Subantarctic subregion, Chile, type locality: Laguna Margarita, Peulla, Province Llanquihue, Chile). Subandean Patagonia province (Andean region, Patagonian subregion, Chubut Province, Argentina) in the ecotone between Nothofagus forest and Patagonian steppe (La Hoya Stream) and in the Nothofagus forest (Yrigoyen Stream).

Figures

FIGURE 1. Genitalia of Chilenoperla puerilis. Adult male (La Hoya Stream). 1 a, genitalia, lateral view. 1 b, genitalia, dorsal view.

FIGURE 2. Tergum X and epiproct of Chilenoperla puerilis. Adult male (Yrigoyen Stream). 2 a, tergum X, dorsal view. 2 b, epiproct lateral view.

FIGURE 3. Larva of Chilenoperla puerilis. Last instar larva (Esquel Stream). 3 a, pronotum, dorsal view. 3 b, meso and metanotum, dorsal view. 3 c, d, mandibles in ventral view. 3 e, labium, dorsal view. 3 f, right maxilla, dorsal view.

FIGURE 4. Wings of Chilenoperla puerilis. Adult male (Yrigoyen Stream). 2 a, fore wing. 2 b, hind wing.