Archilestes exoletus

Dalzochio, Marina Schmidt & Rodrigues, Marciel Elio, 2011, Description of the larva of Archilestes exoletus (Hagen in Selys) (Odonata: Lestidae), Zootaxa 2756, pp. 65-68 : 66-67

Archilestes exoletus (Hagen in Selys, 1862)

Figures 2 – 8

Diagnosis. Lateral margin of S4 without lateral spine, articulation of prementum with postmentum at metacoxa level, cercus sharp, cleft of the ligula closed, female gonapophyses reaching ½ length of S10 and posterior margin of male gonapophysis concave.

Larva. Body elongated, especially abdomen; general color ochraceous, antennal base smudged, frons and occiput with dotted macules; ocellus well marked, surrounded by black; legs with dotted macules at femora articulation with tibiae and also tarsi; tergites darkened laterally over the midline of S4 – 8, especially at the apex of each segment ( Fig. 2 ).

Head. Trapezoidal in shape, flattened dorso-ventrally, about 2 times as wide as long, with posterior margin distinctly convex, cephalic lobes rounded with small spines on the posterior margin. Antenna 7-segmented, pale in color, first antennomere most robust, third antennomere longest ( Fig. 3 ). Labium elongate, hardly constricted at basal half, longer than wide, prementum-postmentum articulation reaching base of third coxa. Prementum with five setae on each side, lateral margin with eight spine-shaped setae, palp-articulation with two setae of same size and shape, distal margin (ligula) slightly crenulated and with an auriculated elevation prior to palp-articulation on each side. Labial palp with three setae, two located on movable hook. Articulation with movable hook bearing three spine-shaped setae. Palp with three deep and sharp crenulations, lower margin of first crenulation with a series of discrete denticles ( Fig. 4 ).

Thorax. Prothorax small, with lateral angles of distal margin pronounced and rounded on each side. Synthorax quadrangular. Hind wing pads extending to anterior margin of S4. Legs long with hind pair exceeding S10 when fully extended ( Fig. 2 ).

Abdomen. Elongate, cylindrical, lateral carinae well-developed on S4 – 10. Small lateral spines on S5 – 9 ( Fig. 2 ). S9 of male with pyramidal gonapophyses, lower margin serrated, apex pointed, anterior and posterior margins concave ( Fig. 5 ). Female gonapophyses long, reaching level of S10, curved in basal 3/4 and with a row of marginal spines, sharp and straight in apical ¼ ( Fig. 6 ), apex of ovipositor oval, reaching base of caudal lamellae ( Fig. 6 ). Abdominal segments covered with setae, including a row of small spines on distal margin. Cerci straight, curved in proximal ¾, apex sharp ( Fig. 7 ). Caudal lamellae foliate, apex rounded, parallel secondary tracheae radiating from thick main trachea; no transverse suture; lateral and dorsal carinae flat; lamella widest proximally ( Fig. 8 ).

Measurements. Overall length (excluding caudal lamellae): 52.50 – 60.00; head length: 2.00 – 2.25; maximum head width: 4.00 – 4.50; antennomere length: I, 0.55 – 0.63; II, 0.78 – 0.88; III, 1.88 – 1.93; IV, 1.25 – 1.28; V, 0.75 – 0.88; VI, 0.50 – 0.50; VII, 0.13 – 0.25; labium length: 6.00 – 6.50; maximum labium width: 2.00 – 2.47; cercus length: 1.45 – 1.55; median caudal lamellae length: 10.20 – 10.80; maximum median caudal lamellae width: 2.10 – 2.50.

Material examined. BRAZIL: PARANA state: Cascavel, Danilo Galafassi Municipal Park, source of the Rio Cascavel (24º56’57,93594”S – 53º25”57,35321”W): one male exuvia (last instar larva collected 05.v.2006, emerged 16.v.2006) and one female exuvia (last instar larva collected 19.v.2006, emerged 29.v.2006), G.S. Andrade; M.E. Rodrigues & M.S. Dalzochio leg.

Figures

FIGURES 2 – 8. Archilestes exoletus: (2) Final instar exuvia. (3) head, dorsal view. (4) labium, ental view. (5) male gonapophysis, lateral view. (6) ovipositor, lateral view. (7) Abdominal segment 10, lateral view. (8) lateral and median caudal lamella, lateral view.