Archilestes chocoanus, Pérez Gutiérrez, 2012

Pérez Gutiérrez, L. A, 2012, Archilestes chocoanus, a new damselfly from Colombia (Odonata: Lestidae), Odonatologica 41 (4), pp. 347-352 : 348-351

ARHILESTES CHOCOANUS SP. NOV.

Figures 1-3

Material. − Holotype ♂, COLOMBIA, Chocó Department, Salero (05°19¢ 01² N, 76°36¢ 52² W) alt. 129 m, 10-VIII-2005.L.A. Pérez leg.( UARC). − Paratype ♂, same data ( MIZA).− Allotype ♀, same data ( UARC) . − Other species examined: A. regalis ♂, Tamazunchale, San Luís Potosí, Mexico 30- VIII-1958, Beatty leg. & Beatty det., 1959. JR- 08291. − A. californicus ♂, ♀ (in tandem) Calif: Stanislaus co., Del Puerto Cyn. at N. Fork of Del Puerto Creek about 14 mi. W. of Patterson, 21/ 23- IX- 1978, R.W. Garrison leg. & det., 1978. − A. tuberalatus ♂, Choroní, La Rinconada, 350 m, AR, 18-XII-2003, J. De Marmels leg. & det. − A. grandis ♂, Rancho Grande, Aragua, Venezuela, 500 m, 16-IX-1951, Y. Fernandez leg., J. Racenis det., 1954. − A. guayaraca ♂ (holotype) Guayaraca, Auyantepuí, Bolivar, Venezuela, 25-IV-1956.

Etymology. − The species name is dedicated to the amazing but endangered exuberant Chocoan Pluvial Forest.

MALE (holotype). − H e a d ( Fig. 1a ). − Labium yellow, base of mandible pale green, tip black; labrum pale green, margin rimmed with a thin black line; anteclypeus pale green, postclypeus entirely shiny black. Gena ochre; frons, vertex and top of head dark metallic green, antenna with scape and pedicel black, flagellum brown. A small, pale spot externally at each lateral ocellus. Rear of head yellow, black near maxillar insertion.

Thorax. − Anterior lobe of prothorax rounded, black ( Fig. 1b ), middle lobe metallic green with longitudinal mid line and lateral region yellow, posterior lobe dark metallic green with small central yellow spot; proepisternum and proepimeron yellow with pruinescense ( Fig. 1c ); procoxa largely yellow with pruinescence. Pterothorax largely yellow laterally with broad green metallic stripes bordered black. Mesepisternum in dorsal view largely metallic green, middorsal carina yellow, in lateral view green metallic with thin yellow stripe along humeral suture ( Fig. 1d ). Mesokatepisternum largely black with metallic green luster, inferior portion yellow. Mesepimeron entirely metallic green with a narrow, shiny black stripe along interpleural suture. Mesocoxae yellow with external black stripe ( Fig. 1d ). Metepisternum largely yellow with inferior margin along pleural suture with shiny black stripe extending to superior margin of metepimeron. Distal half of paracoxal suture with shiny black stripe. Metepimeron and metasternum largely yellow with thin, black longitudinal line in middle, and with a lateral black spot. Metakatepimeron yellow and pruinose. Meso- and metascutum yellow, meso- and metaescutellum yellow.

Legs ( Fig. 2a ). − Mainly dark brown to black. Trochanter with ventral surface yellow, and posterior side black; femur in proximal quarter with pale inner side, meso and metafemur with 8-10 spines of approximately the same size on its outer surface. Wings ( Fig. 2b ). − Hyaline, veins black, pterostigma dark reddish brown, proximal side of quadrangle 0.87 mm (same in allotype and paratype); posterior side 1.87 mm (1.62 in allotype and 1.75 in paratype) and anterior side 0.75 mm (in paratype and allotype 0.62). Petiolation reaching level of arculus. First antenodal space 4.87mm (4.75 in paratype and same in allotype), third antenodal space 5.87 mm (5.62 in allotype and 5.37 in paratype). Broadening ratio 1.05 (1.1 in paratype, 1.05 in allotype). Radial side of pterostigma 2.5 mm (same in allotype and paratype). The elongation ratio of the first post-quadrangular cell, defined as the relative lengths of the anterior to the distal vein of that cell (sensu DONNELLY, 1981; GARRISON, 1982) ranges from 2.0 to 2.33 (1.79-2.0 in paratype). − Fw: Pt surmounting almost 4 crossveins; two complete Ax, 21 Px. RP 2 arising from RP 1 between Px 3 and 4. − Hw: Pt surmounting 4 crossveins, two complete Ax; 17 Px. RP 2 arising in RP 1 in 3 Px.

Abdomen. − Abdominal segments largely green, lateral sides of S1 and S2 partially yellow with dark spots ( Fig. 1d ), lateral side of S3 with a yellow oval spot close to posterior distal transverse carina, terga with a thin yellow line along the ventral margin, widest in S8; ventral pruinecense on S8-10, S10 black. Posterior hamule brown, lobulated and concave ( Fig. 2c ). Apical segment of genital ligula oval. ( Fig. 2 d-f).

Cercus entirely black, slightly directed upwards ( Fig. 3a ) and pointed with acute basal tooth mesally in the first third of its length ( Fig. 3b ), middle region of cercus concave, followed by a post-median expansion armed with 7-8 strong spines on internal margin and dorsally with a prominent tubercle excavated, paraproct vestigial ( Fig. 3c ), in lateral view extending scarcely beyond at base of cercus, approximately 24 % of cercus length; tips of cerci in natural position crossed.

Measurements (in mm). − Fw 38.3, Hw 36.7, abdomen (excluding appendages) 51.5, cercus 2.1 (61% longer than S10), paraproct 0.5.

FEMALE allotype ( Fig. 3d ). − Appearance and size as in male, ovipositor with a distintive color pattern, lateral valves armed with 12-14 small spines on ventral margin, all approximately the same size.

Measurements (in mm). − Abdomen without appendages 42.0, cercus 1.06, paraprocts 0.87.Elongation ratio of the first post-quadrangular cell 2.0-2.1. VARIATION. − Male paratype as holotype, but RP2 vein arising in 3 Px, in 4 Px and 3 Px in left and right Hw respectively.

DIAGNOSIS. − Morphologically the new species is closely related to A. guayaraca DE MARMELS, 1982, A. latialatus DONNELLY, 1981 and A. tuberalatus ( WILLIAMSON, 1921). With this latter it shares the presence of an robust basal tooth (specimens examined from Choroní, Aragua), although in A. tuberalatus the basal tooth can be vestigial, visible just as a slightly rounded projection. GARRISON (1982) has suggested that the tooth can show variations in size and that these variations are geographical [i. e. A. latialatus ( GARRISON, 1982: 10)]. The paraproct is, in A. chocoanus , underdeveloped, as in A. guayaraca , A. tuberalatus and A. latialatus . The character which most closely relates A. chocoanus with A. latialatus is, however, the acute and curved cercus ( GARRISON, 1982: fig. 22), being notoriously longest in A. chocoanus . Marginal cell after quadrangle is in A. chocoanus longer and narrower than in all other species described to date, but most similar to A. grandis ( RAMBUR, 1842) and A. regalis ( GLOYD, 1944).

In color pattern, A. chocoanus comes close to A. neblina GARRISON, 1982, nonetheless it is important to note that on mesepisternum A. chocoanus has the green stripe complete, whereas A. neblina has a thin stripe bordered by the posterior pleural suture. Also in A. neblina the metasternum is largely black while in A. chocoanus it is mostly yellow, resembling A. guayaraca . Posterior hamule bear a short and rounded tip, as in A. guayaraca . The genital ligula of A. chocoanus (ligula ovate with ventral arm not touching tip) belongs to group 3 as proposed by GARRISON (1982), although the post-mortem variation of this structure is suspected to be particularly problematic when defining intrageneric groups. In the two A. chocoanus males examined, the ventral arm is in contact with the tip of the ligula.

FINAL REMARKS. − The specimens of this colorful species were collected in a secondary forest. Days before our visit to the locality, according to our guide, there was a bulldozer opening way through the dense forest. This destructive practice is conducted to determine locations of new platinum prospecting camps and for introducing machinery. We ingressed through one of these roads, and there we had the first sighting of A. chocoanus , perched on leaves, ca 2 m above ground, of about 10 m high Sapotaceae and Bombacaceae trees. The violent and powerful flight of this species is noteworthy, and detection of two males was possible thanks to the audible impact produced when they landed on leaves of woody vegetation. Their evasive behavior, flying to the trees tops when disturbed, is also uncommon in the genus.

In July 2007 and July 2010, two more expeditions were carried out to the area in order to find the larva, but without success. Adults were not seen either. Unfortunately, the progressive loss of forest, due to mining activities and timbering practiced by the “colonos”, makes the rediscovery of the species at the type locality most unlikely. Future efforts must be made to determine the extent of its distribution range. Provisionally it is considered here as an endemic element of biogeographic Chocó.

Figures

Fig. 1. Archilestes chocoanus sp. n., male holotype: (a) head, dorsal view; − (b) pterothorax, dorsal view; − (c) same, ventral view; − (d) pterothorax and abdominal segments 1 and 2 showing color pattern, right lateral view.

Fig. 2. Archilestes chocoanus sp.n., male holotype:(a) pos- terior right leg; − (b) left wings, ventral view; − (c) left posterior hamule, right lateral view; − (d) genital ligula, right lateral view;− (e) same, distal portion, ventral view; − (f) same, dorsal view.

Fig. 3. Fig. 3. Archilestes chocoanus sp. n. [Figs a-c: male holotype, Fig. d: female allotype]: (a) distal portion of abdomen, lateral view; − (b) right circus, dorsal view (right), ventral view (left); − (c) paraprocts and right circus, ventral view; − (d) distal portion of abdomen, left lateral view.