Epigomphus pechumani Belle 1970
Creators: name: Bota-Sierra, Cornelio A.
name: Novelo-Gutiérrez, Rodolfo
name: Amaya-Vallejo, Vanessa
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Odonata
Gomphidae
Epigomphus
Epigomphus pechumani

description: Epigomphus pechumani Belle, 1970
Figures 1 a–c, 2a–g, 3a–g, 4.
Material deposited at CEUA: 16 males and 2 females. 1 ♀: COLOMBIA, Risaralda Department, Pueblo Rico Municipality, Santa Cecilia, Alto Amurrupa reserve, Ranas de Cristal Creek (N 5.32033° W 76.17357°; elev. 650 m), 7 February 2017, C. Bota & J. Sandoval leg. 3♂, Same data except (N 5.33003° W 76.14935°, elev. 405m) 4, 17 and 21 February 2017. 1♂, El Silencio township (N 5.35405° W 76.13991°, elev. 530m), 10 February 2017, B. Cárdenas, J. Sandoval & C. Bota leg. 1♀, PNN Tatamá, Montebello township, small arm of the Taiba River (N 5.22021° W 76.08099°, elev. 1430 m), 18 May–25 June 2015, J. Forero, R. Rodríguez & C. Bota. Same data except: 1♂, 25 July 2016, J. Sandoval & C. Bota leg. 2♂ May–June 2015, J. Forero, R. Rodríguez & C. Bota leg. 1♂, 19 June 2016, A. Orejuela & C. Bota leg. 2♂, 25 July 2016, F. García, J. Sandoval & C. Bota leg. 3♂, 16 August 2016 J. Sandoval & C. Bota. 2♂, El Pencil area (N 5.24813° W 76.08253° 1170), 18–25 April 2015, C. Bota leg. 1♂ Valle del Cauca Department, Farallones de Cali National Park, Dagua Municipality, Anchicayá, Hydroelectric Facility, road to La Riqueza (N 3.59651°, W 76.89001°, elev. 551 m), 18 October 2016, C. Flores & C. Bota leg.
Redescription. Male: Medium size dragonfly, in life thorax brown with creamy pale stripes (Figs. 1 a–b), (greenish-yellow in preserved material); abdomen blackish-brown with creamy pale spots (Fig. 1 a), (greenishyellow in preserved material; abdominal appendages strongly robust.
Head. Eyes in life brilliant blue (Fig. 1 a–b); labium cream colored, grayish-blue medially, with long dark setae; base of mandibles, genae pale bluish; labrum (as in Fig. 1 b) blackish-brown with a large, rounded pale blue, spot on each side; anteclypeus dark brown, postclypeus dark brown, with two pale yellow spots, one on each side; frons dark brown with a large, transverse, dorsal blue spot on each side of midline, not contiguous (Figs. 1 a–b, 2a); antennae dark brown. Vertex and occiput dark brown, with one pale stripe behind each lateral ocellus (Fig. 2 a), rear of head yellowish-brown (Fig. 2 a); occiput (Fig. 2 a) thick and swollen at sides, with long, scattered brown setae along entire width, posterior surface undulate. Rear of head moderately tumid near upper margin of compound eyes (Fig. 2 a).
Thorax. Pronotum (Fig. 2 a) with anterior and middle lobes mostly light brown, middle lobe pale yellow laterally, and a small yellow, twin-spot on middorsum; posterior lobe brown with long, brown erect setae. Pterothorax (Figs. 1 a–b) dark brown with greenish-yellow pale stripes; anterior, transverse mesothoracic keel (collar) with minute spinules; middorsal carina usually brown, sometimes with pale dashes, mesepisternum brown with first antehumeral pale stripe not connected to pale collar anteriorly, not reaching antealar crest posteriorly; second pale antehumeral stripe represented only by one (upper) or two small pale spots, one inferior spot close to mesothoracic collar, one superior spot close to antealar crest; mesepimeron dark brown with a pale stripe more or less of same width its full-length, bifurcating at superior end and touching antealar crest, occasionally connected superiorly to metepisternal pale stripe by a very thin pale line; metepisternum and metepimeron mostly pale with a brown stripe on metapleural suture; venter of pterothorax pale, grayish-yellow. Coxae greenish-yellow; femora with basal 0.65 of external (dorsal) surface light brown, distal 0.35 black; tibiae and tarsi black, pretarsal claws reddish brown with distinct supplementary tooth; femur spines short on ventral surface (Fig. 2 f); protibiae with modified spines (scale-like) on distal half of anterior (internal) border, without lamina tibialis (Figs. 2 a, g); mesotibia with long, slender spines on anterior and posterior borders, metatibia with long, slender spines on posterior (external) border, anterior (internal) border with a row of peg-like spines (Fig. 2 f); pro- and mesotarsi with slender spines, first and second tarsomeres of metatarsi with slender spines on posterior (external) border and peg-like- spines on anterior (internal) border, third tarsomere with slender spines on both borders (Fig. 2 f). Wings slightly tinged brown. Venation dark brown; width of hindwing 0.28 its length. Basal subcostal crossvein present (one male with two crossveins on left Fw). Second primary antenodal crossvein 7th in Fw, 6th or 7th in Hw. Antenodal crossveins: Fw 19–20 (left), 18–21 (right); Hw 14–16. Postnodal crossveins: Fw 12–17; Hw 12–15. Three to four (Fw) and two (Hw) cubito-anal crossveins in addition to inner side of subtriangle. Crossveins in space between sectors of arculus and point of branching of RP on Hw 3 (right) or 4 (left). Supratriangles, triangles and subtriangles free from crossevins. Pterostigma reddish-brown, covering about 6.5–7 (left), 6 (right) cells in Fw, 6 (left), 5.5–7 (right) cells in Hw.
Abdomen (Fig. 1 a). Predominantly blackish-brown. Width of S1 3 mm, S2 posterior to auricles 2 mm, S3–7 slender (1.5– 1.2 mm) widening at S8 from 1.7 mm at base to 3.2 mm posteriorly, S9 3.0 –3.3, S10 3.0 – 3.7 mm wide. S1–2 pale greenish-yellow, brown on dorsum except for a narrow pale yellow mid-dorsal stripe; auricle of S2 swollen on dorsal half with a transverse, thick, incomplete ridge at middle, posterior surface with about five vertical rows of small, stout spines; S3–5 with a narrow, pale yellow mid-dorsal line, S6 only with a pale, basodorsal spot; sides of S3 with a latero-basal greenish-yellow triangle at basal 3/4 length of segment, interrupted at its half by dark brown at submedian transverse carina; sides of S4–6 with a basolateral, rectangular greenishyellow spot at basal 0.30 of each segment; S7 dorsally pale on basal 0.50, laterally pale on basal 0.70, remaining blackish-brown; S8–9 blackish brown, S10 reddish-brown dorsally, armed with black spinules, brown with a large, semicircular, mediobasal yellow spot on venter (Fig. 3 a). Anterior hamule hidden below posterior hamule, dark brown, short, divided at upper half, upper and lower branches hook-like (Fig. 2 c); posterior hamule thick (Fig. 2 c), directed caudoventrally, anterior surface with rows of small black denticles, latero-external surface with long, brown bristle-like setae, apex widely rounded. Vesica spermalis (Figs. 2 c–d): segment 1 brown, triangular, its ventral surface deeply concave, borders thick (Fig. 2 c); segment 2 reddish-brown; segment 3 (Fig. 2 d) reddishbrown on basal 0.60, apical 0.40 whitish, ending posteriorly in two triangular, roundly pointed horns directed ventrally; segment 4 (Fig. 2 d) the shortest, prepuce rounded and diaphanous, lateral lobe strongly bulging dorsally, with a slender projection directed posteriorly and parallel to cornua; cornua short. Cercus (Figs. 3 a–d) dark reddish-brown; in dorsal view (Fig. 3 c) widening gradually to apex, extreme base with a small tooth on internal margin directed medially, medial margin slightly concave and longer than external margin, inner apical angle widely rounded, outer apical angle obtuse; cercus in ventrolateral view (Fig. 3 a) wider basally, gradually narrowing to apex, dorsal margin slightly convex at basal 0.80 then abruptly and strongly decurved at apical 0.20 ending in a strong tooth, dorsal surface on apical 0.20 with a large, shallow depression; ventral margin concave with a ventral, stout tooth at basal 0.80, distal margin of cercus notched between both teeth; cercus in caudal view as in Fig. 3 d. Epiproct (Figs. 3 a–d) blackish-brown, widely V-shaped, slightly longer than cerci (Fig. 3 c); branches of epiproct, in dorsal view (Fig. 3 c), with surface deeply concave at basal 0.60, thick on apical 0.40; in mediodorsal view (Fig. 3 b), ending in a spine directed dorsally, and with a dorsal, subapical, triangular stout tooth; in ventrolateral view with a stout, rounded, baso-ventral tooth (Fig. 3 a).
Measurements (mm). TL 48–57, Ab 36–44, FwL 33–38, HwL 31–37, FwPt 3.2–4, HwPt 3.5–4.3, Hw width at nodus 8–9.5, head width 7.3–7.9, Hf 6.8–7.1, cercus 2.1–2.4.
Female: Medium size dragonfly, in life thorax brown with creamy pale stripes (Fig. 1 c), (dull green in preserved material); abdomen blackish-brown, in life with creamy pale spots (yellowish-green preserved material).
Head. As in male but base of mandibles greenish-yellow; labrum brown with a large, rounded pale green, spot on each side; anteclypeus brown, postclypeus brown with anterolateral corners black; frons brown with a grayish spot on antero-dorsal corners (Fig. 2 b). Vertex and occiput reddish-brown (Fig. 2 b), rear of head mostly yellowishbrown becoming blackish-brown above; vertex with a concavity behind each lateral ocellus, and a pair of low posteromedial tubercles (Fig. 2 b); occiput with one dorsal conical tubercle on each side, posterior surface undulate (Fig. 2 b). Rear of head strongly tumid near upper margin of compound eyes, with a vertical, external postgenal groove on each side that likely receives the male cerci, during copulation as stated by Calvert (1920).
Thorax. As described for male but second pale antehumeral stripe represented only by one small pale superior spot close to the antealar crest (Fig. 1 c). Coxae grayish; femoral spines long and slender, apical spine of external border largest; metatibia with long, slender spines on both inner and outer border; all metatarsomeres with slender spines on both sides. Wings hyaline. Width of hind wing 0.24 its length (right Hw broken and lost). Basal subcostal crossvein present. Second primary antenodal crossvein 6th or 7th in Fw (left), 6th or 8th (right), 6th or 7th in Hw (left). Antenodal crossveins: Fw 18 or 21 (left), 21 or 23 (right); Hw 14 or 15 (left). Postnodal crossveins: Fw 14; Hw 13 (left) or 16. Three (Fw) and two (Hw) cubito anal crossveins in addition to inner side of subtriangle. Pterostigma reddish-brown, covering about 8 cells in Fw, 6.5 cells in Hw (left).
Abdomen (Fig. 1 c). Predominantly blackish-brown, slender, as described for male but S1 pale greenish-yellow, brown on dorsum except for a narrow pale yellow mid-dorsal stripe; S2 mostly dark with a narrow a pale yellow mid-dorsal line, a lateral, longitudinal greenish-yellow stripe the full-length of segment; auricle of S2 swollen, rounded, smooth; sides of S4–6 with a basolateral, triangular greenish-yellow spot at basal 0.30 of each segment; S7 dorsally pale on basal 0.35, laterally pale on basal 0.25, remaining blackish-brown; S8–10 black. Vulvar lamina (Fig. 3 e), in ventral view, V-shaped, reaching basal 0.44 length of lateral margin of S9, branches splitting at basal 0.60 length of vulvar lamina, tips rounded. Cerci black, left cercus with dorsal and ventral margins parallel on basal 0.70, strongly convergent distally ending in a sharply pointed tip (Fig. 3 f); right cercus with dorsal margin irregular and strongly convex on basal 0.75, then converging linearly forming a large, sharply pointed tip (Fig. 3 g) (probably representing a deformity). Epiproct black, in dorsal view triangular, roundly pointed, polished dorsally, with long, stiff bristles on ventral surface, about as long as cerci (Figs. 3 f–g).
Measurements (mm). TL 57.7–58, AL 44.3–44.5, Fw 41.5–42.0, Hw 39.0–39.5, Hw width at nodus 9.5, Fw Pt 4–4.2, Hw Pt 4.5, head width 8.2, Hf 6.2–6.5, cercus 0.9–1.0, vulvar lamina 0.5–0.7.
Remarks. Epigomphus pechumani belongs to the group of species with the second antehumeral stripe reduced to one or two spots. Belle (1970) considered E. crepidus Kennedy, 1936, as the nearest ally of E. pechumani with no supporting information. We do not agree with Belle’s point of view, both species are quite different in many respects, mainly on: occiput thicker and tumid in E. pechumani; second antehumeral stripe complete in E. crepidus; anterior lamina wider and more extended laterally in E. crepidus; inferior hook of anterior hamuli well developed in E. pechumani; segment 1 of vesica spermalis ventrally deeper in E. pechumani; S10 and caudal appendages are more robust and bulky in E. pechumani; epiproct quite larger than cerci in E. crepidus; epiproct branches widely separated each other, slender and narrower in E. crepidus; both species are more or less alike only in the shape of cerci. We consider it premature to establish relationships among species pending a generic revision including all known species. However, E. pechumani can be distinguished from other species by the following combination of features: second pale antehumeral stripe reduced to two pale spots (upper and inferior) (Figs. 1 a–b); anterior hamuli divided at upper half, upper and lower branches hook-like (Fig. 2 c); cercus (Figs. 3 a–d), in dorsal view, widening gradually to apex with the inner apical angle widely rounded, and outer apical angle obtusely produced; in caudal view, with distal margin notched between two teeth; branches of epiproct in dorsal view with surface deeply concave at basal 0.60, ending in a spine directed dorsally, and with a dorsal, subapical, triangular stout tooth.
Biology. Males of this species were seen during sunny days along little branches of the rivers perching on branches or standing on stones and guarding territories (Fig. 1 a); they were also observed on first order streams inside forest or at forest edge. Some were collected during bright sunny days perching on the ground in trails inside the forest. Females were rarely seen; only three were seen during more than one year of field sampling; we suspect they probably forage high in the forest canopy and rarely descend to the ground.
Distribution. Epigomphus pechumani is recorded at only three localities on the Pacific slope of the western Colombian Andes, Cordillera Occidental, between 400 and 1400 m above sea level, in the departments of Risaralda and Valle del Cauca (Fig. 4).
description: Published as part of Bota-Sierra, Cornelio A., Novelo-Gutiérrez, Rodolfo & Amaya-Vallejo, Vanessa, 2017, The rediscovery and redescription of Epigomphus pechumani Belle, 1970 (Odonata: Gomphidae), with a description of its female from the Western Colombian Andes, pp. 419-427 in Zootaxa 4306 (3) on pages 420-426, DOI: 10.11646/zootaxa.4306.3.8, http://zenodo.org/record/844536