Argia tennesseni Garrison & von Ellenrieder, 2018

Garrison, Rosser W. & Ellenrieder, Natalia Von, 2018, Damselflies of the genus Argia (Odonata: Coenagrionidae) from Ecuador with descriptions of five new species, Zootaxa 4470 (1), pp. 1-69 : 34-36

Argia tennesseni Garrison & von Ellenrieder , n. sp.

Figs. 22 (head, thorax, S1– 3 ♂), 33 (head, thorax, S1– 3 ♀), 57, 58 (S8– 10 ♂), 68 (S7– 10 ♀), 84 (mesostigmal plates ♀), 101 (genital ligula), 121 (appendages ♂), 127 (wings, ♂), 138, 141 (map), 150, 151 (photos).

Etymology. Named tennesseni (Latinized name) in honor of our friend and colleague Kenneth J. Tennessen who first brought this interesting species to our attention.

Types. Holotype ♂: ECUADOR, Orellana Prov.: stream 8.5 km east of Loreto , 0°37'6" S, 77°17'42" W, 360 m, 14 September 1997, Kenneth J. Tennessen leg. [ FSCA].

Specimens examined (all paratypes). 17 ♂♂, 26 ♀♀. ECUADOR : Sucumbios Prov.: 1 ♀, Limoncocha , forest stream (0°24' S, 76°36' W, 300 m), 1 March 1972, David L. Pearson leg. [ DRP]; same data but 1 ♂, 6 March 1972 [ DRP]; same data but 1 ♂, 9 March 1972 [ DRP] ; Orellana Prov.: 1 ♂, 2 ♀♀, 12 km NE of Loreto, stream (0°37'18'' S, 77°15'36'' W, 370 m), 15 October 2009, Kenneth J. Tennessen leg. [ FSCA]; same data but 1 ♂, 2 ♀♀, 12.5 km NE of Loreto, 12 October 2009 [ FSCA]; same data but 1 ♂, 12.5 km NE of Loreto (reared; adult in ETOH) [ FSCA]; 1 ♀, Yasuni National Park, stream on road to Waorani Reserve , 1.8 km west of Waorani Reserve Road , on Markus Oil Co. Road PC 29-30, small stream (0°42' S, 76°28' W, 200 m), 16 November 1997, William F. Mauffray leg. [ FSCA]; 2 ♂♂, 1 ♀, same data but stream on road to Waorani Reserve , 6.2 km south of main Yasuni Road (0°42'43'' S, 76°28'28'' W, 230 m), 10 June 1995, Kenneth J. Tennessen leg. [ FSCA]; same data but 1 ♂ [ RWG]; 1 ♀, Scientific Research Station , Yasuni National Park , stream at km 29 on Yasuni Road, 20.5 km north of station, Collected under Permit No. 027 1C INEFAN/DNANVS {0°34'8'' S, 76°30'59'' W, 220 m}, 11 June 1995, Sidney W. Dunkle leg. [ RWG]; 1 ♀, small stream ca 12 km north of Loreto, route E20 (0°37'18'' S, 77°15'36'' W, 367 m), 3 November 2013, Kenneth J. Tennessen leg. [ RWG]; 1 ♂, 3 ♀♀, same data but [ FSCA]; 1 ♂, small stream west of Coca (north of route E20) (0°27'45'' S, 77°8'10'' W, 282 m), 30 October 2013 [ FSCA]; 1 ♂, 1 ♀, Tiputini Biodiversity Station (0°38' S, 76°9' W, 220 m), 20 September 2000, Kelly Jackson, D. Inward leg. [ BMNH]; same data but 1 ♀ [ RWG]; 1 ♀, Tiputini Biodiversity Station USFQ, black water stream crossing Guacamayo trail at marker 2050 (0°38'18'' S, 76°8'57'' W), 17 January 2009, R.W. Garrison & N. von Ellenrieder leg. [ CSCA]; 1 ♀, same data but [ RWG]; 1 ♀, Tiputini Biodiversity Station USFQ, Guacamayo trail between markers 450–2100 (0°38'6'' S, 76°9'12'' W, 237 m), 22 January 2009 [ RWG]; 1 ♀, Tiputini Biodiversity Station USFQ, stream crossing Chorongo trail at marker 225 (0°38'6'' S, 76°9'1'' W, 220 m), 16 January 2009 [ CSCA]; 1 ♂, 3 ♀♀, same data but [ RWG]; 1 ♀, same data but 18 January 2009 [ CSCA]; 1 ♂, 2 ♀♀, same data but [ RWG]; 1 ♀, Tiputini Biodiversity Station USFQ, stream crossing Matapalo trail at marker 450 (0°38'13'' S, 76°8'45'' W, 245 m), 14 January 2009 [ RWG]; 1 ♂, Tiputini Biodiversity Station , near Yasuni National Park , Canopy fogging project, Lot #1908, TR1 #9, terra firme forest (0°37'55'' S, 76°8'39'' W, 220 m), 23 October 1999, Terry L. Erwin et. al leg. [ USNM] ; Napo Prov.: 1 ♂, Cotopino River (?between Napo and Aguaricos ) {1°0' S, 78°42' W, 400 m}, 14 March 1950, William Clarke-Macintyre leg. [ UMMZ] . PERU, Loreto Reg.: 1 ♂, Yurimaguas {5°53'49'' S, 76°6'53'' W, 140 m}, March 1940, Guillermo G. Klug leg. [ UMMZ] . BRAZIL, Acre State: 1 ♂, Igarapé da Mato Grosso, 5 km north of Tejo River {8°13'0'' S, 71°41'0'' W, 240 m}, 6 July 1993 [ FSCA] .

A dark medium-sized sexually dimorphic species with male thorax larger and bulkier than in other Argia species, heavily infumated wings ( Fig. 127 ) and male epiproct confluent with torifer ( Fig. 121b, c ).

Description of male holotype. Head as in Fig. 22 , entirely matte black except for following dark brown areas: base of mandibles, genae and base of labrum, epicranium with small pale spot anterolateral to lateral ocellus, and large violaceous postocular spot laterally not confluent with eye; occipital bar black, rear of head entirely black.

Prothorax entirely black with slight metallic luster; synthorax as in Fig. 22 , mostly black with an inverted wedge-shaped violaceous purple antehumeral stripe adjacent to humeral suture, its base about 0.20 as wide as black middorsal stripe; mesepimeron and mesinfraepisternum matte black, a narrow orange brown mesopleural stripe followed by a broad matte black metapleural stripe, posterior portion of metepimeron orange brown, its posterior border black, venter of thorax mostly black with ill-defined orange-brown spot medially.

Wings infumated with brown, venation black; pterostigma dark brown, surmounting 2.0 cells in all wings; postnodals Fw 19/19, Hw 17/17; postquadrangular cells Fw 5/5, Hw 4/4; RP 2 at Fw 7.5/7.5, Hw 6/6. Coxae black washed with orange-brown on posterior margins, trochanters and remainder of legs and armature black.

Abdomen (as in Fig. 22 , Fig. 57) mostly black; S1 black with an ill-defined orange-brown lateral spot; S2 entirely black with a small ill-defined lateral black spot above lateral margin; S3–7 black with a wash of brown at basal ring, S8 black except for violaceous dorsal spot at apical sixth, S9 violaceous dorsally, black laterally, S10 black except for narrow transverse violaceous dorsal spot at apical half (Fig. 57); torus brown, remainder of torifer, epiproct and appendages black.

Genital ligula ( Fig. 101 ), lacking microspinulate patch on ental surface proximal to flexure on sclerotized area; distal segment largely membranous armed basally with a curved sclerotized flagellum and laterally with a semitransparent glabrous parallel-sided lobe. Torus small, transversely oval, swollen, occupying outer half of torifer ( Fig. 121b ); epiproct bilobed with apical margin forming a raised ridge, confluent laterally and anteriorly with torifer thus forming a largely transverse triangular plate ( Fig. 121b ); cercus ( Fig. 121a, c ) subequal in length to paraproct, robust, slightly longer than wide, swollen basally divided apically with outer branch narrowing distally and in mediodorsal view, with concave ventral surface; inner branch a slightly recesses robust decumbent conical tooth best seen in mediodorsal view ( Fig. 121c ); paraproct bilobate, almost quadrate in lateral view with upper and lower branches broadly divided, their tips bluntly triangular, small and both approximately the same size ( Fig. 121a ).

Dimensions. Hw 21.5, abdomen 28.0, total length 32.0.

Description of female paratype ( Ecuador: Orellana Prov., Yasuni National Park, stream on road to Waorani Reserve, 6.2 km south of main Yasuni Road).

Head (as in Fig. 33 ) entirely black with a small ivory white spot on gena confluent with eye margin, a small diagonal spot anterolateral to median ocellus and a tan postocular spot not confluent with eye margin; rear of head entirely black. Prothorax matte black except for narrow orange transverse stripe on anterior lobe and ventral margin of propleuron; synthorax as in Fig. 33 , mostly black with narrow orange antehumeral stripe gradually narrowing dorsally, adjacent to humeral suture, its base about one fifth as wide as black middorsal stripe; mesepimeron and mesinfraepisternum matte black, an orange brown mesopleural stripe as broad matte black metapleural stripe, posterior portion of metepimeron orange brown, its posterior border washed with brown, venter of thorax mostly light brown.

S1 black with a pale orange lateral spot; S2 black with ventral margin washed with orange brown; remainder of abdomen including ovipositor and cercus black (as in Fig. 68).

Mesostigmal lobe small, forming a slightly raised gently arcuate lobe confined to medial half of mesostigmal plate, area immediately behind obsolete posterior margin of mesostigmal plate unmodified ( Fig. 84 ).

Variation in paratypes. The purple antehumeral stripe in male varies in size and is completely absent in the male from Brazil. The pale lateral spot on S 10 in male ranges from present as in holotype (Fig. 57) to very small (1.0 km NW Lita, Fig. 58). Pterostigma surmounting 1–2 cells in males, 1 in female; postnodals: Fw 16–18 in males, 12– 12 in female, Hw 14–16 in males, 10– 10 in female; postquadrangular cells Fw 3–5, Hw 3–4 in males, Fw 3–3, Hw 3– 3 in female; RP 2 at Fw 7–9, Hw 6–7 in males, Fw 6–6, Hw 4– 4 in female. Dimensions. ♂: Hw 20.9 ± 1.09 [19–22.3], abdomen 27.3 ± 1.22 [25.7–29.3], total length 35.2 ± 1.51 [33.3–37.8]; ♀: Hw 20.5, abdomen 25.0, total length 31.5.

Diagnosis. Male unlike any of other species of Argia . Robust thorax, inverted wedge-shaped violaceous purple antehumeral stripe (when present) contrasting with orange brown lateral thoracic stripes (as in Figs. 22 , 150 ), heavily infumated wings, supernumerary postquadrangular cells (as in Fig. 127 , shared with A. philipi ) and morphology of the male caudal appendages ( Fig. 121 ) coupled with torifer confluent with epiproct are unique to this species. Female easily distinguished by orange-brown pale coloration coupled with the supernumerary postquadrangular cells. Within its range, female may be confused only with female of Argia difficilis Selys ( Fig. 138 ) but in the female of that species pale areas are violaceous (orange brown in A. tennesseni ), there are fewer postquadrangular cells (generally 4 in FW, 3 in HW in A. difficilis ; generally 5 in FW, 4 in HW in A. tennesseni ), and wings are hyaline (infumated in A. tennesseni ).

Remarks. Little variation was observed among paratypes. One male ( Brazil: Acre State, Igarapé da Mato Grosso, 5 km north of Tejo River) lacked the violaceous antehumeral stripe. Some females possess a small orange spot above the propleuron, pale lateral (mesopleural and metapleural) stripes in some males and females appear to be dull blue or olive-green as is shown for a pair labeled as Argia sp. K at the Dragonflies and Damselflies of Ecuador ( Odonata ) website (http://bdei2.cs.umb.edu/~whaber/ Odonata _of_ Ecuador /index.html) managed by Bill Haber and David Wagner. Males often lack the small pale spot on S8 (Fig. 58) present in the holotype (Fig. 57).

This species is remarkable in being sexually dimorphic; male thorax is uniquely robust reminiscent of some species of the Papuan genus Palaiargia Förster , and is comparatively larger and bulkier ( Figs. 22 , 150 ) than in the female ( Fig. 33 , 151 ).

Habitat. Confined to small, mostly shaded creeks in jungle understory. At the Tiputini Biodiversity Station in January, 2009, we observed adults in company with A. difficili s Selys. Both species were collected while perching on leaves exposed to sunlight in deep forest. Fewer males of A. tennesseni were seen compared to females. We observed (and photographed) an unaccompanied female ovipositing on a partially submerged twig in a small creek. A male in poor condition was collected by Terry Erwin during a canopy fogging project at Tiputini in October, 1999, indicating that this species may roost in the canopy. The species is apparently a denizen of small mostly shaded streams in Amazonian regions of Ecuador, Peru and western Brazil.

Distribution. Thus far known from Napo, Orellana and Sucumbios provinces of eastern Ecuador ( Fig. 138 ), Loreto Region in Peru and Acre State in Brazil ( Fig. 141 ).

Figures

FIGURES 19–22. Color pattern of male head, thorax, and S1–4. Head, dorsal view, thorax and S1–4, lateral view.

FIGURES 123–127. Male caudal appendages (123–126) and wings ♂ (127). (a) dorsal view; (b) ventral view.

FIGURES 119–122. Male caudal appendages. (a) lateral view; (b) dorsal view; (c) mediodorsal view; (d) ventral view.

FIGURES 98–102. Genital ligula. (a) lateral view; (b) ectal view; (c) entolateral view; (d) detail, lateral view.

FIGURES 28–33. Color pattern of female. Head, thorax, and S1–4 (31–33); pterothorax (28–30). Head, dorsal view, thorax and S1–4, lateral view.

FIGURES 84–88. Female mesostigmal plates. (a) dorsal view; (b) detail of mesostigmal lobe, dorsal view; (c) frontal (anterior) view; (d) posterior view; (e) detail of mesostigmal lobe, anterior view; (f) detail of mesostigmal lobe, posterodorsal view (on edge).

FIGURES 149–151. Field photographs of Ecuadorian Argia species. (149) A. selysi, 5 km west of Orellana Prov. border, Napo Prov., Ecuador, 11 October 2009; (150) A. tennesseni, male from 12 km east of Loreto, Orellana Prov., Ecuador, 12 October 2009; (151) A. tennesseni, female from 12 km east of Loreto, Orellana Prov., Ecuador, 12 October 2009. Photographs (149– 151) by Jim Johnson.

FIGURES 138–139. Distribution of new Argia species and closest congeners in Ecuador.

FIGURES 140–141. Distribution of new Argia species and closest congeners in Ecuador.