Argia philipi 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 : 24-28

Argia philipi Garrison & von Ellenrieder , new species

Figs. 5 (head ♀), 20 (head, thorax, S1– 3 ♂), 31 (head, thorax, S1– 3 ♀), 55 (S7– 10 ♂), 65 (S7– 10 ♀), 66 (S1– 5 ♀), 82 (mesostigmal plates ♀), 100 (genital ligula), 119 (appendages ♂), 139, 141 (map), 148 (field photo).

Argia sp. nr cuprea [undescribed] Butt 1995: 96 (Tambopata, Peru)

Argia cuprea (Gloyd #43a): Louton et al. 1996: 371 (Pakitza, Peru).

Etymology. Named philipi (Latinized name) in honor of the senior author's son Philip Alexander Garrison who has given him much enjoyment and companionship over the years.

Types. Holotype ♂: BOLIVIA, Cochabamba Dept., Chapare Prov.: stream 5 km south of Villa Tunari , noon (16°59'49" S, 65°24'28" W, 350 m), 4 November 2001, Jerrell J. Daigle leg. [ FSCA].

Specimens examined (all paratypes). 226 ♂♂, 84 ♀♀. COLOMBIA , Caquetá Dept.: 2 ♂♂, 2 ♀♀ Puerto Abeja, Stream #3, north of Araracuara (0°4'44'' N, 72°26'50'' W), 3 July 1996, Gordon Pritchard, Jacek Zloty leg. [ RWG] . ECUADOR, Napo Prov.: 2 ♂♂, 1 ♀, Concepción- Napo River, {1°40' S, 77°25' W, 400 m}, 28 December 1939, William Clarke-Macintyre leg. [ RWG]; same data but 3 ♂♂ [ UMMZ]; same data but 4 ♂♂, 29 December 1939 [ UMMZ]; 1 ♂, Cotopino {1°0' S, 78°42' W}, February 1950 [ MCZ]; 1 ♂, Hacienda Ila, Anzu River, {1°12' S, 77°50' W}, 700 m, 24 December 1936, [ UMMZ]; 2 ♂♂, Jatun Sacha Biological Sta., 23 km east of Puerto Napo–Tropical wet forest, streams above flood plain; eyes red/tan; on largest stream, about 5 m wide (1°3'0'' S, 77°47'0'' W, 522 m), 17 October 1988, Sidney W. Dunkle leg. [ RWG]; 1 ♂, Jatun Yacu , Napo River watershed, {1°1'0'' S, 77°50'0'' W, 700 m}, 7 April 1935, William Clarke-Macintyre leg. [ RWG]; 1 ♂, same data but 11 April 1935 [ CSCA]; 1 ♂, same data but [ UMMZ]; 1 ♂, same data but, 13 April 1935 [ RWG]; 1 ♂, same data but [ UMMZ]; 1 ♂, same data but 24 August 1935 [ UMMZ]; 2 ♂♂, same data but 12 February 1937 [ CSCA]; 2 ♂♂, same data but [ RWG]; 3 ♂♂, same data but [ UMMZ]; 2 ♂♂ same data but, 22 February 1937 [ RWG]; 1 ♂, same data but 20 March 1937 [ CSCA]; 1 ♂, same data but [ UMMZ]; 1 ♂, same data but 7 April 1937 [ CSCA]; 2 ♂♂, same data but April 1937 [ BMNH]; 2 ♂♂, same data but March 1937 [ CSCA]; 1 ♂, 1 ♀, same data but April 1937 [ CSCA]; 2 ♂♂, same data but [ MCZ]; 2 ♂♂, same data but March 1937 [ RWG]; 4 ♂♂, 1 ♀, same data but April 1937 [ RWG]; 10 ♂♂, same data but March 1937 [ UMMZ]; 1 ♂, same data but April 1937 [ UMMZ]; 1 ♂, 1 ♀, Las Palmas, Anzu River , Napo River watershed , {1°4' S, 77°48' W, 900 m}, 16 August 1935 [ CSCA]; 1 ♂ , Napo River watershed {1°3'0'' S, 77°47'0'' W, 522 m}, 3 March 1934 [ UMMZ]; 1 ♂, same data but 15 March 1934 [ CSCA]; 3 ♂♂, same data but 18 March 1934 [ RWG]; 4 ♂♂, 1 ♀, same data but [ UMMZ]; same data but May 1940 [ CSCA]; 2 ♂♂ same data but [ UMMZ]; 2 ♂♂, Quebrada Churi-yacu, near Misahualli , Upper Napo, {1°2'0'' S, 77°41'0'' W, 500 m}, July 1942 [ UMMZ]; 1 ♂, Anzu River (vicinity of Napo) {1°3'9'' S, 77°48'12'' W, 900 m}, 9 October 1934 [ BMNH]; 1 ♂, 1 ♂, Pacai-Yacu River (? Paciyacu) nr. Concepción , Napo River watershed , {1°40' S, 77°25' W, 400 m}, 29 December 1939 [ UMMZ]; 1 ♂, 1 ♀, Upper east branch of Ishpinga-yacu , Napo {0°59'20'' S, 77°50'12'' W, 500 m}, 18 September 1942 [ RWG]; 1 ♂, same data but [ UMMZ]; 2 ♂♂, 1 ♀, Upper Ila River , Napo River watershed , {1°12' S, 77°50' W, 700 m}, 21 November 1934 [ RWG] ; Sucumbios Prov.: 1 ♂, road, 3 km NW of Shushufindi (0°9'59'' S, 76°41'30'' W, 280 m), 13 May 2009 [ FSCA] ; Orellana Prov.: 2 ♂♂, small stream ca 12 km northeast of Loreto, Route E20 (0°37'18'' S, 77°15'3'' W, 365 m), 12 October 2009, Kenneth J. Tennessen leg. [ FSCA]; 1 ♂, small streams and forest trails 12 km east of Loreto , 2 km south of highway 45; 2009-0225 (0°37'18'' S, 77°15'36'' W), Jim Johnson leg. [ JJ] ; Pastaza Prov.: 1 ♀, near Shell, trails, forest, and Metolo River, at Los Copales (1°29'31'' S, 78°4'21'' W, 1,080 m), 20 September 2005, Kenneth J. Tennessen leg. [ FSCA] ; Morona Santiago Prov.: 1 ♀, Gualaquiza (specimen probably from Calvert collection originally) {3°24'23'' S, 78°34'18'' W, 800 m}, April–May 1935, F. Campos R. leg. [ FSCA]; 1 ♂, Mangosisa , Upano River . received 28 September 1945 {2°31'28'' S, 77°53'41'' W, 708 m}, Leopoldo Gomez leg. [ RWG] . PERU, Ayacucho Reg.: 1 ♂, Sivia , Apurimac River {12°30'45'' S, 73°51'28'' W, 760 m} 14 June 1941, Felix Woytkowski leg. [ UMMZ] ; Huánuco Reg.: 2 ♂♂, 10 km north of Cucharas, confluence of Huallaga and Pacay rivers {9°5' S, 76°4' W, 500 m}, August 1954 [ RWG]; 2 ♂♂, same data but [ UMMZ]; 1 ♂, Pumahuasi, 20 km north of Tingo María {8°46'48'' S, 75°49'48'' W}, 18 December 1939 [ UMMZ]; 2 ♂♂, 1 ♀, Shapajilla [now Chapajilla] north of Tingo María and NE of Naranjillo, jungle {9°14'0'' S, 75°58'0'' W, 760 m}, 9 May 1939 [ UMMZ]; 1 ♂, 1 ♀, same data but, 11 May 1939 [ CSCA]; 1 ♂, 1 ♀, same data but, 630 m, 14 May 1939 [ RWG]; 1 ♂, same data but [ UMMZ]; 1 ♀, same data but 26 May 1939 [ UMMZ]; 1 ♂, vicinity of Tingo María {8°58' S, 75°50' W, 440 m}, 4 July 1937 [ RWG]; 1 ♂, same data but [ UMMZ]; 1 ♂, same data but 5 July 1937 [ CSCA] ; Junín Reg.: 1 ♂, Satipo {11°16'0'' S, 74°41'0'' W, 714 m}, 10 May 1940, Pedro Paprzycki leg. [ UMMZ]; 1 ♂, same data but 13 May 1940 [ RWG]; 1 ♀, same data but 16 May 1940 [ RWG]; 1 ♂, same data but 28 May 1940 [ CSCA]; 2 ♂♂, 1 ♀, same data but [ RWG]; 2 ♂♂, same data but [ UMMZ]; 1 ♂, 1 ♀, same data but 29 May 1940 [ UMMZ]; 1 ♂, 1 ♀, same data but 1 June 1940 [ UMMZ]; 1 ♂, 1 ♀, same data but 26 June 1940 [ RWG]; 1 ♂, same data but 4 June 1941 [ CSCA]; 1 ♂, same data but [ RWG]; 1 ♂, 1 ♀, same data but [ UMMZ]; 1 ♂, same data but 5 June 1941 [ UMMZ]; 1 ♂, same data but 6 June 1941 [ CSCA]; 2 ♂♂, same data but [ UMMZ]; 1 ♂, same data but 8 June 1941 [ RWG]; 1 ♂, same data but [ UMMZ]; 1 ♀, same data but 9 June 1941 [ CSCA]; 1 ♀, same data but [ RWG]; 3 ♂♂, 1 ♀, same data but [ UMMZ]; 4 ♂♂, 2 ♀♀, same data but 22 June 1941 [ UMMZ]; 1 ♂, 1 ♀, same data but 23 June 1941 [ UMMZ]; 1 ♂, same data but 25 June 1941 [ UMMZ]; 1 ♂, same data but 26 June 1941 [ CSCA]; 1 ♂, same data but [ RWG]; 4 ♂♂, same data but [ UMMZ]; 1 ♀, same data but 9 August 1941 [ UMMZ]; 1 ♂, same data but June 1941 [ RWG]; 1 ♂, same data but 1940 [ UMMZ]; 1 ♂, 1 ♀, same data but June 1941 [ UMMZ] ; Madre de Dios Reg.: 1 ♀, Hotel Amazonia, across from Atalaya (12°52'13'' S, 71°22'34'' W, 414 m), 27 June 1993, Rosser W. Garrison leg. [ RWG]; 2 ♂♂, 4 ♀♀, Manu National Park , Pakitza, stream 0.6 trail km east on Trocha Uno JAL88-008 (12°7'0'' S, 70°58'0'' W, 250 m), 12 September 1988, Jerry Louton leg. [ USNM]; 1 ♀, same data but, stream 0.6 trail km east on Trocha Uno JAL88- 008, 12 September 1988, REARED, emerged 23 September 1988 [ USNM]; 1 ♀, same data but stream 0.7 trail km east on Trocha Uno JAL88-014 19 September 1988, Jerry Louton & F. Chavez leg. [ USNM]; 1 ♂, 1 ♀ # (in copula), same data but stream 0.7 trail km east on Trocha Uno JAL88-014, 19 September 1988 [ USNM]; 2 ♂♂, same data but T2 to R2 to T1 JAL89-020 18 September 1989, Jerry Louton leg. [ USNM]; 1 ♂, same data but T2 basecamp to S85 JAL89-012, 10 September 1989 [ USNM]; 1 ♂, same data but T2 S19 JAL89-009, 8 September 1989 [ USNM]; 2 ♂♂, 1 ♀, same data but Trail 2, 11°55'48'' S, 71°15'18'' W, 17 September 1988, Oliver S. Flint, Jr. leg. [ USNM]; 1 ♂, same data but 20 September 1988 [ USNM]; 1 ♀, same data but 22 September 1988 [ USNM]; 1 ♀, same data but 16 September 1989, Robert Robbins leg. [ USNM]; 1 ♀, same data but Trail 2, marker 12 (log bridge), Nancy E. Adams leg. [ USNM]; 3 ♂♂, 1 ♀, same data but Trail 2, marker 18, seeps [ USNM]; 2 ♂♂, same data but Trail 2, marker 18, seeps, 17 September 1989 [ USNM]; 3 ♂♂, same data but Trail 2, marker 18, seeps, 16 September 1989 [ RWG]; 1 ♂, 1 ♀ (in copula), same data but Trail 2, marker 18, seeps, 12 September 1989 [ USNM]; 3 ♂♂, same data but stream 0.6 trail km east on Trocha 1, 12 September 1988, Jerry A. Louton leg. [ RWG]; 2 ♂♂, same data but Trail 1, marker 14 (1st stream), 9 September 1989, Nancy E. Adams leg. [ USNM]; 1 ♂, same data but Trail 1, marker 33 (2nd stream) [ RWG]; 1 ♂, 1 ♀ (in copula), same data but Trail 1, marker 33 (2nd stream) [ USNM]; 1 ♂, same data but Trail 2, marker 12 (log bridge), September 1989, Donald Harvey leg. [ USNM]; 2 ♂♂, same data but Trail 2, marker 15 (1st stream) 18 September 1989, Nancy E. Adams leg. [ USNM]; 2 ♂♂, 2 ♀♀ (in copula), same data but 23 September 1988, Nancy E. Adams leg. [ USNM]; 1 ♂, 1 ♀, same data but [ USNM]; 1 ♀, same data but, small quebrada near forest zone 1, JAL87-001, 28 September 1987; specimen reared: emerged 15 October 1987 J.A. Louton leg. [ USNM]; 1 ♂, same data but, small quebrada near forest zone 1, JAL87-005, 6 October 1987 [ RWG]; 1 ♂, 1 ♀ (in copula), same data but, small quebrada near forest zone 1, JAL87-005, 6 October 1987 [ RWG]; 1 ♂, 1 ♀ (in copula), same data but, small quebrada near forest zone 1, JAL87-005, 6 October 1987 [ USNM]; 2 ♂♂, 1 ♀, same data but, small quebrada near forest zone 1, 6 October 1987, JAL87-005 [ USNM]; 2 ♂♂, same data but trail 1, 12 September 1988, O.S. Flint, Jr. [ RWG]; 1 ♂, same data but 23 September 1988, N.E. Adams leg. [ RWG]; 1 ♂, same data but trail 1, 12 September 1988, O.S. Flint, Jr. leg. [ USNM]; 1 ♂, 1 ♀ (in copula), Pakitza, trail 1, 9 September 1988 [ RWG]; 2 ♂♂, 2 ♀♀ (in copula), same data but trail 1, 21 September 1988 [ RWG]; 2 ♂♂, 2 ♀♀ (in copula), same data but trail 1, 12 September 1988 [ USNM]; 1 ♂, 1 ♀, Pakitza, trail 1. markers 1 – 13 (11°56'39'' S, 71°16'59'' W, 350 m), 2–6 July 1993, R. Blahnik leg. [ RWG]; 2 ♂♂, 2 ♀♀, same data but Trocha Castanal, stream crossing past plot 3; JAL87-017 (11°55'48'' S, 71°15'18'' W, 250 m), 29 October 1987, Jerry A. Louton leg. [ USNM]; 7 ♂♂, 4 ♀♀, same data but Trocha Castanal, stream near Zone 3, 6 July 1993, Rosser W. Garrison leg. [ RWG]; 2 ♂♂, same data but Trocha Castanal, stream near Zone 3, JAL87-013, 26 October 1987, Jerry A. Louton leg. [ RWG]; 2 ♂♂, same data but Trocha Castanal, stream near Zone 3, JAL87-013 [ USNM]; 4 ♀♀, same data but [ USNM]; 2 ♂♂, 1 ♀, Tambopata-Candamo Reserved Zone, Camp 2, the Plateau, Tambopata River , north bank (13°21'46'' S, 69°33'59'' W), 27 August 1992, Martin Butt [ RWG]; 1 ♂, Tambopata-Candamo Reserved Zone, Camp 3, the Collpa, Tambopata River west bank, stream (13°8'31'' S, 69°36'46'' W), 18 September 1992 [ RWG]; 1 ♂, Tambopata, Trocha B, large flowing stream with cobble substrate (13°8'24'' S, 69°37'17'' W, 256 m), 29 June 2008, Christopher Beatty leg. [ RWG]; 5 ♂♂, 4 ♀♀, same data but 30 June 2008 [ RWG] . Ucayali Reg.: 1 ♂, 1 ♀, Boquerón del Padre Abad , NE of Tingo María {9°4' S, 75°41' W, 440 m}, 8 August 1946, Felix Woytkowski leg. [ CSCA]; 1 ♂, 1 ♀, same data but [ RWG]; 1 ♂, 2 ♀♀, same data but [ UMMZ]; 5 ♂♂, 2 ♀♀, same data but 9 August 1946 [ UMMZ]; 1 ♂, 1 ♀, same data but 10 August 1946 [ CSCA]; 1 ♂, 1 ♀, same data but [ RWG]; 2 ♂♂, same data but [ UMMZ]; 2 ♂♂, 1 ♀, same data but 11 August 1946 [ UMMZ]; 1 ♂, 1 ♀, same data but 12 August 1946 [ RWG]; 2 ♂♂, 2 ♀♀, same data but 24 August 1946 [ RWG] . BOLIVIA, Beni Dept.: 1 ♂, Rurrenabaque {14°28'0'' S, 67°34'0'' W, 299 m}, 10–23 October 1923, L. Peña leg. [ RWG] ; Cochabamba Dept.: 1 ♂, San Mateo bajo, San Mateo , catalog # 0B-0005, {17°0'16'' S, 65°25'42'' W, 380 m}, 9 December 1981, J.C. Lien leg. [ FSCA]; 2 ♂♂, small river 27.1 km east of Chapare River , highway (4, 17°0'2'' S, 65°11'40'' W, 257 m), 14 November 2001, Jerrell J. Daigle leg. [ JJD] ; Santa Cruz Dept.: 1 ♂, Bermejo, Refugio Los Volcanes , small river from camp to main river (18°6'18'' S, 63°35'54'' W, 1,080 m), 2 – 24, Caroli Hamel & Darren Mann leg. [ OUMNH]; 1 ♂, near Buena Vista {18°36'0'' S, 59°20'0'' W, 225 m}, 8 May 1960, Roy Steinbach leg. [ FSCA] .

A red-eyed species with a brilliant cupreous thoracic dorsum and with dorsum of S1–7 largely black, with pattern similar to that observed in Argia dives Förster.

Description of male holotype. Head ( Fig. 20 ): Entire face with metallic cupreous-red reflections except for the following: narrow apical margin of labrum, anteclypeus, base of mandibles and genae dark orange, small postocular spots blue, small pale spot anterolateral to lateral ocellus; antennae black; rear of head including margin black except for narrow pale border along eye margin (as in Fig. 5 ).

Prothorax entirely metallic cupreous-red except for blue anterior lobe. Mesothorax with mesepisternum brilliant cupreous-red, mesepimeron and mesinfraepisternum metallic dark purple; metepisternum and metepimeron blue interrupted by dark stripe along metapleural suture ( Fig. 20 ). Wings slightly smoky with venation black; pterostigma trapezoidal, dark brown, surmounting 1 cell in all wings; postnodals Fw 16/15, Hw 14/ 13; postquadrangular cells Fw 5/5, Hw 4/4; RP2 at Fw 8/7, Hw 6/6. Coxae and trochanters pale brown anteriorly becoming darker posteriorly; femora, tarsi and armature black, tibiae black, pale externally.

Abdomen ( Figs. 20 , 55) mostly black; S1 black at basal 0.40 dorsally, narrowing to basal 0.20 laterally, remainder blue; S2 black dorsally, blue laterally with a narrow brown stripe below with pointed extensions meeting black dorsally at basal 0.20 and 0.50, thus isolating pale blue spot laterally followed by black along ventral margin of tergite, annulus black; S3 black with a narrow blue basal ring connecting below with a narrow pale lateral stripe extending to apical 0.20; S4–7 similar to S3 but pale lateral stripe reduced on S4, vestigial on S5 and absent on S6– 7; S8 black except for dorsolateral blue spot on basal 0.60; S9–10 blue dorsally black laterally; torus pale, appendages black.

Genital ligula (as in Fig. 100 ) with a pair of small laterally extended lobes at base near flexure (these hidden by membranous terminal fold) followed by a pair of flexible chitinized branches, each arising from a narrow stem at distal segment base extending laterad of the ligula; distal portion with narrow parallel digit-like hood surmounting over coiled digit-like paired flagella, the latter not fused basally but jointing a prominent entally directed pyramidlike lobe at base.

Torus small, transversely oval, occupying entire ventral margin of torifer and not overlapping bilobed epiproct ( Fig. 119b ); base of epiproct and area around base black, apical portion of epiproct pale; cercus ( Fig. 119 ) robust, longer than wide, about subequal to paraproct, slightly convex dorsally, branched apically with distal margin of shorter outer branch ending at approximate right angle to longer slightly decumbent inner branch; in dorsal view ( Fig. 119b ), medial margin slightly convex basally, slightly concave distally; cercus ventrally concave; paraproct bilobed, its ventral branch narrow, bluntly pointed, its base at about 120° from acutely pointed anteriorly directed dorsal branch.

Dimensions. Hw 22.6, abdomen 30.0, total length 38.7.

Description of female paratype ( Peru: Madre de Dios Reg., Pakitza, Trocha Castañal, stream near Zone 3). Head ( Fig. 31 ): labrum with distal half ochre (as in Fig. 6 ), basal half metallic cupreous-red; anteclypeus ochre divided medially by dark line connecting postfrons with postclypeus; postclypeus metallic cupreous; antefrons, genae and base of mandibles pale ochre; postfrons and remainder of epicranium metallic cupreous; a pair of pale small spots anterolateral to lateral ocelli and postocular spots blue; rear of head black except for narrow pale border along eye margin (as in Fig. 5 ).

Prothorax metallic cupreous, anterior lobe pale blue, lateral 0.20 of posterior margin of hind lobe and propleuron pale ochre; synthoracic dorsum ( Fig. 31 ) black with cupreous reflections and with a pale ochre antehumeral stripe widening slightly ventrally; entire metepimeron metallic cupreous, divided at upper 0.10 with branches enclosing an irregular elongate pale ochre spot, mesinfraepisternum with anterior 0.70 black, remainder ochre; metathorax ochre except for narrow black stripe at metapleural suture; venter of thorax ochre; S1 pale olive with basal ring of black and with narrow posterior black ring; S2 largely black with cupreous metallic reflections with narrow pale middorsal line briefly constricted at apical 0.20 before widening but ending at black apical annulus (as in Fig. 66), laterally pale with a narrow brown stripe and followed below by a narrower pale longitudinal stripe bordering ventral margin, annulus black; S3–7 similar but pale middorsal stripe a mere line (similar to Fig. 65); S8 like S7 but pale lateral stripe expanding posteriorly, posterior portion of sternum pale; S9 similar to S8 but with dorsal black divided middorsally forming a pair of lobes ending at apical 0.60 and with pale blue area connecting with pale lateral stripe, S10 largely pale blue; cerci black, ovipositor pale except for black ventral margin (Fig. 65).

Mesostigmal lobe ( Fig. 82 ) erect, forming a prominent upright lobe occupying medial 0.40 of slightly raised plate, medial margin of lobe well separated from branching middorsal carina by a low carina extending from medial base of lobe, medial margin of lobe not recurved in mediolateral view ( Fig. 82e, b ); mesostigmal lobe accompanied by a well-developed mesepisternal tubercle posterodistal to outer margin of erect lobe ( Fig. 82a ).

Variation in paratypes. Both sexes vary but little. Extent and degree of metallic coloration on the thorax is tempered by age; older females tend to be less metallic. Pterostigma surmounting 1–2 cells in males and females; postnodals: Fw 15–18, Hw 13–15 in males, Fw 14–17, Hw 12–15 in females; postquadrangular cells Fw 4–5, Hw 3–5 in males, Fw 4–5, Hw 4 in females; RP2 at Fw 7–8, Hw 6–7 in males, Fw 6–8, Hw 6–7 in females. Dimensions. ♂: Hw 20.3 ± 1.1 [18.3–22.6], abdomen 28.4 ± 1.1 [27.5–30.5], total length 36.3 ± 1.5 [34.2–39.2]. ♀: Hw 21.7 ± 0.8 [20.7–23.5], abdomen 26.9 ± 0.9 [26.1–29], total length 34.8 ± 1.2 [33.6–37.3].

Diagnosis. Argia philipi belongs to a characteristic group of species possessing an entirely metallic cupreous thoracic dorsum. Of the eight species in this group known from South America five, A. dives , A. fulgida , A. jocosa , A. limitata and A. philipi , have been recorded from Ecuador. Males of all in life have the dorsal half of the compound eyes red, a conspicious field character, although postmortem preservation may preclude their practical use as a diagnostic character. Although the metallic mesepisterna are diagnostic, the cupreous condition becomes dulled in old males and the luster tends to dull considerably in males that have undergone acetone treatment. In this group as a whole, the metallic mesepisterna ranges from a bright copper to a dull intense metallic purple condition and contrasts against the remainder of the synthorax which is pale blue or purple. The entire mesepisternum is usually metallic (as in Fig. 20 ) but in some males (e.g. A. fulgida , Figs. 14, 16 ; A. jocosa , Fig. 17 ), it may be limited to the medial half with the lateral 0.50 blue, although this appears to be rare.

One characteristic feature uniting this group is the presence on the genital ligula of a pair of chitinized branches each arising from a narrow stem at the base of the terminal segment however, this structure is also present in the dark-eyed Argia insipida Hagen in Selys species group including A. barretti Calvert , A. harknessi Calvert , and A. pipila Calvert (the latter three are not known from South America). Each branch arches dorsally (ectally), and becomes broader at tip where its outer margin is armed with small digit-like branches ( Figs. 93–97b , 99b, 100b ). These branches, which are best seen in dorsal (ectal) view, are flexible and extend laterally to dorsolaterally depending on preservation. We have not found the armature of these structures to be species specific.

Females of the metallic red group also have a degree of metallic thoracic coloration but this is confined to the medial half of the mesepisternum (as in Figs. 25, 26 , 31 ). Females of this group can usually be identified, in addition to their metallic thoracic coloration, by the presence of a pair of tuberculate processes or swellings mediolaterally along the hind lobe of the prothorax which gives a trilobate appearance to the hind margin (an apparent apomorphy for the group). Mesostigmal lobes are strongly developed, erect and are usually accompanied by a mesepisternal tubercle ( Fig. 73e, 74d , 77b, 82 b ; poorly developed to absent in A. cupraurea and A. fulgida , Fig. 75g ) just posterior to the border of each mesostigmal plate.

Figures

FIGURES 1–8. Color pattern of head. Head, anterior view (1); head posterior view (2–5); labrum, anterior view (6–8).

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

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

FIGURES 119–122. Male caudal appendages. (a) lateral view; (b) dorsal view; (c) mediodorsal view; (d) ventral 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 77–83. Female mesostigmal plates. (a) dorsal view; (b) laterodorsal view; (c) lateral view; (d) detail of mesostigmal lobe, dorsal view; (e) detail of mesostigmal lobe, medial view; (f) frontal (anterior) view; (g) detail of mesostigmal lobe, posterior view; (h) posterior view.

FIGURES 14–18. Color pattern of male head, thorax, and S1–4. Head, dorsal view, thorax and S1–4, lateral view.

FIGURES 89–93. Genital ligula. (a) lateral view; (b) ectal view; (c) entolateral view.

FIGURES 94–97. Genital ligula. (a) lateral view; (b) ectal view; (c) entolateral view.

FIGURES 23–27. Color pattern of female. Head, thorax, and S1–4 (23, 24, 26, 27); pterothorax (25). Head, dorsal view, thorax and S1–4, lateral view.

FIGURES 73–76. Female mesostigmal plates. (a) dorsal view; (b) detail of mesostigmal lobe, dorsal view; (c) frontal (anterior) view; (d) detail of mesostigmal lobe, anteromedial view; (e) laterodorsal view; (f) detail of mesostigmal lobe, anterior view; (g) detail of mesostigmal lobe, posterior view; (h) posterior view.