Heteragrion triangulare Hagen

LENCIONI, F. A. A., 2013, <p> <strong> Diagnoses and discussion of the group 1 and 2 Brazilian species of <em> Heteragrion </ em>, with descriptions of four new species (Odonata: Megapodagrionidae) </ strong> </ p>, Zootaxa 3685 (1), pp. 1-80 : 14

Heteragrion triangulare Hagen in Selys, 1862

Figs. 25 (♂ app), 34D–F (♂ thx), 35 (♂ thx), 40D–G (♀ thx), 41 (♀ thx), 47G–H (♀ S8–10, basal plate), 55 (♂, ♀ habitus), 65 (♂ live photo), 75 (map)

Heteragrion triangulare Hagen in Selys 1862: 22–23 [20–21 reprint] (female description); Selys 1886: 58–59 (description of male and female but not sure they are conspecific); Calvert 1909: 112–114, Fig. 39 (description of male and female, illustration of male appendages in mediodorsal view); Williamson 1919: 22–23, Figs. 17–18, 112, 137–138 (discussion on species, authorship and Selys' 1886 descriptions, illustrations of male and female head and prothorax in dorsal view, male appendages from Calvert 1909); St. Quentin 1970: 259 (erroneously designates Vienna female as lectotype instead of holotype); Lencioni 2005: 142, Fig. 89A (data on description and distribution, illustration from Calvert, 1909); Machado, 2006: 1068–1069 (differences from H. mantiqueirae and H. dorsale ); Garrison et al 2010: 88 (list).

Heteragrion beschkii: Lencioni 2005: 128 (misidentification)

Types. Female holotype in NHMV. Data on labels: Red paper printed with black letters " Paratypus ", [Para— crossed out], word "Holo" and "St. Quentin 1967" in St. Quentin’s handwriting; white paper with " triangulare " in handwriting "det. Brauer " printed [Brauer label]; greenish paper in black handwriting "Shtt." [= Heinrich Wilhelm Schott, who collected in St. Catarina, Brazil, 1817–1821 during the Leopoldina Expedition ]; white paper in black handwriting "7" [probably Hagen’s numbering]; yellowish paper in black handwriting " Hagen determ." .

Specimens examined. 4♂ 3♀. Brazil: Goiás State: Barro Alto, 15°05'18"S, 48°58'26"W, 20-V-2009 , 1♂ 1♀ (copula), leg. S. L. Dutra, N. S. Pinto, C. C. Nóbrega & E. Santos; Rio de Janeiro State: Cachoeira de Macacu , 22°26'9.5"S, 42°45'32.4"W, 25-IV-2012 , 1♂, leg. T. Kompier ( FAAL); Mato Grosso State: Chapada dos Guimarães, XI-1963 , 1♂ 2♀, leg. Werner & Alvarenga ( ABMM); Paraná State: Cascavel , 25º16'03.18"S, 53º21'52.76"W, 06-I-2011 , 1♂, leg. M. E. Rodrigues ( FAAL) .

Illustration made from following specimens. 1♂ ( Fig. 25A, 25B, 34D, 34E, 34F, 55A) and 1♀ ( Fig. 40E, 40F , 47G, 47H , 55B )— Brazil: Goiás State: Barro Alto , leg. S. L. Dutra, N. S. Pinto, C. C. Nóbrega & E. Santos ( NC 4625 ) ; additional color for comparison: 1♂ (Fig. 35A, 35B)— Brazil: Rio de Janeiro State: Cachoeira de Macacu , 25-IV-2012, leg. T. Kompier ( FAAL) ; 1♂ ( Fig. 35C, 35D) and 2♀ ( Fig. 40G , 41C, 41D, 41E, 41F)— Brazil: Mato Grosso State: Chapada dos Guimarães , XI-1963, leg. Werner & Alvarenga ( ABMM) ; 1 ♂ (Fig. 35E, 35F)— Brazil: Paraná State: Cascavel , 06-I-2011 , 1 ♂, leg. M. E. Rodrigues ( FAAL) ; photos of the female holotype ( Fig. 41A, 41B) .

Distribution. Brazil (states of Goiás, Mato Grosso, Santa Catarina, Paraná, Rio de Janeiro). Argentina.

Diagnosis. Male: Easy to identify: shares with H. ictericum presence of a ventro-basal apophysis (less perpendicular in H. triangulare than in H. ictericum ). Cercus in lateral view: dorsobasal expansion present. Ventrobasal expansion small, occupying less than 1/3 length. Almost straight (Fig. 25B). Cercus in mediodorsal view: basal, medial and apical portions subequal. Very small ventral expansion heavily hairy. Medial process wide, triangular plate with step on external side, wider slightly S-curved sclerotized ridge reaching external side (Fig. 25A). Female: Posterior lobe of prothorax with long lateral projections, most of lobe taken up by rounded and projected central area which is pale with rounded black spot in central region (shape shared with H. ictericum — Fig. 40F–G , 41B, 41D, 41F, 46D). Valves of ovipositor surpassing distal S10, ventral margin with long spines; cercus longer than S10, with tuft of bristles at tip; Basal plate: dorsal edge concave, longer than convex outer edge. Ventral side 2/3 length of outer edge ( Fig.47H ).

Remarks. This species possesses remarkable color variation, with the widest range of all analyzed species. In both males and females, it varies from yellowish in young/not sexually mature individuals (male—Fig. 35A–F; female— Fig. 40G , 41A–F) to almost black in fully mature individuals (male Fig. 34D–F; female Fig. 40D–F ).

Figures

FIGURE 39. Heteragrion rogertaylori (male holotype) (A) thorax in lateral view, (B) thorax in dorsal view, (C) prothorax in dorsal view; Heteragrion johndeaconi (male holotype) (D) prothorax in dorsal view, (E) thorax in lateral view, (F) thorax in dorsal view.

FIGURE 40. Heteragrion dorsale male: (A) thorax in lateral view, (B) thorax in dorsal view, (C) prothorax in dorsal view;

FIGURE 47. Female: Heteragrion aurantiacum (A) S8–S10, (B) basal plate; Heteragrion consors (C) S8–S10, (D) basal plate; Heteragrion luizfelipei (paratype) (E) S8–S10, (F) basal plate; Heteragrion triangulare (G) S8–S10, (H) female basal plate.

FIGURE 55. Heteragrion triangulare (A) male, (B) female. Scale bar = 10 mm.