Heteragrion calendulum Williamson, 1919

Bota-Sierra, Cornelio Andrés & Novelo-Gutiérrez, Rodolfo, 2017, The genus Heteragrion (Odonata: Zygoptera) in Northwestern Colombia, with the description of Heteragrion tatama sp. nov., Zootaxa 4347 (3), pp. 553-571 : 559-562

Heteragrion calendulum Williamson, 1919

Heteragrion atrolineatum Donnelly, 1992 . (Holotype ♂, Allotype ♀ in USNM). Syn. nov.

Material Examined. COLOMBIA: 1♂ Holotype, Department of Antioquia, Municipality of Puerto Berrio, La Cristalina Township , 17 February 1917, J.H. and E.B. Williamson . 1♂ and 1♀: Department Risaralda, Municipality of Pueblo Rico, Santa Cecilia Township, Alto Amurrupá Reserve , Ranas de Cristal stream, 5.32033°N 76.17357°W 620m a.s.l., 15 February 2017, J. Sandoval and C. Bota leg . 6♂♂ and 2 ♀♀: PANAMA, Darién, Perresénico River, Estación Rancho Frío , 8.01982°N 77.73257°W 80m a.s.l., 17 November 2014, D. Delgado, A. Ramírez and R. Novelo leg.

Remarks. This species was described based on a single male collected at La Cristalina stream (Puerto Berrio- Antioquia) on February 17 of 1917, by Jesse Williamson and Edward B. Williamson, who were impressed by its beauty and rarity and tried, unsuccessfully, to catch some more specimens ( Williamson 1919). Exactly one century after this first collection, a second collection was made on February 15 of 2017 at the Ranas de Cristal stream (Santa Cecilia-Risaralda) by Juliana Sandoval and Cornelio Bota-Sierra who, as the Williamsons tried in vain to get more specimens, luckily caught a pair in tandem. The male specimen matched Williamson’s description exactly ( Figs 3i, k ; 4b; 6a, i–j). Examination of female genital valves showed several rows of denticles ( Fig. 9d ) which places it in Lencioni´s group A. Williamson (1919) classified this species within the group B based on the small elongated finger-like paraprocts of male ( Fig. 6j ), which make this species an intermediate between groups A and B. Further analysis will be needed to determine the monophyly of these groups and where to place H. calendulum .

Specimens deposited in IEXA, collected in Panama and formerly identified as H. atrolineatum using Donnelly´s (1992) taxonomic key and diagnosis, were reexamined and compared to Williamson´s description of H. calendulum , as well as to the Colombian specimens. Also, Dr. Garrison compared the paratypes of H. atrolineatum in his collection to our pictures and description of the new Colombian specimens. After a thorough examination of these specimens, we conclude that H. atrolineatum is a junior synonym of H. calendulum ( Figs 3i –k ; 4 b–c, h–i; 5b; 6a–b, i–j; 8d). Donnelly (1992) followed Williamson’s (1919) criteria grouping H. atrolineatum with H. chrysops , H. alienum and H. tricellulare because of their pale coloration on dorsum of abdominal segments. Donnelly (1992) recognized a variation in color pattern with the Panamanian males having slightly darker color than Costa Rican males. Mark O´Brien, collection manager of the University of Michigan, Museum of Zoology, photographed the holotype of H. calendulum and Dr. Garrison photographed a Costa Rican paratype of H. atrolineatum , based on this evidence we concluded that the only difference between these specimens is the darker coloration pattern on the holotype of H. calendulum , which probably led Donnelly to confuse them using Williamson´s key. Therefore, we consider that H. atrolineatum is a junior subjective synonym of H. calendulum .

Bota-Sierra et al. (2016) erroneously recorded a second locality for H. calendulum in Amalfí-Antioquia. They were led astray by the similar coloration pattern of the face of H. aequatoriale with that of H. calendulum ( Fig. 3g, i ). After the rediscovery of H. calendulum and the comparison with diverse populations of H. aequatoriale , it becomes clear that the Amalfí population is a morph of H. aequatoriale , with a variation in face coloration close to H. calendulum .

Figures

FIGURE 3. Face color pattern. H. aequatoriale, males: a, Cordillera Central, Santo Domingo; b, Cordillera Occidental, Jericó; c, Cordillera Occidental, Anchicayá; d, Cordillera Central, Carmen de Viboral; e, Cordillera Occidental, PNN Tatamá; f, Cordillera Central, San Luis; g, Cordillera Central, Amalfí; h, female, Cordillera Occidental, PNN Tatamá. H. calendulum: i, male, Santa Cecilia; j, female, Santa Cecilia; k, male Holotype (UMMZ), La Cristalina. H. peregrinum: l, female Paratype (RWG), La Cristalina. H. m. atroterminatum: m, male, Anchicayá; n, female, Santa Cecilia. H. tatama: o, male, PNN Tatamá; p, female, PNN Tatamá. Picture k, by Dr. O´Brien and l, by Dr. Garrison.

FIGURE 6. Heteragrion calendulum, Santa Cecilia, habitus: a, male; b, female (Photos by Juliana Sandoval). H. aequatoriale, PNN Tatamá, male caudal appendages: c, middorsal view; d, dorsal view. H. tatama, PNN Tatamá, male caudal appendages: e, middorsal view; f, dorsal view; g, lateral view; h, middorsal view (different view angle compared with figure 6 e). H. calendulum, male cercus in middorsal view: i, Rancho Frío (Panama); j, Holotype, La Cristalina (Colombia). Da. r.: Dorsoapical ridge; M. p.: Medial process; M. r.: Medial ridge; Vb. e.: Ventrobasal expansion. Illustrations c-g by Natalia Uribe, j by Edward Williamson.

FIGURE 9. Heteragrion tatama, PNN Tatamá: a, male; b, female. Female venter of S 9 - S 10: c, H. aequatoriale, PNN Tatamá; d, H. calendulum, Santa Cecilia; e, H. m. atroterminatum, Santa Cecilia; f, H. tatama, PNN Tatamá.