Heteragrion palmichale Hartung, 2002

Vilela, Diogo Silva, Lencioni, Frederico A. A., Bota-Sierra, Cornelio A., Ware, Jessica L. & Bispo, Pitágoras C., 2023, Taxonomic revision of the Neotropical genus Heteragrion Selys, 1862 (Zygoptera: Heteragrionidae): male morphology, new species and illustrated key, Zootaxa 5356 (1), pp. 1-96 : 74

Heteragrion palmichale Hartung, 2002

( Figs. 53a–c )

[Key locator: Key to Group B species, couplet 4 (2)]

Heteragrion palmichale: Hartung 2002: 187–191 (description and diagnosis of ♁ from Venezuela; compared in size with H. tricellulare , morphologically with H. simulatum , H. peregrinum and H. icterops ; figs. 1–9);— De Marmels 2004: 443 (recorded in Porto Cabello, Venezuela);— De Marmels 2008: 151–155 (comparisons with H. archon );— Garrison et al. 2010: 88 (list of Heteragrion species);— Vivas-Santeliz & De Marmels 2017: 50 (species endemic to Venezuela).

Material examined. Known only from type material; examined through original description and holotype images (holotype housed at MIZA).

Known distribution. Northern Venezuela.

Diagnosis and remarks. Heteragrion palmichale is an enigmatic species, described from two males collected at “Via Palmichal”, a road area near Cerro de Paja mountain (Carabobo, Venezuela), in 1992 ( Hartung 2002). According to Hartung (2002), the main characteristics of this species, setting it apart from the remaining Heteragrion species were: the large size (abdomen 52.5mm), the large paraptocts (referred by him as “spine-like inferior appendages”), and the “strongly arched” (curved downwards at its midlength) cercus ( Fig. 53c ). De Marmels (2008) described H. archon , which shares several morphological similarities with H. palmichale , such as (in parenthesis the nomenclature used in this study): “cercus arched downwards, expanding towards tip”, “paraproct long and robust”, “total body size unusually large”, “tip apparently trifid, due to shortening of terminal branch” (AP referred to as the terminal branch, forming a trifid branch with ML), and “apical excision of internal branch as to suggest presence of a third, median branch” (ML with a medial excision, that is, bilobate). In contrast, De Marmels also pointed out the characters separating the two species: H. archon having larger body size, including wings; head color pattern, and the arching of cercus in lateral view, which is more angled in H. palmichale ( Fig. 53c ) than in H. archon ( Fig. 11c ). Regarding its conservation status, H. palmichale was recently assessed in the IUCN Red List as Critically Endangered (CR), and possibly extinct, “as it has not been seen since its initial discovery in 1992” and “no conservation actions are protecting it and it is threatened by urban and agriculture expansion, natural fires and water extraction for crop irrigation” ( Vivas-Santeliz et al. 2021b).

Figures

FIGURE 11. Heteragrion archon: (a) anterior view of head; (b) lateral view of pterothorax; (c) lateral view of anal appendages; (d) mediodorsal view of anal appendages; (a–b) adapted from the original drawings by De Marmels (2008). Figures c–d provided by Rosser Garrison and Natalia von Ellenrieder.

FIGURE 53. Heteragrion palmichale: (a) anterior view of head; (b) lateral view of pterothorax; (c) lateral view of anal appendages; (a–b) adapted from Hartung (2002).