Heteragrion tricellulare Calvert, 1901

(Figs. 66a–e)

[Key locator: Key to Group B species, couplet 22’] Heteragrion tricellulare: Calvert 1901: XX, 62–63 (key to species, couplet 1; description of ♁ and ♀; comparison with H. aequatoriale; plate V, fig. 5);— Williamson 1919: 33 (key to species, ♁ in couplet c1, ♀ in couplet a1; remarks, comparison with H. albifrons; figs. 34–36, 107, 150–151);— Paulson 1981: 303 (comparison of coloration patterns with other Heteragrion species);— Novelo-Gutiérrez 1987: 11–22 (description of F0 larvae);— Dunkle 1993: 355 (comparison with the ♀ of H. azulum);— Garrison et al. 2010: 88 (list of Heteragrion species);— Escoto-Moreno et al. 2017: 386 (record from Hidalgo state, Mexico);— Carrillo-Muñoz & García-Miranda 2022: 196–203 (species list from Mexico).

Material examined. 2♁♁ MEXICO, Chiapas, Trinitaria Santa Rosa, vi.1969, P. Hubbell leg., ABMM .

Known distribution. Guatemala and Mexico.

Diagnosis and remarks. The following character combination distinguishes this species from the remainder of Group B species: AP the longest cercus portion, slightly longer than BP (Fig. 66e); ridge above ML small, consisting of strong teeth (Figs. 66c–e); ML apex acute (Figs. 66c–e).