Heteragrion cinnamomeum Selys, 1862

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 : 38-39

Heteragrion cinnamomeum Selys, 1862

( Figs. 24a–e )

[Key locator: Key to Group A species, couplet 7’]

Heteragrion cinnamomeum: Selys 1862: 26 [24 reprint] (description of ♁ from Bahia state, Brazil as possible race of H. aurantiacum );— Selys 1886: 60 (as synonym of H. aurantiacum );— Williamson 1919: 25–26 (questions authorship of taxon and synonymy with H. aurantiacum ; suggests synonymy with H. ochraceum ; illustration of ♁ appendages in dorsal and lateral views; figs. 123–124);— Santos 1970: 149 (compares with H. consors , stating they are similar in color but easily distinguished by appendages);— Lencioni 2005: 139 (as synonym of H. ochraceum , illustrations from Williamson 1919);— Garrison et al. 2010: 88, 90 (list of Heteragrion species; figs. 379–380);— Lencioni 2013: 7 (synonymic list, information on types, distribution, diagnosis, remarks; figs. 13, 32 e –g);— Lencioni 2017: 135–136 (general taxonomic information; distribution; fig. 62);— Ribeiro et al. 2021: 161–186 (species list from Bahia state).

Heteragrion macilentum: Hagen in Selys 1862: 26–27 [24–25 reprint] (in part) (description of ♁ and ♀ from Brazil);— Selys 1886: 60–61 (misspelled as “ H. macitentum ”, diagnosis from H. aurantiacum );— Williamson 1919: 23 (discussion);—St. Quentin 1970: 259 (lectotype designation);— De Marmels 1990: 335 (species recorded in Venezuela);— De Marmels 2004: 442–443 (discussion of lectotype; illustration of ♁ head, prothorax and appendages; figs. 14–17);— Lencioni 2005: 135 (mention from Brazil; illustrations from De Marmels 2004);— von Ellenrieder & Garrison 2007: 6 (lectotype name synonymized with H. cinnamomeum ; illustration of ♁ appendages in mediodorsal, dorsal, and lateral views; figs. 2j–o).

Material examined. 1♁ BRAZIL, Bahia state, Valença , 9.xii.1986, (-13.3666, -39.0833, 59m asl), Biriba leg., ABMM ; 1♁ (SYNTYPE) Probably Rio de Janeiro, examined through photos, RBINS .

Synonyms. Heteragrion macilentum Hagen in Selys, 1862 ( Williamson 1919; von Ellenrieder & Garrison 2007).

Known distribution. Brazil (Bahia and prob. Rio de Janeiro) and Venezuela.

Diagnosis and remarks. Rare species, known from only a few individuals, including the holotype (housed in RBINS), a male collected in Valença, Bahia state, Brazil (in ABMM) and a small series collected in Reserva Serra Bonita, also in Bahia state (Rosser Garrison pers. comm.). Since it was described in 1862, there has been much confusion with the identity of this species, along with H. aurantiacum and H. ochraceum ( Williamson 1919) . Selys (1862) described H. cinnamomeum as a possible “race” of H. aurantiacum , relying on coloration characters. However, with further information on the types of H. aurantiacum and H. cinnamomeum , we could finally realize that they are in fact two separate species ( von Ellenrieder & Garrison 2007). On the other hand, the confusion of the species with H. ochraceum has not yet been resolved, since the male of material type is lost, and the female specimens of the latter species are damaged. The confusion between the two species is long-standing. For example, in label of one female of H. ochraceum was written by Hagen “ Argia cinnamomea ”, leading to the possibility that the specimens belong to H. cinnamomeum ( Williamson 1919) . Furthermore, in his revision, Williamson (1919) noted that there was evidence in Hagen’s collection that he considered the two names to be synonymous. In fact, despite not formalizing the synonymy, apparently both Hagen and Williamson considered that there was a high probability of H. ochraceum being a senior synonym of H. cinnamomeum . However, according to current knowledge, it is not possible to state that the two species are synonymous of H. ochraceum since the type series of H. ochraceum has lost or damaged specimens. Given this, and with the evidence provided by von Ellenrieder & Garrison (2007), in this study we consider H. cinnamomeum as a valid name. The scarcity of information and the old collection dates of the known specimens make it also difficult to assess the conservation status of this species; therefore, it is classified as Data Deficient in the IUCN Red List ( Vilela & Guillermo-Ferreira 2021d). Regarding its distinction, this species has a similar cercus to that of H. silvarum and H. cooki , characterized by a long BP, ending in MP and AP of approximately the same length, and featuring a well-developed ML. The following character combination distinguishes H. cinnamomeum s from the remainder of Group A species: BP slightly curved inwards ( Fig. 24c ); ML narrow, ridge bearing strong teeth ( Fig. 24e ); ML apex ‘W’ shaped, bilobate ( Figs. 24c–e ).

Figures

FIGURE 24. Heteragrion cinnamomeum: (a) anterior view of head; (b) lateral view of pterothorax; (c–e) mediodorsal view of cercus. BP: basal portion; ML: medial lobe. Figure e provided by Rosser Garrison and Natalia von Ellenrieder.