Heteragrion silvarum Sj, 1918

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 : 81-83

Heteragrion silvarum Sj ̂stedt, 1918

( Figs. 60a–g )

[Key locator: Key to Group A species, couplet 8 (7)] Heteragrion silvarum:Sjöstedt1918:4–6 (description of♁ and ♀;comparison with H.aurantiacum , H.cinnamomeum and “ H. malicentum ” [misspelled]; plate 1, fig. 10);— Williamson 1919: 63–64 (discussion and comparison with other species);— De Marmels 1987: 229–231 (redescription of holotype and ♀ paratype, differences from H. ictericum , illustration of ♁ and ♀ head and prothorax, ♁ thorax, ♀ S 8–10 in lateral view, ♀ S 9–10 in ventral view; figs. 13–19, 47–48);— Lencioni 2005: 141 (data on description and distribution, illustration from Sĵstedt 1918 and De Marmels 1987; figs. 88a–j);— Garrison et al. 2010: 88 (list of Heteragrion species);— von Ellenrieder 2012: 59, 62, 73 (list of species from Suriname; mentions synonymy with H. melanurum );— Lencioni 2013: 13 (synonymic list, types, distribution, diagnosis, remarks; figs. 23, 33d–f, 54c, 72);— von Ellenrieder et al. 2017: 3 (list of species from Guyana);— Rochas et al. 2022: 200 (species recorded from French Guiana).

Heteragrion melanurum: Williamson 1919: 20–22 (key to species, ♁ in couplet c2; description of ♁; comparison with H. ictericum ; figs. 9, 16, 76–77, 136);— Paulson 1981: 303 (comparison of coloration patterns with other Heteragrion species);— De Marmels 1987: 229–231 (proposed synonymy with H. silvarum ).

Material examined. 1♁ BRAZIL, Pará state, Flona de Carajás, Igarapé Afluente do Rio Águas Claras , 22.viii.2022, (-5.9881, -50.4984, 240m asl), G. Desidério leg., INPA; 1♁ Tailândia, Agropalma, 7.iv.2012, J.M. B. Oliveira-Jr. leg., LABECO; 5♁♁ Tailândia, Agropalma (H48H50), 25.x.2016, (-2.6183, -48.8301), Vilela , Cordero-Rivera , Amorim & Rivas-Torres leg., LESTES; 4♁♁ same data, but (P1F1), 27.x.2016, (-2.6191, -48.7811); 3♁♁ same data, but (P10P2), 3.xi.2016, (-2.3116, -48.6692); 1♁ same data, but (P21P13 Novo), 4.xi.2016, (-2.2663, -48.6268); 1♁ same data, but (P24P14), 23.x.2016; (-2.5737, -48.8174); 1♁ Rondônia state, Porto Velho , 3.v.1922, (-8.7500, -63.9000, 100m asl), J.H. Williamson & J.W. Strohm leg., ABMM; 1♁ same data, but FAAL .

Synonyms. Heteragrion melanurum Williamson, 1919 ( De Marmels 1987)

Known distribution. Brazil (states of Amazonas, Pará and Rondônia).

Diagnosis and remarks. This species shares with H. cooki and H. cinnamomeum the cercus with a long BP, ending in subequal MP and AP, with a developed ML. The following character combination distinguishes this species from the remainder of Group A species: straight BP margin ( Fig. 60d ); ML broad, roughly squared ( Figs. 60d–g ); ML ridge short, nearly straight, reaching or not ML apex ( Fig. 60f ); ML apex blunt, not bilobate; MP–AP junction rounded or angled ( Figs. 60d–g ).

Figures

FIGURE 60. Heteragrion silvarum: (a–b) anterior view of head; (c) lateral view of pterothorax; (d–g) mediodorsal view of cercus. BP: basal portion; MP: medial portion; AP: apical portion.