Heteragrion ovatum 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 : 71-74

Heteragrion ovatum Selys, 1862

( Figs. 52a–j )

[Key locator: Key to Group A species, couplet 23 (20’)] Heteragrion ovatum: Selys 1862: 19–20 (description of ♁ from Brazil; comparison with H. dorsale );— Selys 1886: 56 (assigns the ♀ as H. ochraceum );— Williamson 1919: 11, 16–17 (key to species, ♁ in couplet b2; remarks);— Machado 1988: 273 (comparison with H. petiense );— Machado & Bedê 2006: 50–51 (comparison with other Heteragrion species);— Garrison et al. 2010: 88 (list of Heteragrion species).

Material examined. Examined through original description and images of supposed representatives of this species. 1♁ BRAZIL, São Paulo state, Campos do Jordão , i.1966, (-22.7458, -45.5797, 1700m asl), Ebert leg., RWG ; 1♁ Rio de Janeiro state, Parque Nacional do Itatiaia , 11.i.1973, (-22.4166, -44.6166, 1300m asl), O.H.H. Mielke leg., RWG .

Known distribution. Brazil (states of São Paulo and Rio de Janeiro).

Diagnosis and remarks. It should be noted that the specimens discussed in this study may only represent potential examples of the elusive H. ovatum , although they closely resemble the description and the small illustration provided by Selys ( Figs. 52i–j ). See the original description below (translated from French by Rosser Garrison):

“Abdomen ♁: 44; ♀: 31. HW: 31.

Wings hyaline, almost reaching the seventh [abdominal] segment, fairly narrow, stalked up to about the basal third of the quadrilateral; the latter short, extending less than halfway up between the arculus and nodus. CuP a little closer to the arculus than to the first Ax. Pt dark brown, surmounting three cells, slightly oblique distally, pointed proximally, touching the costal margin at its terminal two-third. About twenty Px in the fore wings.

[Head] Brown above, yellowish below. Labrum, anteriorly rimmed with a line, some designs between the eyes, and the rear of the head yellow. Prothorax and front of synthorax [mesepisterna] brown, having on each side [of the mesepisternum] a rounded oval yellowish spot and the sides [remainder of the thorax] yellow. A narrow basal ring on S3–7, the posterior half of S8, [and] S9–10 entirely yellowish. Legs dirty yellowish.

Anal appendages yellowish, the cerci twice as long as S10, cerci robust slightly hairy externally, swollen below the base and having, after the middle, a very strong rounded, flattened inner tooth. The paraprocts large, rounded, very short, barely visible.

♀? (1) [♀ later synonymized with H. ochraceum ].

Country: Brazil, after a male in the St. Petersburg Museum that I reviewed and illustrated there fifteen years ago [this specimen is now lost].

NB. I do not have this species before me, but from my description and my drawing, it should resemble the dorsale differing by the two well-defined oval spots on the mesepisterna that are much smaller, non-contiguous, the absence of lateral lines black thorax and upper appendages more robust.”

At any rate, the H. ovatum specimens treated here represent very precisely the description by Selys. The only impediment to a fully correct diagnosis for this species is the lack of the originally described material. Its remarkably expanded BP region is unique among the genus (see Fig. 52 ), and its distribution is coherent with most Group A species.

Figures

FIGURE 52. Heteragrion ovatum: (a) lateral view of pterothorax; (b) anterior view of head, lateral view of thorax, and S1–2; (c–d) dorsal view of pterothorax; (e–f) mediodorsal view of cercus; (g–h) lateral view of cercus. BP: basal portion; MP: medial portion. Figures a–j provided by Rosser Garrison and Natalia von Ellenrieder.