Heteragrion aequatoriale Selys, 1886,

Bota-Sierra, Cornelio Andrés & Novelo-Gutiérrez, Rodolfo, 2017, The genus Heteragrion (Odonata: Zygoptera) in Northwestern Colombia, with the description of Heteragrion tatama sp. nov., Zootaxa 4347 (3), pp. 553-571: 557-559

publication ID

https://doi.org/10.11646/zootaxa.4347.3.8

publication LSID

lsid:zoobank.org:pub:505DF945-616E-42C0-B5A4-519D4E3A1212

persistent identifier

http://treatment.plazi.org/id/03B2274F-C27B-FFB4-4FA4-FBF58F4A1E55

treatment provided by

Plazi

scientific name

Heteragrion aequatoriale Selys, 1886
status

 

Heteragrion aequatoriale Selys, 1886 

Remarks. This species was described from males from Bogotá ( Colombia) and Bobonaza River area ( Ecuador). Calvert (1909) recorded the species with some variation in the coloration pattern in Peru (Piches and Perené Valleys), and briefly mentioned some characteristics of a teneral female specimen. Ris (1918) recorded four more specimens from Pozuzo, Peru. Williamson (1919), in his revision of the genus presented illustrations of some diagnostic traits of the specimens previously examined by Calvert, omitting the laterodorsal view of the cercus which is crucial for the reliable recognition of species in this genus. In 1970, Kimmins assigned a lectotype for the species with the following information: Type McLachlan labeled/ “ Bogota ”. He also pointed out that in the same box McLachlan grouped, as part of the type series, two specimens from Nueva Granada (name of Colombia from 1831 to 1858) that were not part of the description but had identification labels with Selys’s handwriting. Von Ellenrieder and Garrison (2007) illustrated the cercus of the Nueva Granada specimen in dorsolateral and dorsal views, with the dorsal view matching Williamson’s illustration of the Peruvian specimens. In July 2017 we examined the type series at BMNH but sadly all the specimens (Lectotype from Bogotá and Paralectotypes from Nueva Granada and Ecuador) lack the last abdominal segments from S7–S10, missing the principal morphological characteristic in this genus. We identified specimens by comparison with the type series, topotype material from Bobonaza River, and von Ellenrieder and Garrison (2007) illustrations of the type from Colombia ( Nueva Granada) deposited at IRSNB. Since H. aequatoriale  has not been found again close to Bogotá, and not even in the same mountain range (Colombian Cordillera Oriental), probably this locality is erroneous, as most Colombian material collected during the XIX century is labeled “ Bogotá ”, even though it sometimes came from another place in the country. This species was found only in the Central and Occidental Cordilleras, where we observed very similar patterns in face coloration among the populations present along the western slope of the Cordillera Occidental, one of the populations in the Central Cordillera, and Ecuadorian populations ( Fig. 3a, c, eView FIGURE 3). Contrastingly, populations present along the eastern slope of the Cordillera Occidental, and most of the populations from the Cordillera Central, vary

in face coloration pattern, with the black stripe on frons extending to genae ( Fig. 3b, d, fView FIGURE 3) or becoming brown on lateroposterior areas of frons ( Fig. 3gView FIGURE 3). Nevertheless, we consider this just intraspecific variability in H. aequatoriale  because all of them have the same cercus morphology. This variability in the color pattern was reported by Williamson (1919) in H. alienum  and H. triangulare  , also by Lencioni (2013) and Garrison (pers. comm.) for Heteragrion silvarum Ris, 1918  , raising some questions such as: Why is this variability only recorded in a few species of the genus? Is it due to lack of sampling for some species? Further studies comparing these populations are needed in order to establish if they are really the same species.

Description of female. Material Examined. COLOMBIA, Risaralda Department, Tatamá National Park, Pueblo Rico Municipality, Monte Bello Township: 3♀♀, Minas de Cuarzo stream, 5.22861°N 76.09806° W 1,480m a.s.l. 17 September 2014, Leg: M. Loaiza, A. Chinome, C. Flórez and C. Bota. 2♀♀, Cañón del Río Taibá, 5.22717°N 76.08283° W 1,530m a.s.l. 27 July 2016, Leg: J. Sandoval and C. Bota. 3♀♀, 8 August 2016, Leg: N. Uribe, J. Sandoval and C. Bota.

Head: yellow, but tip of mandibles, labrum, clypeus, antefrons, antennae, vertex, posterior half of frons and a stripe lateral to antennal base black ( Fig. 3hView FIGURE 3). Prothorax: yellow with anterior lobe of pronotum black and a middorsal stripe that reaches the posterior lobe and covers it completely, except for two symmetric yellow spots on lateroposterior border ( Fig. 4aView FIGURE 4); intersternite with a curved carina under dorsoposterior end which is rounded as in Figure 4gView FIGURE 4. Synthorax: dull yellow, but black wide middorsal and antehumeral stripes; dull black mesepimeral stripe reaching spiracle, and brown metepimeral stripe fading basally ( Fig. 5e –fView FIGURE 5). Legs: coxae dull yellow; pro- and mesofemora externally black, internally brown; metafemur brown becoming black apically; pro- and meso tibiae black; metatibia brown; armature and tarsus black; spines larger than the space between them, becoming longer towards the apex on femora, and shorter towards the apex on tibiae ( Fig. 5e –fView FIGURE 5). Wings: clear with slight yellowish tinge; venation black; dark brown pterostigma overlying 1 1/2 to 2 cells, the proximal side oblique; two postquadragular cells in FW and HW, 22–24 Px in FW, 19–20 HW. Abdomen: brown, with yellow middorsal line from S1 to S7; black on dorsum of S1–S3, apical wide rings on S3–S7; dull yellow sides of S1–S4, basal rings on S3–S7, sides of S9–S10, genital valves and paraprocts ( Fig. 5e –fView FIGURE 5); genital valves with one row of black denticles increasing gradually towards the apex; stylus black; cercus conical, dull yellow with apical black tip ( Figs 5a, eView FIGURE 5; 9c).

Measurements (mm): FW = 29.7–32.3; HW= 28.6–31.4; Abdomen= 35.5–38.8; Total= 44.8–49.2.

Biology: This species is present in small 3rd to 4th order rivers, usually within well-preserved forest. Males are usually seen perching on the hanging vegetation and twigs which are very close to waterfalls. Females are generally found in forest near the rivers. In Tatamá National Park this species is sympatric with H. tatama  , the latter dominating at first and second order streams inside the forest. There are some places where both species can be found together, like the confluence of small streams. In the Central Cordillera, H. aequatoriale  is found together with H. m. mitratum  in localities close to 1,000m a.s.l., where H. m. mitratum  is confined to smaller streams (1st to 3rd order aprox.), while H. aequatoriale  inhabits the larger ones (3rd to 4th order approx.).

A tandem pair was found at the Taibá river Canyon in Tatamá National Park, while the male was transferring the spermatophore from the tip of its abdomen to its genital ligula on a sunny day of June at 11:53am. The pair remained in copula until 12:05pm (12 minutes, Fig. 5eView FIGURE 5). Then they flew in tandem to the vegetation hanging from the stony walls of the canyon associated to a waterfall, which was gushing water continually along it, where the female began inserting their eggs ( Fig. 5fView FIGURE 5).

IRSNB

Institut Royal des Sciences Naturelles de Belgique