Heteragrion gorbi, Cezário & Guillermo-Ferreira, 2021

Cezário, Rodrigo Roucourt & Guillermo-Ferreira, Rhainer, 2021, Heteragrion gorbi sp. nov. (Odonata: Heteragrionidae) from southeastern Brazil, Zootaxa 4965 (1), pp. 78-86 : 79-85

publication ID	https://doi.org/ 10.11646/zootaxa.4965.1.3
publication LSID	lsid:zoobank.org:pub:C3D9CF34-7FFD-4EA7-84DE-7DE8198B223C
DOI	https://doi.org/10.5281/zenodo.4814569
persistent identifier	https://treatment.plazi.org/id/03D587BD-FFA0-6955-FF00-B5AF8EA0304C
treatment provided by	Plazi
scientific name	Heteragrion gorbi
status	sp. nov.

Treatment

Heteragrion gorbi sp. nov. Cezário & Guillermo-Ferreira, 2020

( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype. ♂ ( LESTES) BRAZIL, São Paulo, São Carlos, Cerrado UFSCar, Espraiado (-21.981569, -47.873922), 845 m asl, 29-ix-2020, Cezário & Guillermo-Ferreira, leg. GoogleMaps

Paratypes. 5 ♂♂ and 1 ♀ ( LESTES) . 2♂♂ ( LESTES) BRAZIL, São Paulo, São Carlos, Cerrado UFSCar, Espraiado (-21.981569, -47.873922), 845 m asl, 29-ix-2020, Cezário & Guillermo-Ferreira, leg GoogleMaps ; 2♂♂ and 1♀ ( LESTES) BRAZIL, São Paulo, São Carlos, Cerrado UFSCar, Espraiado (-21.981569, -47.873922), 845 m asl, 2-x-2020, Cezário & Guillermo-Ferreira, leg (one male and female caught in tandem) GoogleMaps ; 1♂ ( LESTES) BRAZIL, São Paulo, São Carlos, Cerrado UFSCar, Espraiado (-21.981569, -47.873922), 845 m asl, 31-x-2019, Cezário & Guillermo-Ferreira, leg. GoogleMaps

Etymology. In honor of Stanislav N. Gorb for his mentorship and contribution to odonatology.

Description of Holotype

Head. Labrum black with a medial blue spot; base of mandibles and genae light blue; postclypeus bluish; antenna and antefrons black; pale spots lateral to each lateral ocellus; pigmented ocellus; black postocular lobes; posterior margin of head dark ( Fig. 1b View FIGURE 1 ).

Thorax. In lateral view, anterior lobe of prothorax blue with an anterior pale spot; middle lobe blue with a pale spot; propleuron blue with a posterior pale spot anteriorly; posterior lobe dark ( Fig. 2a View FIGURE 2 ). Pterothorax black dorsally; mesepisternum black middorsally, while blue along mesopleural suture; mesepimeron with a black wide stripe; metepisternum black with blue margins; metepimeron black with a blue ventral stripe ( Fig. 2a–b View FIGURE 2 ). Legs: pro- and mesocoxa blue; metacoxa pale with black spots; profemur black laterally with a few pale spots; meso- and metafemur black laterally; metatibia pale laterally; spines of equal length along femur and tibiae; in anterior leg, spines longer than the space between them; while in medial and posterior legs, spines shorter than the space between them ( Fig. 1a View FIGURE 1 ).

Wings. Hyaline, Hw almost reaching S8; dark venation; pterostigma dark brown covering almost two cells in hindwings, and one cell entirely and part proximally of the posterior and anterior cells in forewings; proximal side of pterostigma obliquely projected in both wings; 15 Px in Fw, 12 in Hw ( Fig. 2c View FIGURE 2 ).

Abdomen. S1 dorsally black and bluish laterally; dark on S2–9; pale basal rings on S3–7; pale distal ring in S8; S10 ventrally pale; two distinguishable denticles in mid-ventral portion of S10 ( Figs. 1a View FIGURE 1 , 5a View FIGURE 5 ).

Anal appendages. Cercus in lateral view: small dorsobasal and ventrobasal expansions present; medial portion of cercus slightly shorter than apical portion ( Figs. 1 c–g View FIGURE 1 , 7a View FIGURE 7 ). Cercus in medio dorsal view: ventrobasal expansion curving inwards proximally, forming a semi-ellipsoid lobe; medial portion of cercus dilated almost forming a semicircular tube, ventral branch of medial process bilobed with a peak-like apex and straight ridge; apical portion curved inwards, with acute ending ( Figs. 1 c–g View FIGURE 1 , 7a View FIGURE 7 ). Cercus in ventral view: ventrobasal apophysis not present. Lacking elongated paraprocts ( Figs. 1 c–g View FIGURE 1 , 7a View FIGURE 7 ).

Measurements (in mm). Fw 23.0; Hw 22.7; Abdomen 27.9; Cerci 1.1; Total 36.7.

Variation in male paratypes. Wings: Fw with 13–15 Px; Hw 11–14 Px. Hw reaching S8 sometimes half of the S7. Two male paratypes are currently stored in the dry collection of the LESTES laboratory; in dorsal view the pterothorax of these two males presents two distinct copper stripes on each side (possibly postmortem effects).

Description of female

Head. Labrum black with a medial yellow spot; anteclypeus yellow; postclypeus black with a yellow spot in center and yellow spots in lateral region; antefrons yellow with a dark spot extending from postclypeus to its medial region; yellow spots lateral to each lateral ocellus; pigmented ocellus; posterior region of the head yellow with wide dark spot in medial region ( Fig. 3b View FIGURE 3 ).

Thorax. Prothorax in dorsal view: anterior lobe black with yellow spots in lateral region; middle lobe black with two elliptical yellow spots; posterior lobe black with yellow spots in lateral region ( Fig. 4a–b View FIGURE 4 ). Prothorax in lateral view: entirely yellow. Pterothorax black dorsally with two thin copper stripes from anterior to posterior region; mesepisternum black middorsally, while blue along mesopleural suture but not reaching the edge of the posterior region; mesepimeron black with blue coloration along interpleural suture and along posterior half region of mesopleural suture; metepisternum bluish with a dark stripe medially and a greenish blue coloration along interpleural suture; mesinfraepisternum greenish blue in its upper portion and black in its lower portion; metinfraepisternum greenish yellow ( Fig. 4a–b View FIGURE 4 ). Legs: pro-, meso- and metacoxa pale with scattered small black spots in center; femur and tibia pale laterally; spines increasing gradually in size from femur to tibia; two rolls of spines in tarsi; spines longer than the space between them ( Fig. 3a View FIGURE 3 ).

Wings. Hyaline, Hw reaching S9; dark venation; pterostigma dark brown; proximal side of pterostigma obliquely projected in both wings; 15 Px in right Fw, while 14 Px in left Fw; 13 Px in right Hw and 14 Px in left Hw ( Fig. 4c View FIGURE 4 ).

Abdomen. S1 pale; S2–10 dorsally black; pale basal rings on S3–7 ( Figs. 3a View FIGURE 3 , 5b View FIGURE 5 ). Denticles all along the distal edge of S10 ( Fig. 3c View FIGURE 3 ). Genital valves of ovipositor with ventral edge containing teeth disposed in two rows; stylus black; cercus conical, yellow on its base and black apical tips ( Fig. 3c–e View FIGURE 3 ).

Measurements (in mm). Fw 24.2; Hw 23.0; Abdomen 27.1; Cerci 0.6; Total 35.4.

Differential diagnosis. Males of Heteragrion gorbi sp. nov. lack elongated paraprocts ( Figs. 1a, 1c–g View FIGURE 1 ; 5a View FIGURE 5 ), and females present several rows of teeth on the ventral surface of the genital valves ( Fig. 3e View FIGURE 3 ); therefore, this species fits into Lencioni’s Group A (Selys’s group 1 and 2). Furthermore, along with H. cinnamomeum Selys, 1862 , H. gracile Machado, 2006 , H. ictericum Williamson, 1919 , H. tiradentense Machado & Bedé, 2006 , H. johndeaconi Lencioni, 2013 , and H. denisye , H. gorbi presents the apical portion of cerci smaller than the medial and basal portion (see Lencioni 2013 for a revision of Heteragrion Group A). Heteragrion gorbi can be distinguished from H. cinnamomeum , H. gracile and H. ictericum by the presence of a prominent ventrobasal expansion in the basal portion of cercus ( Fig. 1c View FIGURE 1 ). The presence of a bilobed process on the medial portion of cercus in H. gorbi ( Fig. 1f View FIGURE 1 ) is an important feature that distinguishes this species from H. tiradentense and H. johndeaconi . Heteragrion gorbi exhibit Fw with 13–15 Px and Hw 11–14 Px ( Fig. 2c View FIGURE 2 ), but never 18 Px in FW, 16 HW as in H. denisye .

In respect to the other Heteragrion species that present blue color patterns, H. gorbi differs from H. cyane (Lencioni’s group A) mainly by its bilobed MP in medial process with the distal tip sharply pointed ( Fig. 1f View FIGURE 1 ). Heteragrion azulum (possibly Lencioni’s group B) is known from one individual collected in Veracruz, Mexico, and can be diagnosed by its paraproctal spines hooked dorsally, differing from H. gorbi which does not present visible paraproctal spines. Lastly, because of the brief description of H. obsoletum (Lencioni’s group A) available in the literature and the fact that the holotype is lost, our comparison was restricted to the fact that H. obsoletum presents “ un renflement ou dent interne arrondie après leur milieu ” (Selys 1886), in other words insinuating the existence of a rounded process after the mid portion of the cerci. With no more details available, we propose that H. gorbi can be distinguished from H. obsoletum by the presence of a bilobed MP with the distal arm sharply pointed.

We also compared the holotypes of H. gorbi to H. denisye , which is another species with blue/black color patterns. Concerning the cerci, males of H. gorbi present a rounded angle between the medial portion and apical portion of the cercus, while in H. denisye an acute angle is present ( Fig. 7a–b View FIGURE 7 ); also, the angle formed between the bilobed process of the medial portion is wider in H. gorbi than in H. denisye , and instead of a blunt bilobed tip on MP like in H. denisye , H. gorbi presents a sharply pointed distal tip of the MP ( Fig. 7a–b View FIGURE 7 ). Finally, H. denisye was collected in Serra da Canastra, Minas Gerais, an open field Cerrado located 250–300 km from H. gorbi type locality, which is a riparian forest with closed canopy in São Carlos, São Paulo.

Habitat and Ecology. The specimens were found perching on Pteridium sp. (Dennstaedtiaceae) and Hedychium coronarium J. König (Zingiberaceae) , in a stream (approximately 1 m wide) surrounded by riparian vegetation ( Fig. 6 View FIGURE 6 ). The area is formed by a natural spring and is predominantly shaded with a reasonable number of sunny patches. In the same habitat, we also collected Hetaerina longipes Hagen in Selys, 1853, H. rosea Selys, 1853 , Mnesarete guttifera (Selys, 1873) ; Argia reclusa Selys, 1865 ; Acanthagrion lancea Selys, 1876 ; Oxyagrion evanescens Calvert, 1909 ; Tigriagrion aurantinigrum Calvert, 1909 and Telebasis carmesina Calvert, 1909 (Zygoptera: Coenagrionidae ); Heteragrion aurantiacum Selys, 1862 ; an unidentified gomphid and a Castoraeschna sp. (Anisoptera: Aeshnidae ).

Final remarks. Heteragrion gorbi was found in a Cerrado fragment with a singular vegetation and fauna due to its altitude and climate. Recent conservation efforts have insistently fought against threats to deforestation, all of which are projects of urbanization: the construction of a road, buildings for the Federal University of São Carlos and the expansion of residential areas. The urbanization process and sugar cane plantations around the area certainly affect local biodiversity, including H. gorbi , a species that was only found in a small and restricted site. The spring where H. gorbi was found is one of the major water sources for the city, and its conservation is not only crucial for biodiversity conservation but also for human daily water consumption.

The discovery of H. gorbi in an area surrounded by monoculture and highways gives us hope for the conservation acts that have been protecting the area, but it also reminds us of the risks that natural environments and wildlife are going through today in Brazil. We hope that this new species becomes a flagship to support local efforts for the conservation of the Espraiado stream and the surrounding Cerrado fragments, which might become an example to state and even national politics for the conservation and maintenance of natural environments and wildlife of the Cerrado.