Forcepsioneura regua, Pinto & Kompier, 2018

Pinto, Ângelo Parise & Kompier, Tom, 2018, In honor of conservation of the Brazilian Atlantic Forest: description of two new damselflies of the genus Forcepsioneura discovered in private protected areas (Odonata: Coenagrionidae), Zoologia (e 21351) 35, pp. 1-19 : 3-7

Forcepsioneura regua sp. nov.

http://zoobank.org/ 389F29AC-9E25-4154-80ED-C92FAFE9801C

Figs 1–6, 17–20, 24–28, 31–32, 35, 37

Forcepsioneura garrisoni nec Lencioni, 1999: — Costa and Oldrini (2005: 200, 208, key, misidentification of specimens from Rio de Janeiro State,Ilha da Marambaia island); — Anjos-Santos and Costa (2006: 41, misidentification based on Costa and Oldrini 2005).

Forcepsioneura haerteli nec Machado, 2001: — Pessacq et al. (2012: 6, misidentification of a male from Rio de Janeiro State, Cachoeiras de Macacu, Japuíba, Santana River).

Forcepsioneura sp. : — Garrison et al. (2010: 358–360, 479, figs 2380, 2383, 2386, 2389, illustrations of wings, middle and posterior lobes of prothorax in laterodorsal view, and caudal appendages in lateral and dorsolateral views of a male from Ilha da Marambaia island, Rio de Janeiro State, Brazil); — Kompier (2015): 112–113, photos of male and female habitus on the field from the type locality, characterization, comparison with Epipleoneura venezuelensis , F. lucia , and F. sancta , notes on habitat and behavior).

Diagnosis. Small, dorsally metallic greenish-blue, lateroventrally light blue and yellowish striped protoneurid; frons angulated; rear of head pale; CuP&AA indistinct; Ax space 1 as long as Ax space 3; GL with long inner fold and distal lateral lobe prolonged into a flagellum; cercus forcipate with mediobasal (MBP) and ventrobasal (VBP) processes, except for ill-defined prothoracic tubercle-like process, all characters agreeing with the definition of Forcepsioneura as recently diagnosed (Machado 2009, Garrison et al. 2010).

The comparatively longer VBP, longer than 0.53 of total cercus length (dorsal branch) in lateral view, allows separation of males of F. regua sp. nov. from species of the orange-black group (VBP ≤ 0.40 of cercus length in F. grossiorum , F. lucia , and F. serrabonita sp. nov.); anteromesal margin of MBP acute in dorsal view ( Fig. 25) separates it from F. sancta (largely rounded in dorsal view; sensu Machado 2001); apex of VBP acute and MBP not visible in lateral view ( Figs 5, 24) from F. itatiaiae (apex of VBP truncated and MBP visible in lateral view); VBP shorter, not reaching ventral margin of S 10 in lateral view, and apex strongly curved internally ( Figs 5, 24–26) from F. haerteli (which has a longer VBP at level of S10, and apex slightly curved internally).

Based on its general color and size, F. regua sp. nov. is most similar to F.garrisoni . Indeed, these two species are remarkably similar due to the blue stripes on thorax (light blue group). The short MP vein, which reaches distally at most 0.5 of the length of cell distal to the vein descending from subnodus, and the fin-shaped plate of MBP with an acute and strongly anteriorly directed apex in laterodorsal view are unique to these two species and separate them from all other known species in the genus. The short VBP, not reaching ventral margin of S10 ventrally, and posterolateral margin of median lobe of prothorax lacking a defined tubercle-like process distinguish F. regua sp. nov. from F. garrisoni (VBP long, ventrally reaching the ventral margin of S10, and posterolateral margin of median lobe of prothorax with a strongly defined conical tubercle-like projection). The ill-defined process on prothorax is unique for F. regua sp. nov. ( Figs 1–3, 17, 27–28).

Despite the fact that the blue coloration and the ill-defined process on the prothorax of F. regua sp. nov. appear to be unique to females of this species, females of other Forcepsioneura are poorly known. Consequently, females should be identified through comparison with descriptions, figures, and their association with males.

Description of the male holotype. Head ( Figs 1–2): Labium, visible parts of maxilla and mandibles (except apex) ivory yellow. Genae yellowish, darkening gradually posteriorly. Labrum dark brown to black with ventral 0.25 yellowish-orange, extended to 0.50 mesally, areas close to clypeolabral suture paler. Anteclypeus with lateral and mesal membranous ventral part yellowish, remainder part forming a rectangular black plate, postclypeus shining black. Antefrons, postfrons and remainder of epicranium black with shining bluish metallic reflections after postfrontal suture over postocular area. Antenna, antennifer and scape black, posterior surface of pedicel light brown, all parts with laterofrontal surface and distal apex of scape ivory yellow; flagellum lost. Posterior region of the cranium (“postgena” plus “occiput”) ivory yellow, 0.33 dorsal brownish-black.

Thorax ( Figs 1–3, 17): Prothorax dorsally black, gradually lightening ventrally to brown laterally, ventral 0.3 of pleural sclerites yellow, notum with a ventrolateral whitish-blue stripe; anterior margin of anterior lobe black mesally, yellow laterally,

posterolateral margin of median lobe with a very weak projection resembling the tubercle-like process observed in other Forcepsioneura ( Figs 3, 17); posterior lobe asymmetrically convex, narrower than median lobe in dorsal view, right half slightly deformed ( Fig. 17); sternellum (furcasternum sensu Asahina 1954) almost entirely black. Synthorax ( Fig. 35) dorsally dark, gradually lightening ventrally; mesepisternum from mesostigmal region to antealar sinus dark brown to black with bluish metallic reflections, with a brown stripe occupying 0.33 of width running longitudinally to mesopleural suture; mesepimeron and metepisternum brown with irregular darker areas and a wide light blue longitudinal stripe running from posterolateral angle of mesinfraepisternum to antealar processes, occupying at maximum 0.33 of mesepimeron to 0.80 of metepisternum width, a mesal dark dot at level of intersegmental suture; metepimeron ivory yellow with a small brown area close to metapleural suture posteriorly; metapostepimeron ivory yellow with a black spot at lateroventral angle. Legs ivory yellow with irregular dark brown to black areas in the articulations of femur-tibia and tarsal segments, dorsal surface of femora, tibiae and apex of pretarsal claws (pretarsus); spurs black, except scale-like ivory yellow two proximal femoral spurs and tibial comb of prothoracic leg; anteroventral surface of femora armed with long and robust spurs, three in pro-, four in meso- and metathoracic femora, posteroventral surface with shorter and thinner spurs, 5 in pro-, 5–6 in meso- and 6–8 in metathoracic femora; anteroventral surface of tibiae armed with 9–10 spurs in pro- (4–5 of tibial comb), 5–6 in meso-, 6 metathoracic, length similar to intervening spaces; pretarsal claws with distinct acute supplementary inferior tooth at ca 0.50 of their length in all legs.

Abdomen ( Figs 31–32): Tergites of S1–10 dark brown to black dorsally, light brown to ivory yellow lateroventrally, distinctly darker in S8–10; tergites with a very thin pale line along the dorsal carina on S1–8; sternites similar in color to adjacent areas of tergites except 0.5 posterior of S8 dark brown with a transverse posterior yellow stripe contiguous to and with similar width of yellow posterior field of tergite. Ovipositor ( Fig. 32) distally reaching level of cercus in lateral view, dark brown, lightening distally, dorsal lobe of third valve (gonoplac of S9) yellow, ventral surface smooth; stylus dark brown, tip yellow. Cercus, epiproct and paraproct dark brown to black.

Measurements (mm). Total length (incl. caudal appendages) 35.2; abdomen length (excluding caudal appendages) 30.5; head maximum width 2.9; Fw length 21.2; Hw length 20.2; Fw maximum width 3.7; Hw maximum width 3.8; Pt length 0.53 in Fw; 0.54 in Hw; length of metathoracic femur 2.0; metathoracic tibia 2.2; length of S9+ 10 in lateral view 1.0; total length of cercus in lateral view 0.28.

Variation in male paratypes. The nine other males are very similar to holotype except for minor differences described below.

Head:Antefrons ivory yellow with a mesal ill-defined brown line; occipital bar with a yellow spot. Flagellum dark brown. Thorax: Prothorax paler with whitish-blue ventrolateral stripe faint; posterior lobe truncated or with small median concavity. Light blue longitudinal stripe on synthorax occupying at maximum 0.5 of mesepimeron width to almost entire metepisternum. Long and robust spurs on anteroventral surface of femora 3–4 in pro-, 4 in meso- and 4–5 in meta-, posteroventral surface with shorter and thinner spurs, 3–5 in pro-, 4–6 in meso- and 5–8 in metathoracic femora; anteroventral surface of tibiae armed with 9–11 spurs in pro- (4–5 of tibial comb), 5–6 in meso-, 5–6 in metathorax.

Abdomen: Paraproct orange-yellow to dark brown.

Measurements (mm, n = 5). Total length (incl. caudal appendages) 31.7–35.9; abdomen length (excluding caudal appendages) 27.0–30.8; head maximum width 2.8–3.0; Fw length 17.3–19.2; Hw length 16.5–18.0; Fw maximum width 3.0–3.5; Hw maximum width 2.9–3.3; Pt length 0.44–0.58 in Fw; 0.46– 0.58 in Hw; length of metathoracic femur 1.7–1.9; metathoracic tibia 1.9–2.1; length of S9+ 10 in lateral view 1.1–1.3; length of cercus (dorsal branch) in lateral view 0.42–0.60; length of ventrobasal process in lateral view 0.30–0.36.

Larva. Unknown.

Material examined (10 males, 2 females). Holotype male and paratype female (in tandem), BRAZIL. Rio de Janeiro State: Cachoeiras de Macacu municipality, Reserva Ecológica de Guapiaçu ( REGUA), forest fragment (22°28’08”S, 42°45’39”W, 42 m a.s.l.), 27.VII.2012, T.M.F. Kompier leg. ( DZRJ 2071 ); 1 male paratype, same data but pond with macrophytes (22°27’10”S, 42°46’13”W, 34 m a.s.l.), 03.XII.2009, A.L. Carvalho & Disciplina Técnicas de Coleta PPGZoo/UFRJ leg.( DZRJ 315 , DNA voucher ENT3609 ); 1 male paratype, same data but stream at small wetland (22°25’51”S, 42°45’39”W, 75 m a.s.l.), 02.III.2013, T.M.F. Kompier leg. ( DZRJ 326 ); 2 male paratypes, same data but 22°28’04”S, 42°45’32”W, 70 m a.s.l., 13.I.2014, ( DZRJ 2251 , DNA voucher ENT2854; DZRJ 2252 , DNA voucher ENT3608 ); 1 male paratype, same municipality but [District of] Japuíba [22°33’46”S, 42°41’30”W, 26 m a.s.l.], Rio Santana (sic, Rio Macacu ?), 08.V.1983, J.M. Costa leg. ( MNRJ ODO-0011, DNA voucher ENT2368 ); 2 male paratypes, Mangaratiba municipality, Ilha de Marambaia , Gruta da Santa (23°03’35”S, 43°57’56”W, 100 m a.s.l.), 02.XII.2000, R.W. Garrison leg. ( RWG, DNA voucher ENT3016; DZUP 498845 ); 1 male and 1 female paratypes, same data but 04.XII.2000 ( RWG); 1 male paratype, same data but temporary pool close to areal (MNRJ-ODO 0208, DNA voucher ENT3607 ). Specimens in DZRJ collected under ICMBIO/SISBIO license numbers 25034-1, 25034-2, and 25034-3.

Biological and ecological data. Males were observed at seeps from peaty substrate at the forest edge and on very shallow, small streams with abundant leaf litter and limited flow. Even though observations were made on sunny days, they seem to avoid direct sunlight, perching suspended from the tips of leaves and grasses, or on the leaf litter. Streams were either partially or fully covered by trees and bushes. Females were observed in the same habitat. Both males and females were seen flying very slowly, and appeared to float in the air. Copulation lasted up to 10 minutes. Females were observed ovipositing unattended on a muddy substrate. Their habitat was shared with Heteragrion aurantiacum Selys, 1862 , H. consors Hagen in Selys, 1862 and Acanthagrion gracile (Rambur, 1842) , species that are tolerant to disturbed habitats in typical southeastern Brazilian Atlantic Forest.

Etymology. Noun in apposition in reference to the acronym of the type locality, Reserva Ecológica de Guapiaçu (REGUA), a private reserve maintained for conservation, scientific research and environmental education.

Remarks. This species has been known to specialists for at least eighteen years (e.g., Garrison 2000). Some specimens of the type series of F. regua sp. nov. had been previously determined as F. garrisoni , F. haerteli or F. sancta by distinct specialists. For example, Costa and Oldrini (2005) cited this species as F. garrisoni from Ilha da Marambaia island in Rio de Janeiro, and provided an illustration of the cercus in laterointernal view (their fig.30). Even though that illustration agrees with F.garrisoni , we think that it was modified from the original description of that species. We believe this because other illustrations in that paper were clearly extracted from previous works, and reproduced with minor modifications. Individuals of the population from Ilha da Marambaia island are distinctly larger than those from the type locality in REGUA.