Metaleptobasis truncata, Ellenrieder, 2013

Ellenrieder, Natalia Von, 2013, A revision of Metaleptobasis Calvert (Odonata: Coenagrionidae) with seven synonymies and the description of eighteen new species from South America , Zootaxa 3738 (1), pp. 1-155 : 75-77

publication ID	https://doi.org/ 10.11646/zootaxa.3738.1.1
publication LSID	lsid:zoobank.org:pub:77D1A6F6-C320-442B-AF31-83324E5EAF3B
persistent identifier	https://treatment.plazi.org/id/03E187ED-667C-FFF4-D7A8-F9BAE0DAFDC7
treatment provided by	Felipe
scientific name	Metaleptobasis truncata
status	sp. nov.

Treatment

Metaleptobasis truncata View in CoL new species

Figs. 1 View FIGURE 1 ad; 3ad; 4ad; 5ad; 6c; 8ad; 9ac; 10ad; 11ad; 12ad; 14d

Etymology. From Latin truncatus (verb), meaning 'cut off', in reference to the truncate apex of male cerci.

Types. ( all *)— Holotype ♂: BRAZIL, Pará State , Jacareacanga {6°16'S, 57°39'W}, xi 1969, F.R. Barbosa leg. [ UMMZ]; 2 ♀ paratypes: same data as holotype [ UMMZ]; 1 ♀ paratype: Pará State, Rio Xingu Camp, ca. 60 km S of Altamira, first jungle stream, trail 1 (3°39'S, 52°22'W), 4 x 1986, P. Spangler & O.S. Flint, Jr. leg. [ USNM]. GoogleMaps

Specimens examined. Total: 1 ♂, 3 ♀.

Description of male holotype. Labium and rear of head pale yellow; base of mandible pale bluish yellow; labrum pale blue with dark brown line along latero-basal margins; eyes brown, color in life unknown; gena pale blue with a brown spot to the side of antefrons; anteclypeus pale blue with a pair of diffuse lateral brown spots; postclypeus pale blue with a dark brown spot on each antero-lateral corner; antefrons pale blue with yellowish central area; postfrons and epicranium pale bluish brown with black areas as depicted in Fig. 1 View FIGURE 1 ad i; postocular lobes slightly angled. Thorax. Color as described for genus, with mid-dorsal dark stripe on pterothorax black with metallic green reflections, narrower than inter-laminal sinus, as wide as 0.25 of mesanepisterna width, with straight sides, slightly widening posteriorly ( Fig. 3 View FIGURE 3 ad i). Pronotum anterior and middle lobes smooth; anterior margin of middle lobe of pronotum very close to posterior margin of anterior lobe dorso-laterally, separated from it by a very narrow fissure, and fused to it laterally; anterior area of propleuron with a vertical ridge formed by anterior lobe lateral margin projected antero-ventrally and a sub-vertical c-shaped crest posterior to it (l.c.; Fig. 4 View FIGURE 4 ad i); pronotum posterior lobe ( Fig. 5 View FIGURE 5 ad i) trilobed, with medial lobe smoothly convex, and lateral lobes entire and smoothly convex, shorter than medial lobe, with lateral corners rounded (on right) or slightly angled (on left). Mesanepisternal horns with bases adjacent, left horn (right horn broken off from base) as long as two times mesostigmal plate width, of medium thickness, cylindrical, directed antero-dorsally at an angle of 65° with dorsum in lateral view, ending in a bluntly pointed tip. Wings hyaline, veins reddish brown; Pt trapezoidal, with anterior side shorter than distal side, and membrane dark reddish brown margined by pale reddish brown; 13 pnx in Fw, 12 in Hw. Abdomen. Postmortem background color pale yellowish blue on S1–10; S1 with a reddish brown dorsoposterior spot; dorsum of S2–5, 7 dark reddish brown, with a basal pale incomplete ring at anterior edge interrupted by a narrow medio-longitudinal reddish brown line, and with a small diffuse pale subapical transverse spot near posterior margin on each side, S6 missing, S8–10 pale reddish brown; intersegmental membrane on S1–5, 7 dorsally dark reddish brown; cercus reddish brown with apex black; paraproct pale yellow with about distal 0.50 brown and apex black. Genital lobe short, less than 0.50 of anterior hamule height, smoothly curved; posterior hamule digit-like and small, with tip not differentiated, shortly surpassing ventral margin of genital fossa in lateral view; curvature of basal segment of genital ligula marked by a slight concave depression; genital ligula distal segment sub-rectangular, with ratio maximum width/length of 0.40, narrower than basal segment, with apex slightly concave, lacking an ectal fold ( Fig. 8 View FIGURE 8 ad). Medial portion of male S10 postero-dorsal margin ( Figs. 10 View FIGURE 10 ad; 11ad; 12ad) projected posteriorly, with a longitudinal incision with margins thickened and apressed, with a dorsal prominence surrounding incision. Cercus sub-cylindrical, of uniform width, slightly and gradually curved medially in dorsal view ( Fig. 10 View FIGURE 10 ad), tip blunt, truncate posteriorly ( Fig. 11 View FIGURE 11 ad), medio-ventrally with a small point; ratio of cercus length to S10 maximum length in lateral view 1.5; ratio of cercus length to paraproct length in lateral view 0.76; paraproct sub-cylindrical, distal 0.66 compressed with an inner concavity, with a sub-apical ridge on medial surface (r., Figs. 10 View FIGURE 10 ad; 11ad), about straight and parallel-sided in lateral view ( Fig. 12 View FIGURE 12 ad), slightly widening distally; tip curved medially at about 90°, ending on a single medio-ventral tooth (s.t., Figs. 10 View FIGURE 10 ad; 11ad).

Dimensions. Hw 21.1; abdomen missing S6.

Female paratype (same data as holotype). Head. As in holotype but labrum with dark dendritic marks; pale color of gena, anteclypeus, and antefrons pale bluish yellow ( Fig. 1 View FIGURE 1 ad ii).— Thorax. As in holotype ( Fig. 3 View FIGURE 3 ad ii) but posterior lobe of pronotum slightly trilobed, with medial lobe very short and narrow, shorter than lateral lobes ( Fig. 4 View FIGURE 4 ad iii); mesanepisternal horns represented by short pyramidal bases, as long as 0.33 of mesostigmal plate, directed antero-dorsally at an angle of 90° with dorsum in lateral view ( Fig. 5 View FIGURE 5 ad ii); Pt pale yellow.— Abdomen. Color pattern as in holotype but medio-longitudinal sternal carina on S2–8 narrowly black; posterior margin of S8 sternum smooth, lacking any denticles, spines, or processes ( Fig. 9 View FIGURE 9 ac); ovipositor surpassing slightly level of tip of cercus; caudal appendages and ovipositor valves reddish brown.

Variation in paratypes. As holotype but color of head as in female paratype, one paratype with and one without dendritic black marks on labrum; Pt yellow margined by reddish brown, with posterior side slightly longer and anterior side slightly shorter than distal side; ovipositor reaching level of tip of cercus; stylus dark reddish brown.

Dimensions. Females (n 3): Hw 22.8 ± 0.5 [21.1–23.3]; abdomen 35.4 ± 0.5 [34.9–35.8]; total length 43 ± 0.6 [42.3–43.5].

Diagnosis. Metaleptobasis truncata shares the combination of head dorsum with black pattern limited to isolated stripes, base of mesanepisternal horns adjacent, and two sub-vertical crests on anterior area of propleuron (l.c.; Fig. 5 View FIGURE 5 ad) only with M. diceras , M. lillianae , M. longicauda , and M. silvicola , and among them, anterior and middle lobes of pronotum separated dorso-laterally by a narrow fissure (f.) only with M. longicauda and M. silvicola ( Figs. 5q View FIGURE 5 , aa; vs. separated by a groove, Figs. 5f, p View FIGURE 5 ). It differs from them all by the width of mid-dorsal dark stripe of pterothorax, about 0.25 the width of mesepisterna ( Fig. 3 View FIGURE 3 ad), vs. about 0.33 in M. lillianae , about 0.20 in M. longicauda , and about 0.16 in M. silvicola ( Figs. 3p–q View FIGURE 3 , aa), and further from M. diceras , M. lillianae , and M. silvicola by its trapezoidal Pt, with anterior side shorter than distal side ( Fig. 6c View FIGURE 6 ; vs. Pt rectangular, Fig. 6a View FIGURE 6 ), from M. diceras and M. silvicola by tip of male cercus sub-cylindrical ( Fig. 11 View FIGURE 11 ad; vs. depressed dorso-ventrally, Figs. 11f View FIGURE 11 , aa), from M. diceras by sub-rectangular shape of distal segment of genital ligula ( Fig. 8 View FIGURE 8 ad; vs. pear-shaped, Fig. 8f View FIGURE 8 ), male cercus of uniform width in dorsal view ( Fig. 10 View FIGURE 10 ad; vs. widened distally, Fig. 10f View FIGURE 10 ), and male paraproct medial surface ending on a single medio-ventral tooth (s.t., Figs. 10 View FIGURE 10 ad; 11ad; ending on a bicuspidate tooth, Figs. 10f View FIGURE 10 ; 11f View FIGURE 11 ), and from M. lillianae by distal free portion of horns directed anterodorsally or reduced ( Figs. 4 View FIGURE 4 ad; 5ad; vs. directed laterally, Figs. 4p View FIGURE 4 ; 5p View FIGURE 5 ) and male cercus curved medially in dorsal view ( Fig. 10 View FIGURE 10 ad; vs. about straight, Fig. 10p View FIGURE 10 ).

All known females are dimorphic in the development of mesanepisternal horns, and dimorphic (33%) or not (67%) in the shape of the posterior lobe of pronotum.

Habitat. Forest near streams.

Distribution. Pará State in Brazil ( Fig. 14d).