Leptogenys elzasoares, Tozetto & Chaul & Lattke & Boudinot, 2022

Tozetto, Leonardo, Chaul, Júlio C. M., Lattke, John E. & Boudinot, Brendon E., 2022, Review of the Leptogenys unistimulosa species group (Hymenoptera: Formicidae) with the description of a new Amazonian species, Revista Brasileira de Entomologia (e 20220045) 66 (3), pp. 1-17 : 7-10

Leptogenys elzasoares new species urn:lsid:zoobank.org:act:BAFAC161-1AF8-46A5-83B9-B662086BD376 ( Figures 4 , 5 , 6 , and 11B)

Worker diagnosis

Head weakly rugulose in full-face view. Mandible mostly straight in full-face view, weakly widening apicad. Median clypeal lobe with 12 chaetae (= stout setae). Eye large, occupying one-third lateral cephalic margin. Hypostomal tooth not as long as mandibular width. Mesonotum wider than long. Propodeal dorsum transversely striate. Petiolar node with an acutely pointed posterior spine. Head, mesosoma and petiole black, antenna, legs and gaster brightly ferruginous.

Worker measurements

Holotype (Paratypes): EL 0.36 (0.34–0.36); CML 0.38 (0.34–0.40); ML 0.96 (0.92–0.96); SL 1.59 (1.58–1.60); HL 1.31 (1.26–1.31); HW 1.06 (1.06– 1.12); PW 0.87 (0.86–0.88); WL 2.36 (2.35–2.42); PetW 0.59 (0.59–0.62); PetH 1.07 (1.03–1.07); PetL 0.74 (0.70–0.75); OI 34.0 (30.6–33.0); MI 90.7 (82.1–90.6); SI 150.0 (142.3–149.1); CI 80.9 (84.1–85.5); DPI 79.2 (81.3–87.3); LPI 143.7 (137.3–152.8); (Paratypes = 3).

Head longer than wide in full-face view; wider anterad than posterad, posterior profile broadly convex, curving into broadly convex to straight lateral profile; vertexal carina visible. Mandible slender, mostly straight, gently bent at base, and widely separated from clypeus; mandibular dorsum smooth and shining, modestly widening apicad. Median clypeal lobe protruding, shorter than maximum scape width; apex semicircular; apex bearing 12 chaetae (= stout setae). Lateral clypeal lobe low, broadly convex. Epistomal sulcus well impressed between torulus and mandibular base. Hypostomal tooth visible in full-face view; shaped as curved triangular tooth. Antenna: scape surpasses posterior cephalic border by almost one-third its length; pedicel and flagellomeres (= funicular segments) longer than wide; fourth antennomere 75% the length of third antennomere.Compound eye large, convex, covering about one-third of lateral cephalic profile. Sculpture: Cephalic dorsum rugulose, sculpture softening laterally; ventrally smooth; clypeus with oblique to transverse striae; scape smooth and with punctulae.

Mesosoma. Promesonotum with profile broadly convex in lateral view. Pronotum lateroventrally smooth, laterally longitudinally rugulose; rugulae form arching, parallel striae extending across dorsum of segment. Mesonotum wider than long in dorsal view, transversely striate; posterior margin strongly inflected, metanotal groove appearing deeply impressed. Mesometapleural suture well impressed, forming elevated ridge above metapleural area.Metapleural-propodeal suture mostly impressed, becoming weak anteriorly. Propodeum with dorsal profile in lateral view forms very broad and weak convexity, being almost straight, and separated from declivity by blunt angle; propodeum unarmed. Sculpture: Mesopleural and metapleural areas with oblique striae; propodeal dorsum with transverse striae; declivity with transverse carinae; lateral propodeal face strigate-rugose to rugulose.

Metasoma. Petiole in lateral view with anterior margin strongly convex, curving to straight ascending dorsal profile that ends with acutely sharp tooth that overhangs posterior margin by almost one-third the length of node; dorsal margin of tooth approximates a 40° angle, and is closely aligned along longitudinal petiolar axis; posterior profile straight and sharply separated from lateral face. Petiolar node longer than wide in dorsal view; anterior profile shorter than posterior profile. Subpetiolar process subtriangular to rounded.Abdominal tergite III in lateral view with vertical anterior profile that becomes convex dorsad.Cinctus distinct on both abdominal tergum and sternum IV, but not strongly impressed. Abdominal tergum VII (= pygidium) broadly convex in lateral view. Abdominal sternum VII (= hypopygium) with stout setae. Sculpture: lateral face of petiolar node mostly smooth ventrad, with dorsal half coarsely strigate-rugose, posterior face striate. Gaster smooth and shining.

Setation. Body with erect to suberect hairs; median clypeal lobe with two long parallel hairs; scape with sub-decumbent hairs and decumbent pubescence; mesosoma and gaster lacking pubescence.

Color. Head, mesosoma, and petiole black; clypeus and procoxae black to brownish; antennae, mandibles, and most of legs ferruginous brown; gaster ferruginous.

Male diagnosis

Uniquely identified among the unistimulosa species complex by the following conditions: (1) Body size not very large (WL <3.00 mm); (2) ocelli grossly enlarged, distance between lateral ocellus and compound eye <1 lateral ocellus length; (3) ocelli surpassing posterior head margin in full face view; (4) compound eyes grossly enlarged, with the distance between them slightly more than one eye length in full-face view; (5) scape 1.5–2x pedicel length and slightly longer than clypeal length; (6) mesoscutum about as long as broad; (7) mesoscutum smooth and slightly rugose posteriorly; (8) vein M+Cu-f1 short; (9) 2r-rs longer than Rs-f4; (10) petiolar node bulging anterad at posterodorsal corner; (11) abdominal sternites AIII–VIII (gastral I–VI) with sparse hairs, without appearance of dense shaggy pads. The enlarged ocelli and compound eyes and the petiolar node form are the most conspicuous defining features of this species (chars. 2–4, 10).

Male measurements

EL 0.71; OL 0.15; OES 0.09; CML 0.35; ML 0.33; SL 0.36; HL 1.08; HW 1.225; MeL 1.00; MeW 0.94; WL 2.38; PetW 0.47; PetH 0.80; PetL 0.65; OI 58.0; MI 26.9; CI 113.4; SI 29.4; DPI 72.3; LPI 123.1; (n = 1).

Head in full-face view longer than wide, excluding eyes.Mandible slightly shorter than antennal scape, edged apically, dorsal surface smooth. Clypeus anterolateral margin straight with thin lamella, apex truncate. Frontal carinae reduced.Antenna: Scape 1.5–2x pedicel length and slightly longer than clypeal length; pedicel longer than wide. Compound eyes grossly enlarged; minimum distance between eyes slightly more than half eye length in full-face view and slightly more the maximum eye width. Ocelli large, equal in size, moderately protruding beyond posterior border of head; distance between compound eye and lateral ocellus less than ocellus width. Sculpture: Cuticle of head capsule mostly punctate.

Mesosoma with dorsal profile broadly convex in lateral view. Pronotum rugulose laterally.Mesoscutum in dorsal view slightly longer than wide; anteriorly and laterally smooth, rugose posterad of notauli. Notauli strongly impressed, scrobiculate.Parapsidal lines extend about half of mesoscutal length. Mesoscutellar disc longitudinally striate. Upper mesopleural area (= anepisternum) punctate and medially striate. Longitudinal mesopleural sulcus scrobiculate.Lower mesopleural area (= katepisternum) smooth. Mesometapleural suture well-marked. Propodeum in lateral view with angle between dorsal and descending margin; dorsally rugulose, declivity shining and with few carinae. Sculpture: propodeum and metapleuron mostly rugulose in lateral view.

Wings. Forewing as in L. bohlsi , but vein M+Cu-f1 very short, and 2r-rs longer than Rs-f4; hindwing veins mostly reduced.

Metasoma. Petiole with anterior profile broadly convex in lateral view, summit broadly truncate, posterior profile straight. Subpetiolar process tapered.Petiolar sculpture: lateroventral surface mostly rugulose, posterior face smooth with striae ventrally. Cinctus well marked. Gaster mostly smooth with sparse punctulae. Abdominal sternum IX posteriorly rounded.

Genitalia. Cupula (= basal ring) distinctly broadening posterad in dorsal view; dorsal surface longer than ventral surface but not considerably so, being about 2x ventral surface length; ventral surface deeply emarginate medially. Gonopod (= paramere) about three times as long as tall; gonocoxa and gonostylus about equal in length, as measured from their ventral inflection point. Gonocoxa (= basimere) dorsomedial margins evenly and weakly curving to gonostyli, with dorsal proximomedial margins not parallel; ventromedial margins long, with length of parallel margins about equal to width of gonocoxal base in ventral view. Gonostylus (= telomere/harpe) long and narrowly rounded apically. Volsellae appearing long. Penite (= penisvalva) with lateral process at base of valvura; lateral penital carina (= lateral apodeme) with broad and rounded proximal process; penital apex short, comparatively broad; serrations of ventral margin of variable stature, with serrations not distinctly projecting between the ventral curve and apical concavity.

Setation. Head with some long erect hairs and with fine decumbent hairs; clypeus with fine sub-decumbent hairs, anterad with long suberect hairs; antenna with short sub-decumbent hairs. Mesosoma, petiole, and gaster covered with erect hairs and sometimes with short sub-decumbent hairs.

Color. Body mostly black; clypeus antenna, legs, and gaster brownish to brownish lighter posteriorly.

Comments

In the workers, the clypeal median lobe with 12 chaetae (= stout setae), relatively straightened mandible, and brightly ferruginous gaster are very distinct hallmarks for this species. This species will key without difficulties to couplet 5 in Lattke (2011), whereupon the reader may use the modification to that key provided below. Leptogenys elzasoares new species is very similar in appearance to L. bohlsi , including the long and slender mandible but differs in the more straightened mandibles, slightly longer scape, and longer petiolar tooth. But the most distinctive characteristic is the clypeal median lobe with 12 chaetae in L. elzasoares new species, but in L. bohlsi usually only 3–4 chaetae are present. Although the workers of these two species are similar, the males can be distinguished by the enlarged compound eye in L. elzasoares new species male, with the distance between them slightly more than one eye length in full-face view, while it is relatively small in L. bohlsi males.

The male of L. elzasoares new species resembles L. unistimulosa ( Lattke, 2011) due to the large and bulging eyes, but can be easily differentiated by the petiole. TheL. elzasoares new species male has the petiolar summit truncate, while in L. unistimulosa the petiole summit is rounded to subtriangular. Another aspect to take into account is the shorter scape length in L. elzasoares new species (0.36 mm) than in L. unistimulosa (0.50–0.60mm).Differing colors may also help to separate these males: in L. elzasoares new species the body is mostly dark and the gaster is black to brownish posteriorly, while in L. unistimulosa the body is usually bicolored, the head and mesosoma mostly black to brown and the gaster ferruginous brown.The collection permit covering this collection event is SISBIO no. 53954, issued on 08 May, 2016.

Biology

The workers and male were collected walking on a trail in a small open area surrounded by primary Amazon Forest. Presumably these ants were either migrating at the time, or perhaps fleeing from an army ant raid. A phoretic deutonymph mite of the family Acaridae is adhered on the left maxillae of one worker (UFV-LABECOL-010408) ( Figure 7 ).

Etymology

This species is named, in apposition, after Elza da Conceição Soares (1930–2022), one of the greatest Brazilian singers of all time. Named the voice of the millennium, she was a powerful voice for social and racial justice, and women’s rights. Our beloved Elza has gone to rest, but her voice will forever echo in our hearts.

Material studied

Holotype: Brazil. Amazonas: Manaus, Colosso camp, 12-21.VIII.2016, Boudinot, B; Fernandes, I.; Chaul, J. Camp at -2.403723, -59.865735, 1 worker INPA - HYM 034449, [ INPA ]. Paratypes: same data as holotype, except 1 callow worker UFV-LABECOL-009566, [ CELC]; 1 worker UFV- LABECOL-010408; and 1 male UFV-LABECOL-011120, [ DZUP]; Manaus, Col. St. Antonio, 11.xi.1971, INPA #1 6564, 1 worker, [ MZSP].

Figures

Figure 4. Leptogenys elzasoares new species worker,INPA - HYM 034449 Holotype:(A) full-face,(B) lateral,(C) clypeus in full-face,(D) mesosoma,(E) petiole and (D) dorsal views.

Figure 5. Leptogenys elzasoares new species male, UFV-LABECOL-011120 paratype: (A) full-face, (B) lateral, mesosoma in (C) profile and (D) dorsal views, (E) fore wing and (F) hind wing.

Figure 6. Leptogenys elzasoares new species male genitalia,UFV-LABECOL-011120 paratype:(A) genital capsule in dorsal,(B) ventral and (C) lateral views,(D) abdominal sternum IX in vental view, (E) penisvalvae, (F) tergum IX, (G) gonopod and volsella in lateral views. Scale bar = 0.1 mm. go: gonopod, pe: penisvalvae, vo: volsella.

Figure 7. A phoretic deutonymph mite (Acaridae) on a L. elzasoares new species worker, paratype UFV-LABECOL-010408: (A) mite in situ on the left maxilla (white arrow); (B) mite ventral view and (C) zoom of left anterior legs.ce: compound eye, lb: labrum, md: mandible, mx: maxilla, sc: scape.