Gnamptogenys latistriata, Camacho & Franco & Feitosa, 2020

Camacho, Gabriela P., Franco, Weslly & Feitosa, Rodrigo M., 2020, Additions to the taxonomy of Gnamptogenys Roger (Hymenoptera: Formicidae Ectatomminae) with an updated key to the New World species, Zootaxa 4747 (3), pp. 450-476 : 465-466

Gnamptogenys latistriata new species

( Figure 18 )

Holotype: BRAZIL: Bahia: Ilhéus / Repartimento , 09.viii.1999, Santos, J.R.M. col. (1 worker) [CPDC— DZUP549798].

Paratypes: BRAZIL: Bahia: Ilhéus / Repartimento, 09.viii.1999, Santos, J.R.M. col. (2 workers) [DZUP]; São José da Vitória , 15°34’2’’S, 39°20’39’’W, 22.v.2000, Santos, J.R.M col. (3 workers) [MZSP] ; São José de Buerarema , 15°03’06’’S, 39°18’48’’W, 14.ix.2000, Santos, J.R.M. col. (2 workers) [CPDC—DZUP549799]

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Diagnosis: Medium size (TL 3.75−4.75). Scape surpassing the vertex margin by at least two times the width of the scape apex ( Fig. 18A ). Vertex margin straight. Compact mesosoma, with a slight metanotal impression; mesonotal dorsum not higher than propodeal dorsum in lateral view. Propodeal spiracle located directly on the declivitous face of propodeum margin ( Fig. 18C ). Mesosoma covered by wide costulae, at least 0.03 mm wide. Five longitudinal costulae on the dorsal surface of mesosoma ( Fig. 18B ). Petiolar node posteriorly inclined ( Fig. 18C ).

Description

Worker: HL 0.86−1.05; HW 0.69−0.85; ML 0.39−0.51; SL 0.80−1.05; EL 0.13−0.19; WL 1.15−1.44; PL 0.30−0.46; GL 1.03−1.29; TL 3.75−4.75; CI 79.71−82.86; SI 114.04−123.03; OI 16.05−22.06 (n=8). Reddish to reddish-brown, with lighter appendages, coppery. Body predominantly covered by thin, long and medium, erect and suberect hairs. Scape covered by many decumbent hairs and some medium suberect hairs.

Mandible striated on its dorsal face. Head dorsum covered with long, slightly irregular longitudinal costulae, semiparallel from the anterior margin of clypeus to the occipital margin of the head; head costulae wider than in other species of the genus, at least 0.03 mm wide; wide intervals between costulae, at least 0.0125mm. Mesosoma glossy and completely covered by wide costulae with a width ranging from 0.03 to 0.06 mm and slightly irregular margins. Pronotum with transverse costulae anteriorly and subparallel costulae on the dorsal surface. Dorsal surface of mesonotum, metanotum and propodeum with semiparallel and longitudinal costulae. Declivitous face of propodeum with longitudinal costulae throughout its length. Coxae always covered by transverse costulae; on procoxae, costulae not as wide as on mesosoma and head. Petiole with sculpture similar to mesosoma, very wide, concentric in dorsal view. Segments I and II of gaster entirely covered by longitudinal costulae, not as wide as the rest of the body. First gastral segment without transverse costulae on anterior face.

Mandible triangular. Anterior margin of clypeus strongly convex, giving it a rounded shape in frontal view. Clypeal lamella prominent, translucent and extending across the entire width of the anterior margin. Lateral margins of the head straight and subparallel. Antennal scape narrow, slightly wider apically, surpassing vertex margin by about one fifth of its length. Well-developed compound eyes, rounded and convex, located just behind the anterior half of the head in frontal view and with about seven ommatidia at larger diameter. Vertex margin straight; occipital corners prominent and rounded in lateral view.

Mesosoma compact, with a slight metanotal impression, but with mesonotal dorsum at the same level as propodeal dorsum in lateral view. Propodeal spiracle elevated above the sculpture, with very narrow opening; propodeal spiracle located directly on the margin of declivitous face of propodeum. Propodeum without spines or projections. Metacoxa with conspicuous spine.

In lateral view, posterior margin of petiole slightly concave; dorsal margin of petiole slightly convex; petiole not pedunculated. Subpetiolar process predominantly opaque, subquadrate and large, occupying nearly half of ventral surface of the petiole; subpetiolar process with a fenestra next to its posterior limit. Prora very prominent, V-shaped; its central angle with a keel; angled lateral margins in ventral view.

Etymology: From Latin: latus =wide and striatus =striated, referring to the wide costulae on the dorsal surface of the mesosoma. The species name is a feminine adjective in the nominative singular.

Distribution: All known specimens for Brazil have so far been collected in the coastal region of Bahia ( Fig. 17 ).

Natural History: There are no data on the biology of this species, since there is no additional information associated with the labels.

Comments: The width and number of costulae on mesosoma and the propodeal spiracle positioned at the lateral margins of the propodeum are enough to distinguish Gnamptogenys latistriata from any other of its closely related species. The species is very similar to G. strigata , a commonly collected species of wet montane transandean forests, that occurs throughout Central America, from Mexico to Colombia. Although Antmaps.org ( Janicki et al. 2016) lists Kempf (1972) as a reference for the occurrence of G. strigata in Brazil and Paraguay, Kempf (1972) does not record the species for those countries. G. strigata was not found to occur in Brazil during this revision or previous revisions ( Brown 1958; Lattke 1995). Gnamptogenys latistriata differs from G. strigata by its flat vertex margin and propodeum dorsum not depressed in relation to mesonotal dorsum. Aside from these differences and to the great geographic distance between the records of both forms, phylogenomic analysis revealed that G. latistriata represents a distinct lineage within Gnamptogenys , not closely related to G. strigata (Camacho et al., in prep).

Figures

FIGURE 17. Distribution records of the new and revived species of Gnamptogenys.

FIGURE 18. Holotype worker of Gnamptogenys latistriata (DZUP549798) in A) frontal view; B) dorsal view; and C) lateral view.