Ant Course 2018 was held in August at Nouragues Research Station (4.08796°N, 52.68002°W) in the Natural Reserve of Nouragues in French Guiana (Figs 1, 2). A French overseas territory on the northeastern edge of South America, French Guiana sits on a Precambrian massif known as the Guiana Shield (Grimaldi and Riéra 2001). The Nouragues station’s hilly landscape features a granitic inselberg that rises to 430 m (Fig. 2C, E; Grimaldi and Riéra 2001). The station lies in the Guianan Lowland Moist Forests ecoregion, a subset of the Tropical and Subtropical Moist Forests biome (Dinerstein et al. 2017); the climate is equatorial humid, and seasonality is determined by the movements of the Inter-tropical Convergence Zone (Grimaldi and Riéra 2001). The region experiences an average annual temperature of ~26 °C and yearly average precipitation ~2990 mm, with the rainy season occurring from November to August but interrupted in March by a short dry period (Grimaldi and Riéra 2001).

Figure 1. 

Shaded relief maps of the type locality of Corrieopone nouragues. Clockwise from top-left: South America, French Guiana, and Natural Reserve of Nouragues. Symbols: red circle, collection locality; circle with white fill and black outline, Cayenne, the capital of French Guiana.

Figure 2. 

Images of the Nouragues Research Station A ant Course 2018 students working in the lab at the Inselberg camp B view of the Inselberg camp kitchen facilities C forested landscape of the reserve viewed from the Nouragues Inselberg D rainforest along the Approuague river E the Nouragues Inselberg (top left of the image) and surrounding landscape F collection site of Corrieopone nouragues. Photography by BL Fisher.

During this study, we contrasted the morphology of the new genus with 129 species or subspecies representing all 47 currently valid extant Ponerinae genera (AntCat 2021; see Table 1 for taxa list, Suppl. material 1: Table S1 for specimen data). Suppl. material 3: Table S3 (character matrix) documents characters evaluated that could be unambiguously discretized, and we share it here to disclose our methodology and foster validation, replication, and reinterpretation of our results (see also Suppl. material 2: Table S2 for character statements).

Specimens were examined with a Leica M125 microscope with 187.5 × total magnification power (Leica Microsystems, Switzerland). Minute characters were accessed with scanning electron microscopy (SEM) or through SEM images previously available on AntWeb (www.antweb.org). Each specimen evaluated bears a registered unique identifier (e.g., CASENT0830464) associated with collection and specimen information, images, and identification on AntWeb. Data is accessible on AntWeb through the persistent URL of a given unique identifier (e.g., www.antweb.org/specimen/CASENT0830464).

Maxillary and labial palpal counts are based on direct observation of specimens with protracted maxillolabial complex (N = 41), dissections (N = 47), and existing SEM images of the maxillolabial complex on AntWeb.org (N = 26). For dissected specimens, the maxillolabial complex was removed from the buccal cavity with a pin or forceps. Larger specimens were observed with a Leica M125 microscope; smaller specimens were accessed with SEM. See Suppl. material 3: Table S3 (column Notes_char_9) for specimen data on palps evaluated, including unique specimen identifiers and observation method.

In subsequent sections, we refer to several other species whose morphology was only assessed through extended-focus images of specimens databased on AntWeb. Those species were not included in Table 1 or Tables S1 and S3. Instead, and when necessary, references are accompanied by the unique identifier of relevant specimens, which are hyperlinked to respective webpages on AntWeb.

Extended focus montage images were acquired with a Leica DFC 425 camera and LEICA APPLICATION SUITE software (version 3.8; Leica Microsystems, Switzerland). For most SEM images, samples were coated with gold-palladium in a Cressington 108 Sputter Coater (Cressington Scientific Instruments, United Kingdom), and micrographs were taken at high vacuum secondary electron emission (accelerating voltage: 15 kV, spot intensity diameter: 40) in a Hitachi SU3500 microscope (Hitachi High-Technologies, Japan). Uncoated specimens (e.g., primary types, unique specimens) were also imaged at high vacuum secondary electron emission, but with the accelerating voltage set to 1.5 kV and spot intensity to 50. Image enhancement (e.g., contrast, levels, sharpness, darken background) occurred in ADOBE PHOTOSHOP (version 22.4.2; Adobe Inc., United States of America). All images produced in this study are available on AntWeb.

Line drawings were originally traced in ADOBE ILLUSTRATOR (version 25.2.3; Adobe Inc., United States of America) or modified from artwork produced by scientific illustrator Jessica Huppi, whose authorship is credited in figure captions when pertinent. Jessica Huppi line art is part of a work-for-hire agreement that makes the California Academy of Sciences a copyright holder for her artwork.

Mapping of the study area occurred on RStudio Desktop (version 1.4.1717; RStudio Team 2021), an integrated development environment for R (version 4.1.0; R Core Team 2021). Spatial data was sourced directly from the following: NASADEM HGT v001 products (NASA JPL 2020), Global Lakes and Wetlands Database (GLWD-2 dataset; Lehner and Döll 2004), Shuttle Radar Topography Mission Water Body models (NASA JPL 2013), Global River Classification dataset (GloRiC version 1.0, Ouellet Dallaire et al. 2018), and Global Tree Cover dataset (Hansen et al. 2013). Alternatively, data were acquired and imported into R with functions of the following R packages: OSMDATA (Padgham et al. 2017), RASTER (Hijmans 2021), RWORLDMAP (South 2011), and RWORLDXTRA (South 2012); the OSMDATA package imports features from OpenStreetMap (OpenStreetMap.org data were available under the Open Database License). Data geoprocessing was executed with functions of DPLYR (Wickham et al. 2021), GDALUTILS (Greenberg and Mattiuzzi 2020), RASTER, and SF (Pebesma 2018) packages. Map projection and mapping were performed with functions available in the TMAP package (Tennekes 2018).

Positional and directional terminology references a hypothetical worker seen in profile, with the head oriented to the left and standing with legs slightly spread over the horizontal plane of a multidimensional space (Fig. 3). Mouthparts are retracted, and antennal scapes are directed posteriad, parallel to the head dorsum. We defined three main directional axes from this orientation, which guided the description of direction and relative position of morphological characters in this study. The anteroposterior axis extends horizontally across the space, from the anterior left side to the posterior right; the dorsoventral axis extends vertically, with “dorsal” directed upwards and “ventral” directed downwards. Finally, the mediolateral axis is perpendicular to a median plane that bisects the ant through its bilateral line, with “medial” directed towards the plane and "lateral" diverging from it (Fig. 3).

Figure 3. 

Anatomical position and coordinate system adopted as framework for positional and directional terminology. Corrieopone nouragues is shown in profile, with the head oriented to the left. The coordinate system is defined by the median plane and three directional axes (anteroposterior, dorsoventral, and mediolateral). Illustration by FA Esteves.

Additionally, we utilized a fourth axis for aiding the description of positions and directions of characters located on appendages, sclerites, processes, or any structure that may project away from the body. The basoapical axis arises from the median plane, with “basal” being close to the plane while “apical” is distant from it (Fig. 4A). Morphological terminology is based on Keller (2011) unless otherwise stated. Wherever possible, terms in the glossary are hyperlinked to correspondent terms in the Hymenoptera Anatomy Ontology portal (Yoder et al. 2010). Terms absent from the glossary below are defined, illustrated, or associated with references to pertinent literature at first use.

Anepisternum (an, Fig. 5B): Dorsal subdivision of the mesopleuron, separated from the katepisternum by the mesepisternal sulcus (= anapleural sulcus in Fisher and Bolton 2016).

Antenna (pl antennae; ant, Fig. 6A): Paired head appendage that, from base to apex, is composed of scape, pedicel, and flagellum. We refer to pedicel and flagellomeres as antennomeres; Roman numerals in ascending order indicate the position of individual antennomeres along the antenna’s basoapical axis (e.g., scape = antennomere I, pedicel = antennomere II, basalmost flagellomere = antennomere III).

Arolium (pl arolia; ar, Fig. 4B): The adhesive pretarsal organ; a soft cuticular structure between the pretarsal claws.

Bulbus neck: The constricted portion of the antennal scape, bordered basally by the bulbus (= condylar bulbus in Fisher and Bolton 2016) and apically by the main shaft of the scape.

Figure 4. 

Glossary of terminology, part I A hypothetical hindleg in a three-dimensional coordinate system defined by the anteroposterior, dorsoventral, and basoapical directional axes B apicalmost tarsomere and pretarsus in ventroapical view, with the retracted arolium highlighted in orange C probasitarsus and protibial apex in posterior view, with the comb of strigil highlighted in orange. Abbreviations: ar, arolium; bt, basitarsus; ca, calcar of strigil; cx, coxa; cw, claw; fm, femur; ma, manubrium; sgc, comb of strigil; tb, tibia; t1–5, tarsi; tch, trochanter. Illustrations by FA Esteves.

Calcar of strigil (ca, Fig. 4C): The protibial spur; together with the comb of strigil, forms the antennal cleaning organ.

Comb of strigil (sgc, Fig. 4C): Comb-like structure on the ventral face of the basal portion of the probasitarsus; together with the calcar of strigil, forms the antennal cleaning organ.

Epistomal sulcus (es, Fig. 6A, B; as in Richards 1977): Sulcus delimitating the clypeus posteriorly and laterally from the remainder of the head.

Galea (ga, Fig. 6E): The spatulate lobe located at the apical part of the stipes; part of the maxilla.

Galeal comb: Row of setae located on the outer face of the medial margin of the galea, opposite the maxillary comb located near the inner face of the margin.

Galeal crown: The apicalmost part of the galea.

Figure 5. 

Glossary of terminology, part II A body in profile, with the abdomen highlighted in orange hatching B mesosoma and petiole in profile, with the mesopleuron highlighted in orange hatching; laterotergite in solid orange C gaster in profile, with the hypopygium highlighted in orange D ventral face of the petiole; laterotergite highlighted in orange E dorsal face of the gaster. Abbreviations: A1–7, abdominal segments; an, anepisternum; cx1–3, coxae; he, helcium; hy, hypopygium; kn, katepisternum; lt, laterotergite; mn, mesonotum; mtp, metapleuron; mts, metanotal sulcus; nps, notopleural suture; pn, pronotum; ppd, propodeum; ppz, petiolar proprioceptor zone; pr, prora; pst, petiolar sternite; pstg, posttergite; pt, petiole; ptg, pretergite; py, pygidium; sp, subpetiolar process; spl, spiracular lobe; str, stridulitrum. Illustrations by FA Esteves.

Gaster (Fig. 5A, C, E; as in Fisher and Bolton 2016): Tagma formed by the third, fourth, fifth, sixth, and seventh abdominal segments in female ponerines. When mentioning individual segments, we refer to the homologous abdominal segment labeled by a corresponding Roman numeral (e.g., abdominal segment V). For aesthetic reasons in figures and measurements abbreviations, segments are noted by “A” followed by the corresponding Arabic numeral (e.g., A5).

Figure 6. 

Glossary of terminology, part III A head in full-face view B head in lateral view C mandibles and the anterior area of the clypeus in dorsal view D labrum and retracted maxillolabial complex in ventral view E maxillolabial complex in central view; labial palps highlighted in green, maxillary palps in orange. Abbreviations: ant, antenna; bm, basal margin of the mandible; cl, clypeus; es, epistomal sulcus; ga, galea; gl, glossa; lbr, labrum; lm, lateral margin of the mandible; md, mandible; mm, masticatory margin of the mandible; plb, labial palps; pm, premental shield; pmx, maxillary palps; sc, scape; st, stipes; tol, torular lobe; trm, torular median arch. Illustrations by FA Esteves (A, B, C, E), and modified from artwork by Jessica Huppi (D).

Helcium (he, Fig. 5C): Structure formed by the specialized presclerites of abdominal segment III, which articulates with the petiole.

Hypopygium (hy, Fig. 5C): The sternite of abdominal segment VII in adult female ants.

Katepisternum (kn, Fig. 5B): Ventral subdivision of the mesopleuron, separated from the anepisternum by the mesepisternal sulcus (= anapleural sulcus in Fisher and Bolton 2016). Note that this usage does not claim homology between the katepisternum in ants and homonymous mesothoracic areas in other insects.

Labrum (lbr, Fig. 6D): Mouthpart appendage that connects to the anterior margin, or the ventral face of the clypeus, and usually folds over the retracted maxillolabial complex.

Labial palps (plb, Fig. 6E): Labial ring-shaped sclerites articulated with the apicolateral portion of the prementum. We refer to each sclerite as a palpomere and use Roman numerals in ascending order to indicate the position of individual palpomeres along the basoapical axis of the palps (e.g., basalmost labial palpomere = labial palpomere I).

Lower and upper metapleuron (as in Snodgrass 1910): Secondary division of the metapleuron into dorsal wing-bearing and ventral leg-bearing portions.

Maxillary palps (pmx, Fig. 6E): Ring-shaped sclerites articulated with the apicomedial or the apicalmost portion of the stipes in the maxilla. We refer to each sclerite as a palpomere and use Roman numerals in ascending order to indicate the position of individual palpomeres along the basoapical axis of the palps (e.g., basalmost maxillary palpomere = maxillary palpomere I).

Mesoscutellar-axillar complex (as in Gibson et al. 1998): In winged ants, the area of the mesonotum that comprises the mesoscutellum and axillae; located posteriad to the transscutal line.

Mesoscutum (as in Gibson et al. 1998): In winged ants, the region of the mesonotum anterior to the transscutal line and mesoscutellar-axillar complex, whose laterals usually bear parapsidal lines.

Mesometapleural suture (as in Fisher and Bolton 2016): Groove-like suture delimiting the mesopleuron from the metapleuron.

Mesonotum (Fig. 5A): The tergum of the mesothorax.

Mesopleuron (Fig. 5B; as in Fisher and Bolton 2016): Pleuron of the mesothorax; extends over the lateral and most of the ventral external surfaces of the second thoracic segment.

Mesosoma (Fig. 5A): Tagma formed by the three thoracic segments (pro-, meso-, and metathorax) plus the propodeum (abdominal segment I).

Mesosternal process (as in Fisher and Bolton 2016): The pair of cuticular projections surrounding the midline of the mesothorax’s ventral face, anterior to the mesocoxal cavities.

Metasternal process (as in Fisher and Bolton 2016): The pair of cuticular projections surrounding the midline of the metathorax’s ventral face, anterior to the metacoxal cavities.

Metanotum (mts, Fig. 5B): The tergum of the metathorax; reduced to a groove (Fig. 5B) or completely indistinct in Ponerinae workers.

Metapleuron (mtp, Fig. 5B; as in Fisher and Bolton 2016): Pleuron of the metathorax; extends over the lateral and ventral external surfaces of the third thoracic segment; bears the metapleural gland opening laterally.

Notopleural suture (nps, Fig. 5B): Suture between mesopleuron and mesonotum.

Petiolar laterotergite (lt, Fig. 5B, D): Paired, long, narrow, strip-like area of the ventral margin of the petiolar tergite that is separated from the main part of the sclerite by an impression; flanks the petiolar sternite.

Petiolar proprioceptor zone (ppz, Fig. 5D): A depression on the anteriormost part of the petiolar sternite, sharply delineated anteriorly, and bearing numerous sensilla.

Petiole (pt, Fig. 5A, B, D): Abdominal segment II.

Postsclerite: Posterior portion of each abdominal sclerite not concealed by an articulation. The term posttergite refers to the postsclerite of a tergum (pstg, Fig. 5E), and poststernite to the postsclerite of a sternum (Fig. 5D).

Presclerite: Anterior articulatory region of each abdominal sclerite overlapped by the anterior segment. The term pretergite refers to the presclerite of a tergum (ptg, Fig. 5E), and presternite to the presclerite of a sternum.

Premental shield (pm, Fig. 6D, E): Labial sclerite that articulates apicolaterally with the labial palps.

Pronotum (pn, Fig. 5A): The tergum of the prothorax, which is hypertrophied in workers, and also in queens and males of some ant taxa.

Prora (pr, Fig. 5C; modified from Boudinot et al. 2020): Anteroventral process of abdominal sternite III that contacts the petiole sternite and gives stability to the ventral flexion of the gaster during stinging. It may be located anywhere from the area between the ventral margins of the helcial tergite arch to the anterior face of the poststernite.

Pygidium (py, Fig. 5A, C): In adult female ants, the tergite of abdominal segment VII.

Scape (sc, Fig. 6A): Basalmost antennomere followed apically by the pedicel; formed by the bulbus, the bulbus neck, and the main shaft of the scape.

Scutoscutellar sulcus (as in Gibson 1985): Sulcus impressed along the scutoscutellar suture. The scutoscutellar suture runs across the mesoscutellar-axillar complex, and separates axillae from mesoscutellum.

Stipes (st, Fig. 6D, E): Maxillary sclerite that articulates apically with the maxillary palps and with the galea.

Subpetiolar process (sp, Fig. 5B; as in Fisher and Bolton 2016): Ventral projection of the petiolar poststernite.

Suture and sulcus: A suture is a groove formed by the fusion of two sclerites; sulcus is an impression that corresponds to an apodeme.

Torular lobes (tol, Fig. 6A): Trait formed by the laterally projected median arches of the torulus; similar to frontal lobes.

Additionally, we used the following adjectives to describe vestiture:

Aristate: Shaped basally like a spine-like seta, and bearing a long, thin, flexuous apex.

Buoyant (Fig. 7A): Shaped as if floating in air and weightless.

Elliptic (Fig. 7B): Elongate oval, with the widest part near the middle.

Filiform (Fig. 7C): Filamentous, shaped like a thread. Here used to describe seta with a regular, hair-like shape.

Glabrous: Devoid of hair or cuticular projections.

Helicoid (Fig. 7D): Seta compressed longitudinally and twisted, resembling a helix.

Hook-shaped (Fig. 7E): Seta with the apical portion curved like a hook.

Lanceolate (Fig. 7F): Shaped like a lancehead, with the widest part near the base and the narrowest part near the apex.

Microtrichium (pl microtrichia; Fig. 7F, H, L): Setae-like, minute cuticular projection.

Serrate: With one margin bearing a series of small, sharp, teeth-like projections.

Spatulate (Fig. 7G, H): Shaped like a spatula, with a broad, flat apex that tapers to the base.

Spatulate-costate (Fig. 7I): Spatulate seta with longitudinal parallel ridges.

Spatulate-bicuspid (Fig. 7J): Spatulate seta in which the apex is much wider than the base, so that its apicolateral corners arch over the apicomedial area, giving the seta a bicuspid appearance.

Stout (Fig. 7K): Heavily built.

Tubiform (Fig. 7L): Tubular, not tapering to a point.

Sculpture terminology follows Harris (1979), as below.

Colliculate (Fig. 8A): Covered with continuous, short, rounded prominences.

Confused (Fig. 8E): Sculpture without definite outlines or definite pattern.

Costulate (Fig. 8B): With thin, longitudinal, parallel ridges.

Fossula (pl fossulae; Fig. 8C): Elongate, oblong depressions.

Punctate (Fig. 8D): With fine, impressed punctures.

Rugose (Fig. 8E): Wrinkled.

Smooth: Devoid of any sculpturing.

Strigate (Fig. 8F): With narrow, transverse ridges.

Strigulate (Fig. 8F): Finely or minutely strigate.

We utilized linear morphometry to quantify size and offer a means of comparison with other Ponerinae taxa. Measurements, indices, and abbreviations follow Fisher (2006). All measurements were taken at 80 × power with a Leica MZ125 microscope using an orthogonal pair of micrometers, recorded to the nearest 0.001 mm, rounded to two decimal places, and presented as minimum and maximum values with holotype measurement within parentheses. Indices are rounded to the nearest integer and expressed as minimum and maximum values with holotype index within parentheses (see original data in Suppl. material 4: Table S4).

Figure 7. 

Glossary of terminology, part IV: vestiture. Individual parts show SEM images taken from Corrieopone nouragues; paratypes, worker caste. Distinct types of seta and microtrichium are highlighted in orange A buoyant seta B elliptic seta C filiform seta D helicoid seta E hook-shaped seta F lanceolate microtrichium G spatulate seta H spatulate microtrichium I spatulate-costate seta J spatulate-bicuspid seta K stout, spine-like seta L tubiform microtrichium. Specimens imaged: CASENT0872031 (A, C, D, K) and CASENT0923158 (B, E–J, L). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.01 mm.

Figure 8. 

Glossary of terminology, part V: sculpture. Individual parts show SEM images taken from Corrieopone nouragues; holotype, worker (CASENT0830464) A rectangle encloses the colliculate sculpture on the metatibial apicoposterior surface B rectangle encloses the costulate lateral surface of the pronotum C arrows indicate the fossulae on the dorsal face of the mandible D punctate sculpture on the dorsoposterior area of the head E rectangle encloses the confused rugose sculpture on the petiolar profile F declivitous face of the propodeum and petiole in dorsal view; arrow indicates the strigulate sculpture; star highlights the strigate sculpture. Images by M Esposito (A, E) and FA Esteves (B–D, F); available at AntWeb.org. Scale bars: 0.1 mm (A, D); 0.2 mm (B, C, E, F).

HL Head length (Fig. 9A): Maximum longitudinal length of the head, measured from the anteriormost portion of the projecting clypeus to the midpoint of an imaginary line traced across the posterior margin of the head.

HW Head width (Fig. 9A): Maximum width of head, excluding eyes.

SL Scape length (Fig. 9A): Maximum chord length of the main shaft of the antennal scape, excluding basal bulbus and bulbus neck.

WL Weber’s length (Fig. 9B): With the mesosoma in profile, the diagonal length from the posteroventral corner of the propodeum to the farthest point on the anterior face of the pronotum (i.e., anterior inflection point of the pronotum), excluding the neck.

TL Total length: Sum of HL + WL + length of segments A2 to A7. A2 to A7 is measured as follows: maximum length of the petiole in profile (PL; Fig. 9B) + A3 to A7, or gaster length (GL; Fig. 9B).

CI Cephalic index: HW/HL × 100.

SI Scape index: SL/HW × 100.

Figure 9. 

Measurements taken from Corrieopone nouragues workers and queen A head in full-face view B body in profile. Abbreviations: GL, gaster length; HL, head length; HW, head width; PL, petiolar length; SL, scape length; WL, Weber’s length of mesosoma. Illustrations by FA Esteves.

CASC California Academy of Sciences, San Francisco, California, U.S.A.

JTLC John T. Longino private collection, Salt Lake City, Utah, U.S.A.

MHNG Musee d’Histoire Naturelle Genève, Geneva, Switzerland

MNHN Muséum Nationale d’Histoire Naturelle, Paris, France

MZSP Museu de Zoologia da Universidade de São Paulo, São Paulo, S.P., Brazil

Before describing Corrieopone nouragues gen. nov., sp. nov., we must make some adjustments to the taxonomic framework proposed for Ponerinae by Schmidt and Shattuck (2014), which otherwise would render comments on morphological similarities and differences among genera in subsequent sections cumbersome. The following changes are based on assessing female morphology among specimens examined in this study, with images available on AntWeb, and information gathered from relevant taxonomic literature.

Neoponera Emery and Pachycondyla Smith are recognized among other Neotropical ponerines by the following combination of characters: The anterior clypeal margin lacks a pair of large teeth-like projections. Torular lobes are closely approximated. Mandibles are triangular to subtriangular, inserted on the anterolateral corner of the head, and armed with numerous teeth. The metapleural gland orifice is closely skirted medially and posteriorly by a well-developed carina. The propodeal spiracle is usually slit-shaped; otherwise, the head presents a bilateral carina between the clypeal margin and the anterior margin of the compound eye, and the pretergite of abdominal segment IV presents a stridulitrum. The mesotibia lacks stout, spine-like setae along its dorsal face, and the metatibia presents two spurs. Pretarsal claws are not pectinate. The petiole sternite lacks a posterior spatulate projection that folds posteriad over the remaining sternite; otherwise, the anterior clypeal margin is convex and angulate (see Suppl. material 3: Table S3; Mackay and Mackay 2010; Schmidt and Shattuck 2014).

According to our assessment, Neoponera and Pachycondyla can be set apart from each other by only two characters: the former genus presents distinct arolia between the pretarsal claws and a stridulitrum on the pretergite of abdominal segment IV; the latter does not (see Suppl. material 3: Table S3; Kempf 1961a; Mackay and Mackay 2010; Fernandes et al. 2014; Schmidt and Shattuck 2014). Contrary to Schmidt and Shattuck (2014), the presence or absence of stout, spine-like setae on the posterior portion of the hypopygium is of little importance to distinguish the genera for two reasons. First, the hypopygium bears spine-like setae in some Neoponera species [e.g., N. bucki (Borgmeier), N. cavinodis, N. crenata, N. striadinodis, and N. unidentata; Fig. 10A, B], which are similar to those found in Pachycondyla (Fig. 10C, D). Second, in every Pachycondyla species examined (N = 6), some specimens presented a hypopygium armed with aristate setae instead (Fig. 10E). Moreover, among those aristate setae, a few had blunt-apices and resembled spines (Fig. 10F). We assume that this intraspecific and intraindividual shape variation is caused by wear. For example, contact with prey during stinging could erode the apices of pristine aristate setae on the hypopygium, which would then resemble spines.

Figure 10. 

Stout setae on the posterolateral face of the hypopygium in Neoponera and Pachycondyla A Neoponera bucki, worker (UFV-LABECOL-007493); hypopygium disassociated from the pygidium; arrows indicate the spine-like setae B N. carinulata, worker (CASENT0845443); arrow indicates the spine-like setae C Pachycondyla crassinoda, worker (CASENT0370917); arrow indicates the spine-like setae D P. harpax, worker (CASENT0374616); spine-like seta highlighted in orange E P. crassinoda, worker (CASENT0372235); left side; arrow indicates the aristate setae F P. crassinoda, worker (CASENT0372235); right side; arrow indicates the aristate setae; spine-like seta highlighted in orange. Images by JCM Chaul (A) and FA Esteves (B–F); available at AntWeb.org. Scale bars: 0.04 mm (A–C, E, F); 0.06 mm (D).

Other characters with inconsistent diagnostic value include the presence of a metanotal sulcus and the shape of the petiole. The metanotal sulcus is distinctly impressed in most Neoponera species, but is absent to shallowly marked or shows variation in distinctiveness in N. bucki (CASENT0915250), N. crenata species-group members (sensu Mackay and Mackay 2010; CASENT0923100), and N. laevigata (ATPFOR2006, CASENT0902510). In most Pachycondyla, the sulcus is obliterated, yet is present in some specimens of P. harpax (specimen CASENT0104808), P. impressa (ECOFOG-IT14-0276-06), P. lattkei (CASENT0217562), and P. striata (CASENT0178185, CASENT0249158). The shape of the petiole in profile ranges from scale-like to cuboid in Neoponera [as in N. carbonaria (Smith), CASENT0915655, and N. crenata, CASENT0915261, respectively]. It is cuboid in most Pachycondyla species, but also D-shaped in P. harpax (CASENT0249149) and scale-like in P. lenkoi Kempf (UFV-LABECOL-000002).

The Neotropical Pachycondyla procidua Emery, 1890 comb. rev. (Fig. 11) was previously assigned to Neoponera by Schmidt and Shattuck (2014). Yet, the species lacks a stridulitrum and distinct arolia (Fig. 12A, B; Kempf 1964). Additionally, it presents the above characters that discriminate Neoponera and Pachycondyla from ponerines in the neotropics (Fig. 11; Kempf 1964; Mackay and Mackay 2010). The metanotal sulcus is distinct (Fig. 11B), while the petiole is scale-like (Fig. 11C, D). The two specimens we examined present aristate hypopygial setae. The setae seem fragile, and in one specimen, most were abraded by the cleaning procedure that preceded SEM imaging (Fig. 12C, D).

Figure 11. 

Pachycondyla procidua comb. rev.; worker A head in full-face view (CASENT0646046) B dorsal view (CASENT0646046) C mesosoma in profile (CASENT0830573) D body in profile (CASENT0646046). Images by JT Longino (A, B, D) and FA Esteves (C); available at AntWeb.org. Scale bars: 1 mm.

Neoponera curiosa (Mackay & Mackay, 2010) comb. nov. also conforms with the characters shared by Neoponera and Pachycondyla (Fig. 13; Mackay and Mackay 2010). In addition, the species possesses a stridulitrum on the pretergite of abdominal segment IV (Mackay and Mackay 2010). According to the authors of the taxon, the arolia are underdeveloped. However, note that the adjective was likely used to compare the taxon with other species formerly assigned to Pachycondyla in which the arolium is distinct. For example, Mackay and Mackay (2010) also described the trait as underdeveloped in N. striadinodis; yet we examined one specimen determined by W. P. Mackay that has distinct arolia.

Figure 12. 

Pachycondyla procidua comb. rev.; worker (CASENT0830573) A median area of the abdominal pretergite IV in dorsal view B pretarsus and apex of apicalmost tarsomere in posterodorsal view C posterolateral face of the hypopygium D close-up of the posterolateral face of the hypopygium. Images by FA Esteves; available at AntWeb.org. Scale bars: 0.02 mm (A, B); 0.04 mm (C, D).

The genus Leptogenys Roger occurs in the tropics and subtropics around the world. Most of its species present pectinate or multidentate pretarsal claws, absent elsewhere in Ponerinae (Bolton 1975; Schmidt and Shattuck 2014; Fisher and Bolton 2016). The clypeal medial area usually projects anteriad into a well-developed, angular prominence, generally skirted anteriorly by a translucid lamella; the median area usually bears a longitudinal carina. Torular lobes are small and only conceal the medial portion of the antennal sockets in dorsal view. Mandibles insert on the anterolateral corners of the head. Mandible shapes range from subtriangular to oblique, to falcate, to linear, to bizarre forms in-between. The propodeal spiracle usually presents a round to oval orifice. The metatibia bears two spurs; the metabasitarsus does not bear stout, spine-like setae on its dorsal face. The helcium is infra-axial (i.e., helcium positioned ventrad to the midheight of the anterior face of abdominal segment III).

Figure 13. 

Neoponera curiosa comb. nov.; holotype, dealated queen (LACMENT226103) A head in full-face view B dorsal view C petiole in profile D body in profile. Images by JE Lattke; available at AntWeb.org. Scale bars: 0.5 mm.

The species originally described as Pseudoponera butteli Forel, 1913, based on specimens collected in Java, Indonesia, was recently assigned to the genus Euponera Forel by Schmidt and Shattuck (2014). However, the above characters setting Leptogenys apart from other ponerines are visible in images of its syntypes (Fig. 14; specimens CASENT0907293, FOCOL1012, FOCOL1013) or were mentioned in its description (Forel 1913), except for the shape of the pretarsal claws. On our behalf, entomologist and curator Dr B. Landry examined one of the syntypes deposited at the NHMG and confirmed the presence of three preapical teeth on the hindleg claws. Therefore, E. butteli becomes Leptogenys butteli (Forel, 1913) comb. nov.

Leptogenys butteli belongs to the L. processionalis species group (sensu Schmidt 2013), which contains ~15 taxa occurring in the Indomalayan and Australasian regions, viz.: L. birmana Forel, specimen CASENT0907581; L. breviceps Viehmeyer, CASENT0902610; L. crassicornis Emery, CASENT0903953; L. chelifera (Santschi), CASENT0915218; L. dentilobis Forel, CASENT0907365; L. fallax (Mayr), CASENT0915877; L. fortior Forel, CASENT0907393; L. iridescens (Smith), CASENT0901354; L. lucidula Emery, CASENT0235337; L. mutabilis (Smith), CASENT0901355; L. myops (Emery), CASENT0903952; L. processionalis (Jerdon), CASENT0270567; L. processionalis distinguenda (Emery), CASENT0903955; L. strena Zhou; and L. tricosa Taylor. Members of this species group are characterized by a quadrate or subquadrate head; oblique mandibles armed with more than three teeth, without distinct basal and masticatory margins (somewhat subtriangular in L. processionalis distinguenda); and scale-like petiole (somewhat nodiform in L. crassicornis, L. tricosa, and apparently also in L. strena).

Figure 14. 

Leptogenys butteli comb. nov.; syntypes, worker caste A head in full-face view (CASENT0907293) B dorsal view (CASENT0907293) C head in full-face view (FOCOL1013) D view in profile (CASENT0907293). Images by Z Lieberman (A, B, D) and C Klingenberg (C); available at AntWeb.org. Scale bars: 0.2 mm.

When we compared type specimen images and evaluated morphological variation among L. processionalis group members, we found several characters distinguishing between most species in the group. However, we could not find any significant differences between L. butteli and L. myops (Fig. 15). Their type specimens (all from Java, Indonesia) present the same head proportions and sculpture; shape of the torular lobes; shape of the clypeal anterior projection; width of the longitudinal protrusion on the clypeal median area; distance from the apex of the antennal scape to the posterior margin of the head; size, shape, and location of compound eyes on the head; sculpture and shape of the mandibles; dorsal outline of the mesosoma in profile; indistinctiveness of the metanotal sulcus; shape of the mesonotum in dorsal view; height of the petiole in comparison with the propodeum; shape of the petiolar tergite; body-color; and approximate length, amount, and inclination of standing setae. Consequently, we synonymize Leptogenys butteli (Forel, 1913), syn. nov., with Leptogenys myops (Emery, 1887).

Figure 15. 

Leptogenys myops; worker caste A head in full-face view; holotype (CASENT0903952) B dorsal view; holotype (CASENT0903952) C head in full-face view (CASENT0281925) D view in profile; holotype (CASENT0903952). Images by W Ericson (A, B, D) and S Hartman (C); available at AntWeb.org. Scale bars: 0.2 mm.

In the Afrotropics, the genera Bothroponera Mayr and Mesoponera Emery can be discriminated from other ponerines by a combination of characters in the worker caste (Fisher and Bolton 2016). The anterior portion of the head lacks a dorsolateral carina between the clypeal margin and the anterior margin of the eye. Torular lobes are closely approximated medially. The anterior margin of the eyes is located at or anteriad to the midlength of the head. Mandibles are triangular and inserted on the anterolateral corners of head; masticatory margins bear four or more teeth; basolateral or dorsal faces lack pits of any shape (an oblique dorsolateral sulcus may be present). The dorsoposterior area of the propodeum is devoid of spine-like or tooth-like projections. The mesotibia lacks stout spine-like setae on its dorsal face, and the metatibia bears two distinct spurs on its ventroapical face. The helcium is positioned ventrad the midlength of the anterior face of abdominal segment IV. Note that contrary to Schmidt and Shattuck (2014), only the basal portion of the masticatory margin of the mandibles is edentate in M. subiridescens; the apical portion is armed with four to seven, but sometimes more, teeth (the count includes denticles).

Bothroponera species have a propodeum with a broad dorsal face, a slit-shaped propodeal spiracle, and a nodiform petiole (Schmidt and Shattuck 2014). The metanotal sulcus is usually obliterated; however, intraspecific variation exists, and the sulcus is weakly impressed in some specimens [as B. ilgii (Forel), specimen CASENT0235600; and B. kruegeri (Forel), CASENT0235604]. Regardless, if present, the sulcus does not interrupt the dorsal outline of the mesosoma in profile. On abdominal segment IV, a strongly impressed constriction separates presclerites from postsclerites, as in B. berthoudi (Forel), specimen CASENT0902470; or moderately so, as in B. silvestrii CASENT0235599. Schmidt and Shattuck (2014) assigned Bothroponera species in two groups. The B. sensu stricto group members share a strongly sculptured body, hypertrophied torular lobes, and a metapleural gland orifice closely skirted medially and posteriorly by a well-developed carina; these characters are absent in the B. sulcata group. Notwithstanding the differential diagnosis given by the authors above, several species of the sensu stricto group [e.g., B. berthoudi, CASENT0902470; B. granosa (Roger), CASENT0250375; and B. laevissima (Arnold), CASENT0902471] have the propodeal dorsum as narrow as those of the sulcata group members.

In Mesoponera, the propodeum is tectiform (i.e., roof-shaped), with its lateral surfaces diverging while sloping ventrad from the noticeably narrow dorsum. In most species, the propodeal dorsal face presents slightly or moderately bulging lateral margins, with the medial area slightly concave posteriorly; the lateral margins may be somewhat parallel to one another (as in M. caffraria, CASENT0915251) or diverge continuously posteriad (as in M. ambigua, CASENT0249194). In a few species, the propodeal dorsum is narrower and transversely convex (as in M. subiridescens, CASENT0003151). The propodeal spiracle is usually round to oval [except for M. caffraria and subspecies, M. ingesta (Wheeler), and M. subiridescens; see CASENT0906219]. The petiole is shaped like an upward-pointing wedge in profile, with the anterior and posterior faces of the tergite tapering to a thin dorsal margin. The metanotal sulcus is clearly distinct and usually deeply impressed, and it indents the mesosoma outline in profile. The constriction between the presclerites and postsclerites of abdominal segment IV may be obliterated to moderately impressed. The torular lobes are not hypertrophied. Body is mostly smooth and shiny or densely and uniformly sculptured by fine punctures. These characters are as described here in every Mesoponera species except one.

The species originally described as Pachycondyla (Bothroponera) escherichi Forel, 1910, based on one worker collected in Eritrea (Fig. 16), was recently combined in Mesoponera by Schmidt and Shattuck (2014). However, the species is clearly misassigned. Mesoponera escherichi presents every character that sets Bothroponera and Mesoponera apart from the remaining Ponerinae genera in the Afrotropics, including the absence of a basolateral or dorsal pit on the mandibles (Forel 1910). The shape of the propodeal dorsal face corresponds to that of the B. sulcata group. The propodeal spiracle is slit-shaped. The petiolar tergite is unaligned in the image we evaluated; even so, it shows a somewhat nodiform petiole (clearly not cuneiform) that is reasonably accommodated by the variation seen in the Bothroponera. Moreover, Forel (1910) stated that the anterior and posterior faces of the petiole are vertical surfaces. The metanotal sulcus is present but weakly impressed, and does not interrupt the dorsal outline of the mesosoma in profile. The presclerites and postsclerites of abdominal segment IV are separated by a moderately impressed constriction. The torular lobes are not hypertrophied. Sculpture is not strongly impressed: most of the head and the dorsal face of the mesosoma is densely foveolate (i.e., covered by small pits that are wider than punctures); the lateral face of the mesosoma is mostly costulate; the petiole is somewhat shiny; the gaster is slightly punctate, and is shinier than the head and mesosoma. Therefore, M. escherichi becomes Bothroponera escherichi (Forel, 1910), comb. nov., a member of the B. sulcata species group.

Figure 16. 

Bothroponera escherichi comb. nov.; holotype, worker (CASENT0907252) A dorsal view B head in full-face view C view in profile. Images by W Ericson; available at AntWeb.org. Scale bars: 0.5 mm.

Figure 17. 

Identification key, couplet 1 A Odontomachus erythrocephalus, worker (CASENT0649085) AA Hypoponera aliena, worker (CASENT0281913). Images by JT Longino and S Hartman, respectively; available at AntWeb.org. Illustrations by Jessica Huppi.

We did not consider Pachycondyla vieirai Mackay & Mackay in this key, as it was not examined and the taxon description was uninformative for our purposes. The species was considered incertae sedis in Pachycondyla (Schmidt and Shattuck 2014).

Figure 18. 

Identification key, couplet 2 A, B Odontomachus meinerti, worker (CASENT0178690) AA BB Anochetus diegensis, worker (CASENT0178673). Images by A Nobile; available at AntWeb.org. Illustrations by Jessica Huppi.

Figure 19. 

Identification key, couplet 3 A, B Platythyrea angusta, worker (CASENT0907126) AA, BB Hypoponera aliena, worker (CASENT0281913). Images by W Ericson and S Hartman, respectively; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A, B), and by Jessica Huppi (AA, BB).

Figure 20. 

Identification key, couplet 4 A Platythyrea angusta, worker (CASENT0907126) AA Thaumatomyrmex zeteki, worker (CASENT0318451) B P. sinuata, worker (CASENT0217573) BB T. zeteki, worker (CASENT0318452). Images by W Ericson, M Esposito, W Ericson, and FA Esteves, respectively; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A), by FA Esteves (B), and Jessica Huppi (B, BB).

Figure 21. 

Identification key, couplet 5 A Simopelta paeminosa, worker (CASENT0217574) AA Dinoponera quadriceps, worker (CASENT0217519). Images by FA Esteves, available at AntWeb.org. Illustrations by Jessica Huppi.

Figure 22. 

Identification key, couplet 6 A Centromyrmex alfaroi, worker (ANTWEB1032026) AA Simopelta paeminosa, worker (CASENT0217574). Images by JCM Chaul and FA Esteves, respectively; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A), and by Jessica Huppi (AA).

Figure 23. 

Identification key, couplet 7 A, B left image: Simopelta paeminosa, paratype, worker (CASENT0902468); middle image: S. pergandei, holotype, worker (CASENT0907294) AA, BB Hypoponera alw06, worker (CASENT0173727) C S. paeminosa (CASENT0902468) CC Hypoponera vc01, worker (CASENT0766197). Images by W Ericson, Z Lieberman, A Nobile, and FA Esteves, respectively; available at AntWeb.org. Illustrations by FA Esteves (A, B), Jessica Huppi (AA, BB), and modified from artwork by Jessica Huppi (C, CC).

Figure 24. 

Identification key, couplet 8 A, B, C Ponera exotica, worker (CASENT0100692) AA Hypoponera vc01, worker (CASENT0766197) BB, CC H. parva (CASENT0260431). Images by FA Esteves (A, B, C, AA) and S Hartman (BB, CC); available at AntWeb.org. Illustrations by Jessica Huppi. Abbreviations: A2, abdominal segment II; A3, abdominal segment III.

Figure 25. 

Identification key, couplet 9 A Leptogenys pe02, worker (CASENT0372210) AA Dinoponera longipes, worker (CASENT0217518) B L. wheeleri, worker (CASENT0178811) BB D. longipes, worker (CASENT0004663). Images by FA Esteves (top two rows) and A Nobile (bottom two rows); available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A, B), by Jessica Huppi (AA), and FA Esteves (BB).

Figure 26. 

Identification key, couplet 10 A left image: Belonopelta attenuata, worker (ICN100255); middle image: B. deletrix, worker (CASENT0260514) AA Cryptopone cf. guatemalensis (CASENT0646802). Images by JT Longino (top and bottom left) and S Hartman (top middle); available at AntWeb.org. Illustrations by FA Esteves (A), and modified from artwork by Jessica Huppi (AA).

Figure 27. 

Identification key, couplet 11 A Cryptopone gilva, worker (CASENT0006054) AA Dinoponera quadriceps, worker (CASENT0217519) AAA Pseudoponera cognata, worker (CASENT0008155). Images by FA Esteves; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi.

Figure 28. 

Identification key, couplet 11 A Cryptopone gilva, worker (CASENT0260411) AA Pseudoponera gilberti, worker (CASENT0828638). Images by S Hartman and FA Esteves, respectively; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi. Abbreviations: A2, abdominal segment II; A3, abdominal segment III.

Figure 29. 

Identification key, couplet 12 A Dinoponera quadriceps, worker (CASENT0217519) AA Pachycondyla striata, worker (UFV-LABECOL-000291). Images by S Hartman and JT Longino, respectively; available at AntWeb.org. Illustrations by FA Esteves(A), and modified from artwork by Jessica Huppi (AA).

Figure 30. 

Identification key, couplet 13 A Rasopone panamensis, worker (CASENT0644252) AA Corrieopone nouragues, holotype, worker (CASENT0830464). Images by JT Longino and W Lee, respectively; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A), and by FA Esteves (AA). Abbreviations: A2, abdominal segment II; A3, abdominal segment III.

Figure 31. 

Identification key, couplet 14 A, B Corrieopone nouragues, holotype, worker (CASENT0830464) AA, BB Neoponera emiliae (JTLC000015100) C, D, E Corrieopone nouragues, paratypes, worker caste (CASENT0830465; CASENT0645962, insert) CC, DD, EE Neoponera fauveli, worker (CASENT0249142). Images by W Lee (A, B), JT Longino (AA, BB, E), FA Esteves (C, D), and R Perry (CC, DD, EE); available at AntWeb.org. Illustrations by FA Esteves (A–E), and modified from artwork by Jessica Huppi (AA–EE). Abbreviations: A3, abdominal segment III; A4, abdominal segment IV; A7, abdominal segment VII.

Figure 32. 

Identification key, couplet 15 A Neoponera fauveli, worker (CASENT0428712) AA Pachycondyla indet., worker (CASENT0006090). Images by FA Esteves; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi. Abbreviations: A2, abdominal segment II; A3, abdominal segment III; A4, abdominal segment IV.

Figure 33. 

Identification key, couplet 16 A Mayaponera constricta (CASENT0643470) AA Neoponera bugabensis (CASENT0217570) B M. constricta (CASENT0845824, left image; CASENT0643470, middle image) BB N. bugabensis (CASENT0217570, left and middle images). Images by FA Esteves (A, AA; B, BB, middle images), W Lee (B, left image), and W Ericson (BB, left image); available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi.

Figure 34. 

Identification key, couplet 17 A Pseudoponera stigma, worker (CASENT0922570) AA, BB Pachycondyla crassinoda, worker (CASENT0830390) B Pseudoponera gilberti, worker (CASENT0828638). Images by FA Esteves; available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi. Abbreviations: A2, abdominal segment II; A3, abdominal segment III.

Figure 35. 

Identification key, couplet 18 A Pachycondyla crassinoda, worker (CASENT0830390) AA Mayaponera conicula, paratype, worker (CASENT0923099) B P. striata, worker (CASENT0923096) BB M. pergandei, worker (CASENT0249156). Images by FA Esteves (A), W Lee (AA, B), and R Perry (BB); available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi.

Figure 36. 

Identification key, couplet 18 A Pachycondyla crassinoda, worker (CASENT0830390) AA Mayaponera conicula, paratype, worker (CASENT0923099); petiole disarticulated from gaster B P. lattkei, paratype, worker (CASENT0217562) BB M. cernua, worker (CASENT0923098). Images by FA Esteves (A, B, BB) and W Lee (AA); available at AntWeb.org. Illustrations modified from artwork by Jessica Huppi (A), by FA Esteves (AA), and Jessica Huppi (B, BB). Abbreviations: A3, abdominal segment III; A4, abdominal segment IV; A6, abdominal segment VI; A7, abdominal segment VII.

 Corrieopone , gen. nov.

http://zoobank.org/2B32773A-92E1-41B2-BC74-EC0B8ECD4A0A

Figs 7, 8, 37, 38, 39, 40, 41, 42, 43, 44, 52A, 53, 54, 55, 56, 57

Type species

Corrieopone nouragues sp. nov., by present designation.

Diagnosis based on workers

Medium-sized, slender Neotropical ants (TL 6.5–7.1 mm; Fig. 37) with characters of Ponerinae (as in Fisher and Bolton 2016) and Ponerini (as in Schmidt and Shattuck 2014), in addition to the following (asterisks indicate putative autapomorphies):

1. Mandibles triangular, with distinct masticatory and basal margins; inserted at the anterolateral corners of the head (Fig. 38A, E).

2. Mandibles edentate (Fig. 38A, E).

3. Mandible devoid of any pit or sulcus: basolateral and dorsal pits and dorsolateral and dorsomasticatory sulci absent (Fig. 38A–C, E).

4. * Clypeus complex: In dorsal view, clypeus projected anteromedially as a broad, truncated prominence, overhanging the basal margins of the mandibles, and overlapping the basal portion of the masticatory margins of fully closed mandibles; anterior margin of the clypeal projection approximately as wide as the distance between the lateral arches of the toruli, devoid of stout setae or additional protrusions (Figs 37B, 38A, E). In profile, clypeal projection with a broad anteroventral face (avf, Fig. 39A–D), which extends ventroposteriorly (i.e., obliquely) from the clypeal dorsal face in almost 90 degrees; the ventralmost point of this anteroventral face meets the “true” clypeal ventral face (= surface of the clypeal infold in Boudinot et al. 2021; vf, Fig. 39A–D). In anteroventral view, clypeal anteroventral face subrectangular (avf, Fig. 39D). Median area of the clypeus bulging (Fig. 37A, E); seen in profile, it ascends steeply from the clypeal anterior margin to the torular lobes, with posterior portion slightly convex (Fig. 38B, D).

5. In dorsal view, torular lobes closely approximated.

6. In dorsal view, torular lobes medium- to small-sized: not concealing the lateral arches of the toruli (Fig. 38F). Median and lateral arches of the torulus with discontinuous posterior margins (Fig. 38D).

7. In profile, torular lobes located at the dorsalmost part of a prominence formed by the clypeal median area and the frontal carinae (Fig. 38B).

8. Compound eyes small and located immediately anterior to the midline of the head (Fig. 38A, B, D).

9. Ocelli absent (Fig. 38A).

10. Labrum apically bilobed; with a long, acute cleft at the midpoint of its apical margin. Lobes broadly rounded apicolaterally and unarmed (Fig. 39E).

11. Palpal formula: 4,4 (four maxillary, four labial palpomeres; Fig. 39F).

12. Mesonotum rounded, dome-shaped in profile (Fig. 40A), rounded in dorsal view (Fig. 37A).

13. Notopleural suture distinct (Fig. 40A, B).

14. Metanotal sulcus deeply impressed (Fig. 40A).

Figure 37. 

Corrieopone nouragues, holotype, worker (CASENT0830464) A body in dorsal view B head in full-face view C body in profile. Images by W Lee; available at AntWeb.org.

15. Mesopleuron in profile divided into anepisternum and katepisternum (Fig. 40A, B).

16. Metathoracic spiracle concealed by a spiracular lobe (Fig. 40B).

17. Orifice of the metapleural gland round, opening posterolaterally on the metapleuron, with its ventral margin atop the posteriormost portion of the metapleural carina (Fig. 40C, D).

18. Metapleural longitudinal flange absent (Fig. 40C, D).

19. Propodeal dorsum devoid of a median longitudinal groove or impression.

20. Propodeum unarmed: without dorsoposterior projections (Fig. 40A).

21. In profile, propodeal lobe round, not surpassing posteriorly the dorsoposterior-most point of the rim of the propodeal foramen (Fig. 40C).

22. Propodeal spiracle slit-shaped (Fig. 40C).

Figure 38. 

Corrieopone nouragues, paratype, worker (CASENT0872031) A head in full-face view B head in profile; arrow indicates the torular lobes atop a prominence formed by the clypeal median area and the frontal carinae C dorsolateral face of the mandible D clypeus and torulus in profile; the arrowhead indicates the discontinuity between the posterior margins of the median and lateral arches of the torulus E dorsal face of clypeus and mandibles F torular lobes in dorsal view; the arrow points to the exposed lateral arch of the torulus. Images by FA Esteves; available at AntWeb.org. Scale bars: 0.5 mm (A, B); 0.3 mm (C, D, E, F).

23. Mesosternal process bidentate; metasternal process bilobate, long (Fig. 40F).

24. Metacoxal cavities open; cavities tightly encircled by cuticle, but cuticular annulus not fused (Fig. 40E; see comment in the following section).

25. Calcar of strigil with a basoventral lamella (Fig. 41A, B).

26. Probasitarsus with anterior and ventral faces densely vested with spatulate-costate setae (Fig. 41A), except for the shorter, spatulate-bicuspid setae present on the area immediately anterior to the comb of strigil (Fig. 41B).

27. Row of stout, spine-like setae present on the posterior face of the probasitarsal notch, parallel to the comb of strigil (Fig. 41B).

28. Two well-developed mesotibial spurs: anterior spur simple, posterior spur serrate (Fig. 41C, D).

Figure 39. 

Corrieopone nouragues, paratype, worker caste A clypeus in profile; mandible removed B anterior part of the head in oblique anterior view; mandibles and maxilla-labial complex removed C clypeus in oblique anterior view; mandibles and maxilla-labial complex removed D anterior part of the head in ventral view; mandibles and maxilla-labial complex removed E outer face of the labrum; basal towards the top of the image F outer face of the maxillolabial complex; basal towards the bottom of the image; Roman numerals indicate the count of maxillary and labial palpomeres. Specimens imaged: CASENT0923158 (E, F); CASENT0872031 (A–D). Images by FA Esteves; available at AntWeb.org. Abbreviations: avf, clypeal anteroventral face; df, clypeal dorsal face; vf, clypeal ventral face. Scale bars: 0.1 mm.

29. Apparent metatibial gland cuticular patch present on the apicoposterior face of the metatibia, next to the posterior metatibial spur (Fig. 41E).

30. Two well-developed metatibial spurs: anterior spur simple, posterior spur pectinate (Fig. 41F).

Figure 40. 

Corrieopone nouragues, paratypes, worker caste A mesosoma in profile B mesopleuron and part of metapleuron and propodeum in profile C katepisternum, metapleuron, and propodeum in profile D metapleural gland orifice in posterolateral view E metapleuron (and posterior part of the mesopleuron) in ventral view; arrowhead indicates the unfused annulus around the metacoxal cavity F mesosternal and metasternal processes in posterolateral view, highlighted by arrowhead and star, respectively. Specimens imaged: CASENT0872031 (A); CASENT0923158 (B–F). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.2 mm.

31. Stout, spine-like setae absent from the dorsal face of mid- and hindlegs (Fig. 42A, B).

32. Ventral faces of the second, third, and fourth tarsomeres of fore-, mid-, and hindlegs with a paired row of stout, spine-like setae skirting the midline of each segment (Fig. 42C–E).

Figure 41. 

Corrieopone nouragues, worker caste A protibia and protarsus in anterior view B protibial apex and probasitarsus in posteroventral view C mesotibial apex and basal portion of the mesobasitarsus in ventral view D mesotibial apex and basal portion of the mesobasitarsus in posterior view E metatibial apex in posterior view; note the lighter, colliculate cuticular patch next to the posterior metatibial spur F metatibial spurs in anterior view. Specimens imaged: holotype CASENT0830464 (E); paratype CASENT0923158 (A, C, D, F); paratype CASENT0872031 (B). Images by FA Esteves (A–D, F) and M Esposito (E); available at AntWeb.org. Scale bars: 0.1 mm.

33. Pro-, meso-, and metapretarsi with simple claws (Fig. 42C–F).

34. Arolia indistinct (Fig. 42F).

Figure 42. 

Corrieopone nouragues, paratypes, worker caste A midleg (minus coxa) in posterior view B hindleg (minus coxa) in anterior view C apex of the foreleg in anteroventral view D apex of the midleg in anteroventral view E apex of the hindleg in anteroventral view F apicalmost tarsomere and pretarsus of the foreleg in anteroventral view. Specimens imaged: CASENT0923158 (A–C, E, F); CASENT0872031 (B). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.1 mm.

35. Petiole sessile, with high, unarmed, conic, scale-like node (i.e., tergite narrow in profile and dorsal view; Figs 37A, C, 43A).

36. Petiolar tergite with anteroventral lateral carina (= lateral, dorsoventral carina in Ward 1990, character 29); posteroventral portion of tergite strigate (Fig. 43A).

Figure 43. 

Corrieopone nouragues, paratypes, worker caste A petiole in profile; arrowhead indicates the anteroventral lateral carina of the petiolar tergite B petiolar sternite in postlateroventral view; arrow indicates the proprioceptor zone on the anterior disc of the sternite C gaster in profile D helcium and prora in anterior view E the posterior portion of the abdominal tergite III and the anterior portion of the abdominal tergite IV in dorsal view; arrowhead indicates the stridulitrum F stridulitrum on abdominal pretergite IV. Specimens imaged: CASENT0923158 (A, B, D); CASENT0872031 (C, E, F). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.1 mm.

37. Petiolar laterotergite distinct (Fig. 43A).

38. Proprioceptor zone on anterior disc of petiolar sternite shaped as a large circular area (Fig. 43B).

39. Petiolar sternite without posterior spatulate projection (Fig. 43B); articulation with helcium visible in ventral view.

40. Helcium infra-axial: positioned ventrad the midheight of the anterior face of abdominal segment III (Fig. 43C).

41. Prora present as a lip-shaped, transverse projection on the anterior portion of the abdominal poststernite III (Fig. 43C, D); projection not extending anteriorly to the area between the ventroposterior margins of helcial tergite (Fig. 43D).

42. Abdominal segment IV tubular: tergite and sternite with similar lengths; tergite not arched (Fig. 43C).

43. Presclerites of abdominal segment IV forming an even surface with postsclerites: girdling constriction absent (Fig. 43C).

44. Stridulitrum present on abdominal pretergite IV, small (Fig. 43E, F).

45. Pygidium devoid of stout, spine-like setae or spine-like microtrichia; dorsal face convex.

46. * Ventral face of hypopygium longitudinally concave (Fig. 44A, B). Longitudinal carina present at midline of concavity’s posterior portion, skirted laterally by stout, hook-shaped setae (Fig. 44C, D).

Figure 44. 

Corrieopone nouragues, worker caste A the concave ventral face of the hypopygium armed with stout, hook-shaped setae (see arrowheads) on its posteriormost portion B hypopygium in ventrolateral view C close-up of the median carina (see arrowhead) and hook-shaped setae of the hypopygium in ventrolateral view D hook-shaped setae of the hypopygium in posteroventral view. Specimens imaged: holotype CASENT0830464 (A); paratype CASENT0923158 (B–D). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.1 mm.

47. Hypopygium posterolateral region without stout, spine-like setae or spine-like microtrichia.

Comments on worker characters

The enumeration below corresponds to character numbers presented above.

1. The mandibles articulate with the anterolateral corners of the head in virtually all Ponerinae and are either triangular or subtriangular in most genera (N = 29). Other mandibular shapes with little intrageneric variation are the oblique (Boloponera, Buniapone, Dinoponera, Iroponera, Plectroctena, and Promyopias), pitchfork-like (Belonopelta, Emeryopone, Thaumatomyrmex), elongate sub-oblique (Streblognathus), and scythe-shaped (Harpegnathos). The shape of the mandibles varies from triangular to elongate-triangular in Centromyrmex; from triangular to subtriangular, to oblique in Cryptopone; from subtriangular to oblique, to falcate, to bizarre forms in-between in Leptogenys and Myopias; from sub-oblique to falcate in Psalidomyrmex; and from subtriangular to oblique in Simopelta. Anochetus and Odontomachus are the only ponerines in which the mandibles insert near the midline of the anterior margin of the head.

2. The mandible of Corrieopone is completely edentate (i.e., devoid of any teeth, denticle, or projected apex). To our knowledge, this condition is virtually absent in other Ponerinae, apart from some species of Leptogenys (see Arimoto and Yamane 2018) and Platythyrea (see Fisher and Bolton 2016).

3. Ponerine may present mandibles ornamented with pits and sulci, which are relatively good diagnostic characters to genera.

3.1. The basolateral pit (= basal pit in Fisher and Bolton 2016) is a round to oblong impression on the basal portion of the lateral face of the mandible. It occurs in most Brachyponera species (excluding species from Borneo, Bali, Krakatau, and Sumatra, according to Yamane 2007), Cryptopone [except for C. guianensis and, based on its original description, C. mirabilis (Mackay & Mackay), as far as we know], and Euponera (see Schmidt and Shattuck 2014). The pit is also present in Fisheropone ambigua (Fig. 45A, B), which disagrees with Schmidt and Shattuck (2014) and Fisher and Bolton (2016).

3.2. The dorsal pit resembles the basolateral pit, although more elongated and impressed on the dorsal face of the mandible. In Ponerinae, it is only present in Dolioponera, Euponera fossigera Mayr (see Mayr 1901), Hagensia, and Iroponera (Fig. 45C; contrary to Schmidt and Shattuck 2014).

3.3. The dorsolateral sulcus runs obliquely along the mandible, from the basal portion of the dorsal face towards the lateral face. It is widespread among the Ponerinae and may be shallowly or deeply impressed, restricted to the basal portion of the mandible, or present along almost the entire lateral face of the mandible. The sulcus is consistently present in species of Asphinctopone, Boloponera, Buniapone, Centromyrmex, most (perhaps all) Ectomomyrmex, Feroponera, Loboponera, Myopias, Odontoponera, Paltothyreus, Phrynoponera, Plectroctena, Promyopias, Psalidomyrmex, Pseudoponera, and Streblognathus (see Suppl. material 3: Table S3; Schmidt and Shattuck 2014; Fisher and Bolton 2016). On the other hand, the presence of this character varies among species of other genera, such as Bothroponera (present in B. crassa, absent in B. pachyderma), Dinoponera (weakly present in D. lucida; absent in D. longipes), Leptogenys (see Bolton 1975), Mesoponera (only present in M. subiridescens), Neoponera [present in N. fauveli (Emery), weakly impressed in N. apicalis, absent in N. fisheri], Platythyrea (present in P. punctata, absent in P. turneri), and Pseudoneoponera (present in P. porcata, absent in P. denticulata). Contrary to Schmidt and Shattuck (2014), the sulcus is distinct in all Rasopone species examined here (Fig. 45D); although short and constrained to the basal region of the mandibles, it is also present in Austroponera castanea (Fig. 45E). Among the Pachycondyla species examined, the sulcus is a shallow and short basal impression save in P. lenis, where it is absent. In Euponera sikorae (and in all other Malagasy species, according to Rakotonirina and Fisher 2013), the lateral face of the mandible bears a longitudinal sulcus that runs apicad from the lateral margin of the dorsal mandibular articulation. Whether this sulcus is present in Euponera species occurring in other bioregions remains unknown, but it is absent in at least two Afrotropical species, E. brunoi and E. sjostedti.

Figure 45. 

A left mandible of Fisheropone ambigua in dorsal view; worker (CASENT0906209); arrow indicates the basolateral pit B left mandible of Fisheropone ambigua in postdorsolateral view (CASENT0906209); arrow indicates the basolateral pit C anterior part of the head of Iroponera odax in dorsal view; worker (ANTWEB1008537); arrow indicates the dorsal pit D head of Rasopone panamensis in profile; worker (CASENT0644543); arrow indicates the dorsolateral sulcus E anterior portion of the clypeus and posterior portion of the mandible of Austroponera castanea in dorsolateral view; worker (CASENT0097796); arrow indicates the short and shallow dorsolateral sulcus F the expanded maxillolabial complex of Dolioponera fustigera in ventral view; worker (CASENT0411307); Roman numerals indicate the count of maxillary and labial palpomeres G apical portion of the outer face of the left maxilla of Fisheropone ambigua (CASENT0906209); Roman numerals indicate the count of maxillary palpomeres H outer face of the labium of Fisheropone ambigua (CASENT0906209); Roman numerals indicate the count of labial palpomeres I apical portion of the outer face of the right maxilla of Loboponera obeliscata; worker (ANTWEB1008545); Roman numerals indicate the count of maxillary palpomeres J outer face of the labium and left maxilla of Loboponera obeliscata (ANTWEB1008545); Roman numerals indicate the count of labial palpomeres K apical portion of the outer face of the left maxilla of Boloponera ikemkha; paratype, ergatoid queen (CASENT0254321); Roman numerals indicate the count of maxillary palpomeres L outer face of the labium and right maxilla of Boloponera ikemkha (CASENT0254321); Roman numerals indicate the count of labial palpomeres. Images by FA Esteves (A, B, E–H, K, L), RA Keller (C, I, J), and JT Longino (D); available at AntWeb.org. Scale bars: 0.02 mm (A–C, F, G, I, J–L); 0.2 mm (D, E); 0.01 mm (H).

3.4. Plectroctena species present a sulcus that skirts the mandibular masticatory margin dorsally (Fisher and Bolton 2016), which we refer to as the dorsomasticatory sulcus.

Among the specimens examined, the following taxa present mandibles devoid of any pit or sulcus, like Corrieopone: Anochetus angolensis, A. emarginatus, Belonopelta deletrix, Bothroponera cariosa, B. pachyderma, B. talpa, Cryptopone guianensis, Diacamma ceylonense, Dinoponera longipes, Emeryopone buttelreepeni, Harpegnathos saltator, Hypoponera punctatissima, Mayaponera, Megaponera analis, Mesoponera ambigua, M. australis, M. caffraria, M. elisae rotundata, M. melanaria macra, M. papuana, M. rubra, Neoponera commutata, N. fisheri, N. laevigata, N. luteola, N. verenae, N. villosa, Odontomachus bauri, Ophthalmopone berthoudi, Pachycondyla lenis, Parvaponera darwinii madecassa, Platythyrea turneri, Ponera alpha, P. pennsylvanica, Simopelta oculata, S. transversa, Thaumatomyrmex fraxini, and T. zeteki.

6. We assessed the size of the torular lobes across taxa examined according to the degree of connection between median and lateral arches of torulus (as in Keller 2011, character 08). Among material examined, the lobes are anteriorly and posteriorly continuous with the lateral torular arches in taxa whose antennal sockets are largely exposed in full-face view (Belonopelta, Leptogenys, and Ophthalmopone). On the other extreme, hypertrophied lobes are anteriorly and posteriorly discontinuous with the lateral arches of the torulus (as in Boloponera, Bothroponera sensu stricto group, Loboponera, Platythyrea punctata, Plectroctena, and Psalidomyrmex). Like Corrieopone, most ponerines present intermediate-sized torular lobes that are anteriorly continuous and posteriorly discontinuous with respective lateral arches. In this latter state, the lobes may conceal entirely or partially the lateral arches of the torulus.

For the record, the torular lobes in Bothroponera sulcata species-group members (sensu Schmidt and Shattuck 2014) resemble those of Corrieopone, except for B. henryi (Donisthorpe) (see specimen CASENT0902482) and B. zumpti Santschi (see CASENT0922370), where the lobes are hypertrophied as in the Bothroponera sensu stricto group.

9. Ocelli are invariably present on Harpegnathos workers; it is absent in the worker caste of other Ponerinae, apart from occasional workers.

11. A count of four maxillary and four labial palpomeres is consistently present in Buniapone, Dinoponera, Hagensia, Harpegnathos, Mayaponera (note that we did not examine M. longidentata), Megaponera, Odontoponera, Ophthalmopone, Paltothyreus, Phrynoponera, Promyopias, Streblognathus (see Suppl. material 3: Table S3; Bolton 2003; Fisher and Bolton 2016). We are hesitant to affirm that this is also the case in Neoponera, Pachycondyla, Pseudoneoponera, and Rasopone. These characters usually have been neglected in taxonomic reviews and descriptions of new species, and we did not examine every species in these genera. Yet, in every species we did examine (Neoponera aenescens, N. apicalis, N. bugabensis, N. carinulata, N. commutata, N. crenata, N. curiosa, N. dismarginata, N. fisheri, N. foetida, N. globularia, N. insignis, N. inversa, N. laevigata, N. luteola, N. moesta, N. obscuricornis, N. schoedli, N. striadinodis, N. unidentata, N. verenae, N. villosa, Pachycondyla crassinoda, P. harpax, P. impressa, P. lattkei, P. lenis, P. procidua, P. striata, Pseudoneoponera porcata, P. tridentata, Rasopone costaricensis, R. cryptergates, R. cubitalis, R. guatemalensis, R. panamensis, R. pluviselva, and R. politognatha), the palpal formula was 4,4. The count is also 4,4 in some species of genera with variable palpal formulae, such as Anochetus, Bothroponera, Leptogenys, Mesoponera, and Myopias (see Suppl. material 3: Table S3; Willey and Brown 1983; Bolton 2003; Fisher and Bolton 2016).

While conducting this study, we noticed that the palpal formula of some taxa was incorrectly reported or missing in the pertinent literature. Thus we correct or update the record here. Contrary to Fisher and Bolton (2016), the palpal formula in Dolioponera fustigera is 3,3 (not 2,2, as previously stated; Fig. 45F), and 3,3 in Fisheropone ambigua (not 3,2; Fig. 45G, H). Contrary to Bolton (2003), Keller (2011), and Fisher and Bolton (2016), the palpal formula in Loboponera obeliscata is 2,3 (not 2,2; Fig. 45I, J); the formula in L. vigilans was correctly reported as 2,2 by these authors (verified on specimen CASENT0003102). We also report for the first time the palpal formula in Boloponera ikemkha (2,3; Fig. 45K, L), Cryptopone hartwigi (3,3; Fig. 46A, B), and Simopelta transversa (2,2; Fig. 46C). The specimen of Thaumatomyrmex atrox examined by Keller (2011) was later determined to be T. fraxini by D’Esquivel et al. (2017) – note that the specimen is not in the list of material examined by the latter authors, but some SEM images taken by Keller (2011; specimen ANTWEB1008597) were used to illustrate the new taxon description. One detail not mentioned by D’Esquivel et al. (2017) was the palpal formula of T. fraxini, which is 3,3 (Fig. 46D; previously reported for T. atrox by Keller 2011). Finally, although Fisher and Bolton (2016) stated that the palpal formula in Parvaponera darwinii madecassa is unknown, Brown (1963) provided the correct count, which is 4,3 (Fig. 46E).

12–14. In Corrieopone, the mesonotum is dome-shaped in profile, with a round dorsal margin that is discontinuous with the outline of the pronotum (i.e., it is slightly higher than the pronotum). The promesonotum is much higher than the propodeum, and a deeply impressed metanotal sulcus separates the two. A distinct notopleural suture delimits the mesonotum from the mesopleuron. In dorsal view, the mesonotum is round. Taxa that bear some resemblance to Corrieopone in this combination of characters are: several Anochetus species (e.g., A. altisquamis Mayr, specimen CASENT0915154; A. armstrongi McAreavey, CASENT0902449; A. brevis Brown, CASENT0902439), Asphinctopone, Austroponera [except A. rufonigra (Clark), CASENT0249178], Brachyponera, Euponera sikorae, Fisheropone ambigua, Hagensia, some Hypoponera [e.g., H. foreli (Mayr), CASENT0173714; H. herbertonensis (Forel), CASENT0907320; H. mesoponeroides (Radchenko), CASENT0917250], some Leptogenys (e.g., L. borivava Rakotonirina & Fisher, CASENT0430091; L. ixta, L. peruana, L. sonora), Mayaponera, Megaponera analis (dome-shaped mesonotum in larger specimens, as CASENT0781129), most Mesoponera (e.g., M. ambigua, M. australis, M. caffraria, M. elisae rotundata, M. melanaria, M. papuana, M. rubra, M. subiridescens), several Myopias [e.g., M. castaneicola (Donisthorpe), CASENT0902520; M. chapmani Willey & Brown, CASENT0902533; M. latinoda (Emery), CASENT0270592], several Neoponera (e.g., N. apicalis, N. aenescens, N. fisheri, N. schoedli, N. villosa), some Odontomachus (e.g., O. bauri; O. laticeps Roger, CASENT0904008; O. spissus Kempf, CASENT0281868), Odontoponera transversa, Ophthalmopone, Rasopone rupinicola, R. cubitalis, and Streblognathus.

16. The spiracular lobe is present in most ponerine genera; it is present in Boloponera ikemkha (CASENT0254321) and B. vicans (CASENT0401737), contrary to Fisher and Bolton (2016).

The lobe is absent in Dolioponera, Fisheropone, some Loboponera species, the Afrotropical and Malagasy Hypoponera, H. punctatissima, Simopelta oculata, S. transversa, and Thaumatomyrmex fraxini (Suppl. material 3: Table S3; Fisher and Bolton 2016). Interestingly, while the lobe is absent in the Afrotropical Cryptopone (according to Fisher and Bolton 2016; here confirmed on C. hartwigi), it is present in the Neotropical C. gilva (ANTWEB1008514), C. guianensis (ANTWEB1008565), C. holmgreni (ECOFOG-IT14-0276-07), and C. pauli (CASENT0637806).

18. The metapleural longitudinal flange is a carina that extends along the metapleuron in profile, with its posterior end immediately dorsad the metapleural gland orifice. When well-developed, it projects laterad or ventrolaterad and may overhang the gland orifice (as defined by Keller 2011: character 62). In Simopelta species (ANTWEB1008589), this flange is strongly projected ventrolaterad and overlaps the gland orifice.

19. The propodeal dorsum presents a well-delimited, narrow, median longitudinal groove in Psalidomyrmex (Fisher and Bolton 2016; ANTWEB1008585). In addition, a vestigial longitudinal groove may be present on the propodeal dorsal face of specimens of the Plectroctena minor group (see Bolton and Brown 2002). The propodeal dorsum is transversely concave along its entire length, or only posteriorly, in Hagensia, Mayaponera (CASENT0249137), several Mesoponera (CASENT0249194), and Pseudoponera (CASENT0923115).

20. Most ponerine genera present an unarmed propodeum. In profile, the propodeal dorsoposterior corner bears acute projections in several Anochetus species (e.g., CASENT0902431, CASENT0815182, CASENT0746783), Phrynoponera (CASENT0178230), Streblognathus (ANTWEB1008591), some Platythyrea (CASENT0281867, CASENT0900569, CASENT0903799), and Pseudoneoponera bispinosa (Smith). Also, some species of the Loboponera vigilans group (CASENT0003111), Plectroctena minor group (CASENT0915285), and P. mandibularis group (CASENT0102947) present the lateral margin of the propodeal declivity with a lamella that is dorsally toothed; in other species of the L. vigilans group, the lateral margin of the propodeal declivity is toothed dorsally, but the lamella is absent (CASENT0003098; see Bolton and Brown 2002).

Figure 46. 

A outer face of the left maxilla of Cryptopone hartwigi; worker (CASENT0251956); Roman numerals indicate the count of maxillary palpomeres B outer face of the labium of Cryptopone hartwigi (CASENT0251956); Roman numerals indicate the count of labial palpomeres C expanded maxillolabial complex of Simopelta transversa in ventral view; worker (ANTWEB1008589); Roman numerals indicate the count of maxillary and labial palpomeres D maxillolabial complex of Thaumatomyrmex fraxini in ventroapical view; worker (ANTWEB1008597); Roman numerals indicate the count of maxillary and labial palpomeres E expanded maxillolabial complex of Parvaponera darwinii madecassa in ventral view; worker (CASENT0389498); Roman numerals indicate the count of maxillary and labial palpomeres F right metacoxal cavity of Platythyrea cribrinodis in ventral view; worker (CASENT0778160); arrowhead indicates the fused annular cuticle encircling the cavity externally G right metacoxal cavity of Myopias darioi in ventral view; paratype, worker (CASENT0810080); arrowhead indicates the fused annular cuticle encircling the cavity externally H right metacoxal cavity of Phrynoponera pulchella in ventral view; worker (CASENT0217034); arrowhead indicates the annular gap around the cavity F protibial apex and basal region of the probasitarsus of Loboponera obeliscata in posterior view; worker (ANTWEB1008545); arrowhead indicates the minute basoventral lamella of the calcar. Images by FA Esteves (A, B, E–H) and RA Keller (C, D, I); available at AntWeb.org. Scale bars: 0.02 mm (A, B, D); 0.03 mm (C); 0.04 mm (E–I).

22. In general, the shape of the propodeal spiracle is constant within genus in Ponerinae. A slit-shaped spiracle (i.e., external atrial opening > 2 × longer than wide; as in Keller 2011, character 65) is present in Asphinctopone, Austroponera, Bothroponera, Buniapone, Corrieopone, Diacamma, Dinoponera, Ectomomyrmex, Euponera, Feroponera, Fisheropone, Hagensia, Harpegnathos, Megaponera, Odontoponera, Ophthalmopone, Pachycondyla, Paltothyreus, Phrynoponera, Pseudoneoponera, and Streblognathus. A round to oval spiracle occurs in Belonopelta, Boloponera, Dolioponera, Emeryopone, Hypoponera, Iroponera, Loboponera, Mayaponera, Myopias, Odontomachus, Plectroctena, Ponera, Promyopias, Psalidomyrmex, Rasopone, Simopelta, and Thaumatomyrmex. The propodeal spiracle is round to oval in most Brachyponera species but varies from oval to slit-shaped in B. atrata and B. sennaarensis.

24. We classified the metacoxal cavities as closed or open by integrating the definition given by Keller (2011: character 69) with that in Fisher and Bolton (2016; see also Bolton 2003: character 41). If closed, the medial surface of the metacoxal acetabulum does not have a fenestra, and thus, the metacoxal cavity is not connected internally with the propodeal foramen; the annulus externally encircling the cavity is fused. If open, the internal medial surface of the cavity is fenestrate and connects with the propodeal foramen, and the annulus is unfused. In this case, the annulus may encircle the cavity with its free ends overlapping next to the propodeal foramen; or there may be a gap in the annulus.

An unfused cuticular annulus tightly encircles the metacoxal cavities in most Ponerinae we dissected. This condition occurs in Phrynoponera pulchella specimens from Kenya (CASENT0178203, CASENT0178204, CASENT0217125), which is in accord with Bolton and Fisher (2008a). However, a specimen from Tanzania possesses an annular gap in both metacoxal cavities (Fig. 46H); we are uncertain if those were natural or dissection artifacts, as unfortunately, only one specimen from that population was available to us. Metacoxal cavities also present an annular gap in Phrynoponera transversa and Platythyrea punctata. On the other hand, the annulus is fused and uninterrupted in Harpegnathos saltator, Platythyrea cribrinodis (Fig. 46F; contrary to Fisher and Bolton 2016), and Myopias darioi (Fig. 46G).

25. The calcar of strigil presents a basoventral lamella in most Ponerinae evaluated (as in Keller 2011, character 74). For clarification, we consider the calcar to present a small lamella in Loboponera obeliscata (Fig. 46I) and that it is entirely pectinate in Platythyrea punctata and P. turneri (specimens ANTWEB1008574 and ANTWEB1008575, respectively), which is contrary to Keller (2011). The lamella is also absent in Boloponera, Brachyponera sennaarensis, Diacamma ceylonense, Dolioponera fustigera, Emeryopone buttelreepeni, Harpegnathos saltator, Hypoponera punctatissima, Leptogenys ixta, L. peruana, L. pucuna, L. sonora, L. wheeleri, Loboponera vigilans, Mesoponera ambigua, M. elisae rotundata, Myopias darioi, Platythyrea cribrinodis, Ponera alpha, P. pennsylvanica, Promyopias silvestrii, Simopelta oculata, S. transversa, Thaumatomyrmex fraxini, and T. zeteki.

27. A row of stout, spine-like setae occurs along the posterior face of probasitarsal notch, parallel to the comb of strigil, in most Ponerinae taxa examined. We adopted the definition of “row” analogous to that of a line, whose existence requires at least two points in space. Thus, the row is present if two or more spine-like setae are aligned longitudinally along the posterior face of the probasitarsal notch; less than two setae make the row absent. Among material examined, the row is absent on the posterior face of the probasitarsal notch in Dolioponera fustigera, Leptogenys, Myopias darioi, and Thaumatomyrmex fraxini.

28. Most Ponerinae taxa present two mesotibial spurs. Among taxa examined, the anterior spur is simple, and the posterior spur is serrate in Brachyponera chinensis, B. croceicornis, B. lutea, B. luteipes, B. obscurans, Dinoponera longipes, D. lucida, Hagensia havilandi marleyi, Harpegnathos saltator, Leptogenys peruana, L. pucuna, and Ophthalmopone berthoudi.

For the record, only one mesotibial spur is visible under a stereomicroscope in Asphinctopone silvestrii and Fisheropone ambigua; however, SEM images reveal that a vestigial anterior spur is present in both taxa (Fig. 47C, E); A. differens also seems to bear a minute anterior spur on the mesotibia.

29. The metatibial gland has been confirmed in Bothroponera tesseronoda (Emery), several species of Diacamma Mayr, Harpegnathos saltator, Neoponera crenata, N. marginata (Roger), Paltothyreus tarsatus, Pseudoneoponera rufipes (Jerdon), and P. tridentata (see Hölldobler et al. 1996; Billen 2009). The gland is associated with a cuticular pore plate, which may be covered by a brush of stouter, distinctly-shaped setae (as in Diacamma and Paltothyreus tarsatus), or it may be an oblong, glabrous, distinctly colored, smooth, or distinctly sculptured cuticular patch (Hölldobler et al. 1996). Here, we list taxa that present the latter condition, which is what is seen in Corrieopone. Among the taxa examined, the cuticular patch is present on the apicoposterior face of the metatibia in Bothroponera crassa, B. silvestrii, Brachyponera croceicornis, B. lutea, B. luteipes, B. obscurans, B. sennaarensis, Cryptopone hartwigi, Ectomomyrmex javanus, Emeryopone buttelreepeni, Euponera sikorae, E. sjostedti, Feroponera ferox, Hagensia havilandi marleyi, Mesoponera caffraria, Pseudoneoponera porcata, and P. tridentata.

30. Most Ponerinae taxa present two metatibial spurs. Here, all specimens examined present a pectinate posterior spur, and in the majority, the anterior spur is simple, as in Corrieopone (see Suppl. material 3: Table S3).

For the record, Schmidt and Shattuck (2014: 185) and Fernandes and Delabie (2019: 411) stated that Cryptopone species present one metatibial spur (excluding C. guianensis, and in the case of the latter authors, also C. pauli). Those assertions are puzzling, as several Cryptopone species have two spurs on the metatibia [e.g., C. arabica Collingwood & Agosti, C. gilva, C. holmgreni (Wheeler), C. ochracea Mayr; see Fig. 47A; Kempf 1961b; Bernard 1967; Collingwood and Agosti 1996]. Belonopelta deletrix has two spurs on the metatibia (Fig. 47B), as correctly stated by Baroni Urbani (1975), but contrary to Schmidt and Shattuck (2014). Asphinctopone silvestrii presents a minute additional metatibial spur (Fig. 47D), anterior to the much larger pectinate spur; A. differens seems to present the same. The metatibia of Fisheropone ambigua, which bears a single spur, long and pectinate, also presents a fovea where the anterior spur would be located (Fig. 47F).

Figure 47. 

A apex of the metatibia and basal region of the metabasitarsus of Cryptopone gilva in anterior view; worker (ANTWEB1008514); arrows highlight the metatibial spurs B apex of the metatibia and basal region of the metabasitarsus of Belonopelta deletrix in anterior view; worker (ANTWEB1008507); arrows highlight the metatibial spurs C ventroapical portion of the mesotibia of Asphinctopone silvestrii in anteroventral view; worker (CASENT0824505); arrows highlight the minute anterior and much larger posterior spurs D ventroapical portion of the metatibia of Asphinctopone silvestrii in anteroventral view (CASENT0824505); arrows highlight the minute anterior and much larger posterior spurs E ventroapical portion of the mesotibia of Fisheropone ambigua in ventral view; worker (CASENT0906216); arrows highlight the vestigial anterior and well-developed posterior spurs F ventroapical portion of the metatibia of Fisheropone ambigua in oblique anteroventral view (CASENT0906216); arrows highlight a fovea at the place the anterior spur would be located and the large posterior spur. Images by RA Keller (A, B) and FA Esteves (C–F); available at AntWeb.org. Scale bars: 0.03 mm (A, B); 0.004 mm (C–F).

31. Taxa without stout, spine-like setae on the dorsal face of the mid- and hindlegs are Anochetus angolensis, A. emarginatus, Asphinctopone differens, As. silvestrii, Belonopelta deletrix, Boloponera ikemkha, B. vicans, Bothroponera silvestrii, Brachyponera chinensis, B. croceicornis, B. luteipes, B. obscurans, B. sennaarensis, Diacamma ceylonense, Dolioponera fustigera, Emeryopone buttelreepeni, Euponera sikorae, E. sjostedti, Hagensia havilandi marleyi, Harpegnathos saltator, Iroponera odax, Leptogenys ixta, L. peruana, L. pucuna, L. sonora, L. wheeleri, Loboponera obeliscata, L. vigilans, Mayaponera conicula, Myopias darioi, M. maligna, Neoponera bugabensis, N. carinulata, N. cavinodis, N. crenata, N. dismarginata, N. fiebrigi cf., N. fisheri, N. foetida, N. globularia, N. insignis, N. inversa, N. luteola, N. moesta, N. obscuricornis, N. striadinodis, N. unidentata, N. villosa, Odontomachus bauri, Odontoponera transversa, Ophthalmopone berthoudi, Platythyrea cribrinodis, P. punctata, P. turneri, Simopelta oculata, S. transversa, Thaumatomyrmex fraxini, and T. zeteki.

Contrary to Fisher and Bolton (2016), Fisheropone ambigua presents stout, spine-like setae on the dorsal face of the mesobasitarsus (Fig. 48A).

33. We categorized the shape of pro-, meso-, and metapretarsal claws according to the presence, location, and number of acute projections on their inner margins (modified from Keller 2011, character 82). A simple pretarsal claw is devoid of prominences (Fig. 48B) or presents a blunt basal angle or rounded swell (Fig. 48C), and is found in the following taxa: Anochetus angolensis, A. emarginatus, Asphinctopone differens, A. silvestrii, Austroponera castanea, Belonopelta deletrix, Boloponera ikemkha, B. vicans, Bothroponera crassa, B. silvestrii, Brachyponera chinensis, B. croceicornis, B. lutea, B. luteipes, B. obscurans, B. sennaarensis, Centromyrmex brachycola, C. decessor, C. ereptor, C. raptor, Cryptopone gilva, C. guianensis, C. hartwigi, Diacamma ceylonense, Dolioponera fustigera, Ectomomyrmex javanus, Emeryopone buttelreepeni, Euponera brunoi, E. sikorae, E. sjostedti, Feroponera ferox, Fisheropone ambigua, Hypoponera punctatissima, Iroponera odax, Loboponera obeliscata, L. vigilans, Mayaponera becculata, M. cernua, M. conicula, M. constricta, Mesoponera ambigua, M. australis, M. caffraria, M. elisae rotundata, M. melanaria macra, M. papuana, M. rubra, M. subiridescens, Myopias darioi, M. maligna, Neoponera aenescens, N. apicalis, N. bugabensis, N. cavinodis, N. crenata, N. dismarginata, N. eleonorae, N. fiebrigi cf., N. fisheri, N. foetida, N. globularia, N. insignis, N. inversa, N. laevigata, N. luteola, N. obscuricornis, N. schoedli, N. striadinodis, N. unidentata, N. verenae, N. villosa, Odontomachus bauri, Odontoponera transversa, Pachycondyla lattkei, Parvaponera darwinii madecassa, Plectroctena strigosa, Ponera alpha, P. pennsylvanica, Psalidomyrmex procerus, Pseudoneoponera porcata, Pseudoponera gilberti, P. stigma, Rasopone costaricensis, R. cryptergates, R. cubitalis, R. guatemalensis, R. panamensis, R. pluviselva, R. politognatha, Simopelta oculata, S. transversa, and Streblognathus peetersi.

A claw with a basal tooth bears an acute prominence on the basal third of its inner margin (Fig. 12B). The basal tooth overhangs the outline of the inner margin of the claw and may bear several small, acute projections (Fig. 48D). This type of claw occurs in Bothroponera cariosa, B. pachyderma, B. talpa, Mayaponera arhuaca, M. pergandei, Megaponera analis, Neoponera carinulata, N. commutata, N. moesta, Ophthalmopone berthoudi, Pachycondyla crassinoda, P. harpax, P. impressa, P. lenis, P. procidua, P. striata, Phrynoponera pulchella, P. transversa, and Pseudoneoponera tridentata. A claw with a preapical tooth has an acute projection rising from the apical two-thirds of its inner margin (Fig. 48E). It is present in Dinoponera longipes, D. lucida, Hagensia havilandi marleyi, Harpegnathos saltator, Paltothyreus tarsatus, Platythyrea cribrinodis, P. punctata, P. turneri, Thaumatomyrmex fraxini, and T. zeteki. Pectinate pretarsal claws are shaped like a comb and are unique to Leptogenys among Ponerinae (Fig. 48F).

Finally, we found shape variations among the claws of the fore-, mid-, and hindlegs only in Buniapone amblyops and Promyopias silvestrii. These taxa present a propretarsal claw with a long basal tooth, while their meso- and metapretarsi claws are simple (Fig. 48G–I). This condition contradicts Bolton and Fisher (2008b) and Fisher and Bolton (2016), who stated the claws are simple in P. silvestrii.

Figure 48. 

A mesobasitarsus of Fisheropone ambigua in anterior view; worker (CASENT0906209); arrows indicate the stout, spine-like setae on the dorsal face of the tarsomere B pretarsus of Mayaponera constricta in ventral view; worker (CASENT0260254) C pretarsus of Simopelta transversa in oblique apicolateral view; worker (ANTWEB1008589) D pretarsus of Bothroponera pachyderma in oblique dorsal view; worker (ANTWEB1008567) E pretarsus of Hagensia havilandi marleyi in apicolateral view; worker (ANTWEB1008566) F pretarsus of Leptogenys wheeleri in ventral view; worker (ANTWEB1008541) G propretarsus of Promyopias silvestrii in dorsolateral view; worker (CASENT00178751) H metapretarsus of Promyopias silvestrii in apical view (CASENT00178751) I propretarsus of Buniapone amblyops in apicolateral view; worker (CASENT0384973); insert: metapretarsus of Buniapone amblyops in dorsoapical view (CASENT0384973). Images by FA Esteves (A, B, G–I) and RA Keller (C–F); available at AntWeb.org. Scale bars: 0.04 mm (A, B, F); 0.02 mm (C–E, G–I).

34. The arolium was absent or reduced to a membranous cuticular flap between the pretarsal claws of most taxa examined (Figs 12B, 48D–I). Exceptions were Belonopelta deletrix, Diacamma ceylonense, Harpegnathos saltator, Iroponera odax, Mayaponera, Neoponera, Parvaponera darwinii madecassa, Platythyrea cribrinodis, P. punctata, P. turneri, Rasopone guatemalensis, Simopelta oculata, S. transversa (Fig. 48C), Thaumatomyrmex fraxini, and T. zeteki.

Contrary to Schmidt and Shattuck (2014), we consider that Mayaponera constricta has indistinct arolia like all its congeners (Fig. 48B). In this species, the arolium is reduced to a cuticular flap, although more developed than what we classified as indistinct in other taxa. However, this feature was not noticeable under our stereo microscope.

35. The petiolar node of Corrieopone lacks a spine-like or any other acute projection and is narrow in profile, with its anterior and posterior surfaces tapering to an insignificant dorsal surface.

Ponerine taxa with an unarmed scale-like petiole are: several Anochetus (see CASENT0915154); Asphinctopone (CASENT0915481); Austroponera (FOCOL0965); Brachyponera (CASENT0915660); Buniapone (CASENT0903944); some Cryptopone (ANTWEB1008000); some Ectomomyrmex (CASENT0907270); Euponera fossigera species group [viz.: E. brunoi, E. fossigera Mayr (SAM-HYM-C002649B), E. malayana (Wheeler), E. sharpi Forel, E. wroughtonii Forel, E. wroughtonii crudelis Forel, and probably also E. sakishimensis (Terayama)]; Fisheropone (CASENT0906215); Hagensia (CASENT0256487); several Hypoponera (CASENT0281911); some Leptogenys (CASENT0902609); Mayaponera (USNMENT00442104); Mesoponera (CASENT0249169); some Neoponera (ANTWEB1014009); very few Odontomachus (CASENT0281868); very few Pachycondyla (UFV-LABECOL-000002); some Parvaponera (CASENT0915276); some Ponera (CASENT0235336); and Pseudoponera [CASENT0902509; except P. pachynoda (Clark), ANTWEB1008183].

36. The strigation on the posteroventral portion of the petiolar tergite of Corrieopone resembles that of Asphinctopone (CASENT0178221).

39. The spatulate projection rises from the posterior portion of the petiolar sternite and extends posteriad, overlapping either partially or entirely the remaining sternite. This definition departs from Keller (2011, character 111) in not requiring (a) the projection to extend beyond the posterior margin of the petiolar sternite and (b) close proximity between projection and remaining sternite. The reason is the character varies continuously, which invalidates both requirements. The variation comprises projections that are long and conceal the helcial sternite almost completely to partially (as in Phrynoponera pulchella, specimen ANTWEB1008573, and Platythyrea punctata, respectively; Fig. 49A); those that reach or almost reach the posterior margin of the petiolar sternite (as in Platythyrea turneri, Fig. 49B); and those even shorter (as in Asphinctopone silvestrii; Fig. 49C). In addition, projections may tightly envelop the remaining sternite (as in Phrynoponera pulchella and Platythyrea punctata, ANTWEB1008574; Fig. 49D); or a slight gap may be present [as in Platythyrea turneri, specimen ANTWEB1008575, and Phrynoponera gabonensis (André); Fig. 49E]; or the gap may be slightly broader (as in Rasopone jtl030; Fig. 49F) to much broader (as in Streblognathus peetersi; Fig. 49G).

Thus, according to our definition, the spatulate projection of the petiolar sternite is present in Austroponera, Asphinctopone, Brachyponera, Megaponera analis, Ophthalmopone, Phrynoponera, Platythyrea, Rasopone, and Streblognathus; see also Fisher and Bolton (2016) for the description of the sternite in some of these taxa. The petiolar sternite in Belonopelta deletrix, immediately anterior to its posterior margin, is projected ventrad and slightly posteriad; the same seems to happen in Thaumatomyrmex fraxini. According to the species redescription given by Mackay and Mackay (2010), Neoponera magnifica may also present the character.

40. Like Corrieopone, most ponerine genera present an infra-axial helcium (i.e., positioned ventrad the midheight of the anterior face of abdominal segment III; see Keller 2011, character 114). A few taxa examined present an axial helcium (i.e., positioned at midheight of the anterior face of abdominal segment III): Boloponera, Buniapone, Centromyrmex, Cryptopone (except C. guianensis), Dolioponera, Feroponera, Iroponera, Platythyrea, and Promyopias.

41. As far as we know, the prora is present and well-developed in most Ponerinae. It is usually indistinct in Platythyrea, but contrary to Fisher and Bolton (2016), it is well-developed in some species [as in P. lamellosa (Roger); Fig. 49H], and weakly projected but still visible in others [as in P. pilosula (Smith); Fig. 49I]. According to Schmidt and Shattuck (2014), the prora is absent in Iroponera, but SEM images of I. odax reveal that it is present, albeit weakly projected (Fig. 49J). According to Fisher and Bolton (2016), the trait is absent in Dolioponera, which agrees with what we saw in most specimens. However, SEM images of specimen ANTWEB1008521 show a weak projection on the anterior face of abdominal sternite III; we are unsure whether that detail is natural or an image artifact.

We consider the prora present in Mayaponera and Rasopone, in disagreement with Longino and Branstetter (2020). The trait, although small, is distinct in the profile view of M. becculata, M. conicula, M. constricta, and R. panamensis. In the first two species and R. panamensis, the prora rises from the anterior portion of the abdominal poststernite III (see specimens CASENT0249130, CASENT0644252). In M. constricta, it projects from the area in between the ventral margins of the helcial tergite arch and the anterior portion of the abdominal poststernite III (Fig. 49K) and resembles the condition seen in Dinoponera, Pachycondyla, and Streblognathus (ANTWEB1014000, CASENT0249148, and Fig. 49G, respectively). In M. arhuaca, M. cernua, M. pergandei, and other Rasopone species, the prora is indistinct in the profile view of undissected specimens, for it is a minute prominence located in the area between the ventral margins of the helcial tergite (as in Brachyponera, Fig. 49L), and may be fused entirely with it (as described for Phrynoponera by Bolton and Fisher 2008a).

43. We considered the girdling constriction present if the surface between pre- and postsclerites of abdominal segment IV was interrupted by a shallow or deep impression on the integument. A line, if present, only constituted a constriction if the integument was depressed.

Among taxa examined, the constriction is absent in Asphinctopone, Brachyponera sennaarensis (weakly impressed in other species), Corrieopone, Mesoponera (except M. caffraria), Odontomachus, Odontoponera, Simopelta, Streblognathus, and Thaumatomyrmex fraxini.

44. The stridulitrum is consistently present on abdominal pretergite IV in Austroponera, Belonopelta, Dinoponera, Harpegnathos, Megaponera, Neoponera, Odontoponera, Ophthalmopone, Streblognathus, and Thaumatomyrmex. The trait’s occurrence is variable in Anochetus, Bothroponera (present in members of the sulcata group), Brachyponera, Hypoponera, Mayaponera (only present in M. constricta), Mesoponera, Myopias, Odontomachus, Phrynoponera (only present in P. pulchella), and Ponera (Suppl. material 3: Table S3; see also Markl 1973; Schmidt and Shattuck 2014; Fisher and Bolton 2016). Schmidt and Shattuck (2014) state that it is universally present in Leptogenys and Platythyrea. However, Markl (1973), after a comprehensive taxa examination, affirmed that the occurrence of the trait is variable among species in both genera.

Figure 49. 

A petiole of Platythyrea punctata in ventral view; worker (ANTWEB1008574) B petiole of Platythyrea turneri in ventral view; worker (ANTWEB1008575) C petiole of Asphinctopone silvestrii in ventral view; worker (CASENT0824505) D petiole of Phrynoponera pulchella in profile; worker (ANTWEB1008573) E petiole of Phrynoponera gabonensis in profile; worker (CASENT0250060) F petiole of Rasopone jtl030 in profile; worker (CASENT0633075) G petiole of Streblognathus peetersi in profile; worker (CASENT0258947) H petiole and abdominal segment IV of Platythyrea lamellosa in profile; worker (CASENT0252018); arrow indicates the prora I petiole and abdominal segment IV of Platythyrea pillosula in profile; worker (CASENT0260481); arrows indicate the prora J petiole and anterior portion of the abdominal segment IV of Iroponera odax in ventral view; worker (ANTWEB1008537); arrow indicates the prora K petiole and anterior portion of the abdominal segment IV of Mayaponera constricta in profile; worker (CASENT0643469); arrow indicates the prora L posterior portion of the petiole and the helcium of Brachyponera croceicornis in ventral view; worker (ANTWEB1008564); arrow indicates the minute prora projected from the area in between the ventral margins of the helcium tergite. Images by RA Keller (A, B, D, J, L), FA Esteves (C,K), B Reynolds (E, H), JT Longino (F), M Esposito (G), and W Ericson (I); available at AntWeb.org. Scale bars: 0.2 mm.

Contrary to Fisher and Bolton (2016), the stridulitrum is present in Brachyponera obscurans (Fig. 50A) and at least two Afrotropical and Malagasy species of Mesoponera (Fig. 50B, C). For the record, it is absent in Boloponera ikemkha. In addition, the midline of the fourth abdominal pretergite is strigulate and dissimilar to the surrounding sculpture in Euponera sikorae (Fig. 50D, E) and Mesoponera caffraria (Fig. 50F); the ridges are set farther apart and form a narrower area in the latter species. However, whether they have a stridulatory function in those species is unclear. Finally, the stridulitrum is present in males of Mayaponera pergandei (Fig. 50G; contrary to Mackay and Mackay 2010) but absent in the worker caste (Fig. 50H, I). Assuming that W. P. Mackay correctly determined the two males we examined, this intercaste variation is interesting because (1) it has not been observed in ants (see Markl 1973), and (2) it suggests that this trait has a reproductive function in M. pergandei.

Figure 50. 

A abdominal pretergite IV of Brachyponera obscurans in dorsal view; worker (CASENT0059638) B abdominal pretergite IV of Mesoponera subiridescens in dorsal view; worker (CASENT0906219) C stridulitrum of Mesoponera subiridescens in dorsal view (CASENT0906219) D medial area of the abdominal pretergite IV of Euponera sikorae; worker (CASENT0497109) E close-up of the medial area of the abdominal pretergite IV of Euponera sikorae; worker (CASENT0134370) F medial area of the abdominal pretergite IV of Mesoponera caffraria; worker (CASENT0408614) G medial area of the abdominal pretergite IV of Mayaponera pergandei; male (CASENT0317474) H abdominal pretergite IV of Mayaponera pergandei in dorsal view; worker (CASENT0845437) I close-up of the medial area of the abdominal pretergite IV of Mayaponera pergandei; worker (CASENT0845437). Images by FA Esteves; available at AntWeb.org. Scale bars: 0.06 mm (A, F, G, I); 0.09 mm (B); 0.04 mm (C); 0.2 mm (D, E); 0.08 mm (H).

47. The hypopygium (abdominal sternite VII) is armed with spine-like setae that flank the sting in some Ponerinae. According to previous studies, the setae are present in Dinoponera, Ophthalmopone, Pachycondyla, Paltothyreus, some Leptogenys, and few Ponera (Schmidt and Shattuck 2014; Fisher and Bolton 2016). However, in Pachycondyla, we found that the hypopygial setae may be spine-like or aristate (Figs 10C–F, 12C, D; see details in the preceding subsection “Transfers between Neoponera to Pachycondyla”).

Hypopygial spine-like setae occur in several Brachyponera (Fig. 51A), Buniapone amblyops (Fig. 51B), Mayaponera becculata (Fig. 51C), some Mesoponera (Fig. 51D), Myopias darioi (Fig. 51E), M. maligna, some Neoponera (Fig. 10A, B; see subsection “Transfers between Neoponera to Pachycondyla”), Parvaponera darwinii madecassa (Fig. 51F), Promyopias silvestrii (Fig. 51G), and Rasopone panamensis (Fig. 51H; see also Suppl. material 3: Table S3). In Thaumatomyrmex fraxini and T. zeteki, the hypopygium vestiture is composed of minute spine-like microtrichia (Fig. 51I).

Figure 51. 

Posterior portion of abdominal segment IV in profile (only the hypopygium is seen in image C); in each image, a sample of stout, spine-like seta (or microtrichia, in image I) is highlighted in orange A Brachyponera chinensis; worker (CASENT0104738) B Buniapone amblyops; worker (CASENT0384786) C Mayaponera becculata; worker (CASENT0428720) D Mesoponera melanaria macra; worker (CASENT0159302) E Myopias darioi; worker (CASENT0810080) F Parvaponera darwinii madecassa; worker (CASENT0389498) G Promyopias silvestrii; worker (CASENT00178751) H Rasopone panamensis; worker (CASENT0644252) I Thaumatomyrmex fraxini; worker (ANTWEB1008597). Images by FA Esteves (A–H) and RA Keller (I); available at AntWeb.org. Scale bars: 0.04 mm.