Dinoponera Roger 1861
Creators: name: Dias, Amanda Martins
name: Lattke, John Edwin
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Dinoponera

description: Genus Dinoponera Roger, 1861
Dinoponera Roger, 1861: 37
(type species: Ponera gigantea Perty, 1833).
Diagnosis
Female
Mandible subtriangular. Anterior clypeal margin with lateral tooth along same longitudinal axis as antennal insertion. Head width greater than 4 mm. Pygidium and hypopygium each with lateral row of stout setae. Body length (BL) longer than 22 mm.
Male
Head width, including compound eyes, greater than 2.1 mm. Abdominal pretergite IV with stridulatory file. Meso- and metatibiae each with two pectinate spurs at apex. Easily diagnosed among Ponerinae by the large size (BL1> 12 mm).
Redescription
Female
MEASUREMENTS. Body length greater than 22 mm. Head width greater than 4 mm.
HEAD. In full-face view sub-rectangular, posterior margin concave, lateral margins subparallel, broadly convex. Anterior clypeal margin in frontal view with lateral tooth along same longitudinal axis as antennal insertion; clypeal disc with longitudinal raised area that narrows posteriorly between frontal lobes. Clypeal disc generally microareolate, laterally smooth to striate; anterior margin with hairs as long as or longer than clypeal tooth; external side of tooth usually with row of short hairs. Anterior tentorial pit region with oblique striae. Frontal lobe covers most of antennal insertion, anteriorly distinctly elevated above surrounding cuticle, internal margin forms fine longitudinal strip below frontal lobe surface; anterior region usually areolate, posterior constriction longitudinally striate. Malar area with varying amounts of longitudinal to oblique striae; if present, striae may reach all of anterior ocular margin and extend to gena, rarely surpassing posterior ocular margin. Gena may be smooth and shining to microareolate and opaque; pilosity variable. Anterior gena with or without longitudinal striae and variable appressed pubescence. Eye elliptical to broadly convex, placed on anterior half of head, occupying less than one-fourth of lateral cephalic margin, not reaching lateral cephalic margin in fullface view; circumocular sulcus present. Appressed pubescence present between eye and frontal lobe, extending posteriorly to frons. Frons smooth and shining to microareolate and opaque; insertion of hairs scalloped, posteriorly fading (particularly noticeable in D. hispida); pilosity variable; pubescence usually very sparse on median portion and densest laterally. Longitudinal median sulcus extends from between frontal lobes to frons, ending in tiny depression. Occipital corner strongly microareolate and opaque to smooth and shining (with no visible microsculpture with up to 32× magnification). Antenna with 12 segments. Scape extends beyond posterior margin of head; length usually longer than head width; smooth or microareolate; pilosity variable. First six funicular segments usually widening towards apex; funiculus with sparse hairs longer than scape diameter usually on first segments, rarely on four to five most apical segments; funicular segments densely covered by appressed and very short pubescence. Ventral surface smooth and shining to weakly microareolate or strigulate and opaque; strigulae absent to covering all surface or just anterior half; pilosity variable; hypostomal tooth usually longitudinally striate. Labrum smooth or weakly transversely striate-punctate; median longitudinal sulcus present or absent. Mandible subtriangular; usually with seven teeth; basal tooth separated from other teeth by diastema; dorsum weakly longitudinally striate only at inner base or along masticatory margin; long hairs present along masticatory margin; integument widely impressed at hair insertions. Mandible ventrally curved in lateral view. Mandible in ventral view with shallow longitudinal basal sulcus that gradually fades apicad; sulcus and row of long, flexuous hairs parallel masticatory margin. Discal area of stipes depressed, usually smooth, sometimes weakly rugulose; usually two long and flexible hairs visible at base. Submentum with weak sulcus at base; discal protuberance present; usually no microsculpturing visible. Palpal formula 4,4.
MESOSOMA. In lateral view, dorsal margin slightly divided by promesonotal junction; pronotum slightly higher than rest of mesosoma. Dorsal margin of pronotum in lateral view convex. Pronotum with lateral dorsoposterior swelling of variable convexity; smooth and shining to opaque and microareolate and/or rugulose; lateral surface densely covered by appressed to decumbent pubescence. Anteroventral corner of pronotum rounded, angled or toothed. Propleuron densely punctulate and pubescent. Prosternal process longer than wide. Mesonotal and propodeal dorsal margins in lateral view continuous and widely convex, metanotal groove slightly impressed. Mesopleuron and mesosternum separated by welldeveloped carina. Anepisternum usually with mesopleural pit next to mesometapleural suture and to metathoracic spiracle. Mesometapleural suture straight and well developed. Metanotal spiracular sclerite ovoid. Dorsal and declivitous propodeal margins in lateral view rounded and continuous; propodeal spiracle opening vertical to oblique and slit-shaped; spiracle at same level as surrounding propodeal surface; metapleural-propodeal suture well-marked and straight, or weak and sinuous. Mesometapleuron and lateral surface of propodeum punctulate; appressed pubescence variable in length and density. Mesonotum and propodeal dorsum usually densely covered with punctulae bearing medially converging pubescence. Mesosoma usually with numerous long hairs, distance between each hair usually less than half length. Coxae, femora and tibiae microareolate or smooth, with long hairs throughout each surface, separated from each other by distance less than half its length. Protibial apex with robust seta and well-developed pectinate spur, spur lamellate on inner base. Protibia with pubescence concentrated on opposing side of robust seta. Meso- and metatibia each with row of robust setae around entire apex, each apex with simple spur and pectinate spur; pubescence more concentrated on opposite surface of pectinate spur. Posterior surface of probasitarsus with basal concavity containing row of dark brown setae and parallel row of fine, light brown hairs; surface covered by thick yellow hairs. Tarsi with dark brown setae concentrated ventrally on apex of each tarsomere. Tarsal claws bidentate, arolium absent.
METASOMA. Petiolar node in lateral view usually robust and sub-rectangular; taller than long; lateral surface smooth and shining to microareolate and opaque; anterior margin with short, whitish decumbent hairs. Node longer than broad in dorsal view, narrower than either propodeum or abdominal tergite III; lateral margins subparallel to anterodorsally converging, always with rounded corners; integument shining or opaque. Hairs present in variable density. Posterior surface usually with shallow longitudinal sulcus. Petiolar sternite height in lateral view always higher anteriorly than posteriorly; subpetiolar process anteroventrally projecting; anterior apex rounded or longitudinally carinate. Anterior margin of abdominal tergite III in lateral view broadly convex and vertical; dorsal margin broadly convex; prora discrete and slightly concave ventrally. Gastral spiracles rounded. Abdominal tergite III in dorsal view smooth and shining to microareolate and opaque, with hairs of variable length and density; pubescence either present on entire surface or concentrated only laterally. Abdominal pretergite IV with fine transverse striae, stridulatory file of variable size (usually well-developed in D. lucida Emery, 1901 and D. longipes Emery, 1901). Pygidium and hypopygidium each with lateral row of stout setae. Apex of hypopygium ending in two robust triangular spines which are usually covered dorsally by pygidium.
COLOR. Integument black. Male
MEASUREMENTS. Body length (BL1) greater than 12 mm. Head width greater than 2.1 mm.
HEAD. In full-face view ovoid, wider than long. Anterior margin of clypeus with a transverse lamella, concave; surface of clypeal disc with slight swelling. Anterior tentorial pit large. Epistomal sulcus usually broadly convex. Supraclypeal area flat and triangular-shaped, located between antennal sockets. Distance between antennal sockets less than their maximum diameter. Torular arch simple, exposing antennal condyles. Frontal carina reduced to a short median longitudinal swelling between posterior margins of antennal sockets. Eye large and convex, occupying entire lateral cephalic margin; inner margin emarginate at height of antennal socket. Median and lateral ocellus present; lateral ocellus surpassing posterior head margin in full-face view, except in some specimens of D. grandis. Posterior margin of head convex. Head punctulate and slightly microareolate, varying from shining to silky sheen; with decumbent to suberect yellowish pubescence; variable density of hairs. Antenna with 13 segments; filiform. Scape wider than all other segments; at least two times as long as pedicel; length approximately half that of third antennal segment. Antenna with appressed pubescence; hairs, if present, only on funiculus. Ventral surface of head varies from microareolate and subopaque to smooth and shining. Mandible reduced, edentate, spoon-shaped in lateral view; weakly punctulate and shiny. Labrum reduced, narrower than labium; anterior margin concave, rarely rounded in D. quadriceps Kempf, 1971. Palpal formula 4,3, sometimes 5,3.
MESOSOMA. Pronotum in dorsal view narrow, with concave posterior margin; posterolateral corner acute and bulging. Mesoscutum in dorsal view rounded; with anteromedian longitudinal carina and lateral parapsidal line; notaulus present or absent; in lateral view with convex dorsal margin. Mesopleural sulcus oblique and well-developed; mesopleural pit easily distinguible, opening anteroventrally. Spiracular sclerite approximately rounded, opening posterodorsally. Scutoscutellar sulcus easily distinguible and usually scrobiculate. Mesoscutellum in dorsal view with concave anterior margin and straight to convex posterior margin, usually with lateral strigulae; dorsal margin in lateral view strongly convex. Metanotum usually with silky sheen, narrow and sub-rectangular in dorsal view, convex in lateral view; metanotal disc slightly rugulose, laterally strigulate. Metapleuron with oblique median depression at posterior metapleural pit; metapleural pit opening usually facing anteroventrally, except in some specimens of D. grandis and D. lucida. Metapleuron with anteroventral carina that extends briefly posterodorsally. Metapleural-propodeal suture forms carina that fades dorsally to propodeal spiracle, becoming broad, sometimes scrobiculate, sulcus. Anterior margin of propodeum in dorsal view with median notch; dorsal and declivitous margins of propodeum slightly discontinuous, sometimes separated by weak carina; propodeal spiracle slit-shaped. Mesosoma varies from microareolate and subopaque to smooth and shining, becoming coarsely punctate on declivitous surface of propodeum, except in D. grandis; usually with decumbent pubescence; long hairs present or absent. Legs very slightly microareolate and shining; densely pubescent; long hairs present or absent. Protibial apex sometimes with one stout seta; protibial spur well-developed and pectinate with lamellate inner base. Meso- and metatibiae each with two pectinate spurs at apex: one well-developed and the other less developed. Posterior surface of probasitarsus with basal concavity containing row of short setae. Tarsi with decumbent setae, usually more concentrated on apex of each tarsomere; claws bidentate; arolium well-developed. Wings covered by short pubescence. Forewing with pterostigma and following longitudinal veins: C, Sc+R, R, Rs+M, M, M+Cu, Cu and A; crossveins 2r-rs, 2rs-m, 1m-cu and cu-a present. Hindwing with following longitudinal veins: R+Rs, Rs, M+Cu, M, Cu and A; crossveins 1rs-m and cu-a present.
METASOMA. Petiolar node in lateral view with rounded dorsal margin, anterior and posterior margins forming a continuous curve, usually with posterior hump; spiracle oval to rounded. Petiolar sternum continuous, lacking well-developed subpetiolar process, usually longitudinally carinate. In dorsal view longer than wide with rounded corners. Sculpturing varies from microareolate and subopaque to smooth and shining; pubescence and pilosity of variable density. Anterior margin of abdominal tergite III in lateral view broadly convex and curving posterad. Gastral spiracles oval to rounded. Abdominal pretergite IV with stridulatory file. Well-marked constriction between abdominal segments III and IV; abdominal tergite VIII (pygidium) triangular to spiniform. Cercus apically dilated, with long hairs; hypopygium elongate, posterior margin concave to straight. Sculpturing varies from microareolate and subopaque to smooth and shining; pubescence and pilosity of variable density.
GENITALIA. Basal ring in dorsal view trapezoid, with lateral margins converging anteriorly; dorsoanterior margin thicker, forming lateral loop and median invagination; each loop surrounds a fenestra. Basal ring in lateral view with dorsal margin varying from straight to very concave, some species having anterior lobe; anteroventral process varying from rounded to subquadrate to subtriangular. Parameres notably divided in two regions: gonocoxite anteriorly and gonostylus posteriorly; gonostylus varying from broad and rounded to narrow and sharp. Cuspis volsellaris in lateral view finger-like and ventrally torulose, size variable; digitus volsellaris widening posteriorly, ventral margin varying from broadly to strongly concave; posterior region torulose. Penisvalva highly variable among species, with ventral margin serrated.
COLOR. Integument in shades of brown, with legs usually lighter.
Remarks
This genus is rarely mistaken with any other due to its enormous size. Dinoponera shares some synapomorphies with Pachycondyla Smith, 1858, the most notable being the presence of a row of stout setae on the hypopygium on each side of the sting (Schmidt & Shattuck 2014). However, females of Pachycondyla have no tooth on the anterior margin of the clypeus and rarely exceed 2 cm in body length. Neither females nor males of Pachycondyla have a stridulatory file on abdominal pretergite IV, a character present in both sexes of Dinoponera. A possible karyotypic apomorphy of Dinoponera is the presence of a pair of pseudo-acrocentric chromosomes, observed in D. grandis, D. gigantea, D. lucida and D. quadriceps (Santos et al. 2012).
Biology
Nests are always constructed in the soil, usually close to the base of trees or in areas shaded by vegetation (Araujo et al. 1990; Morgan 1993; Paiva & Brandão 1995; Fourcassié et al. 1999; Fourcassié & Oliveira 2002; Peixoto et al. 2010). Each nest may have one to thirty entrances, and some may be polydomic (Morgan 1993; Paiva & Brandão 1995; Fourcassié & Oliveira 2002). The entrances may contain branches and loose soil, forming mounds in D. longipes (Morgan 1993; Fourcassié et al. 1999; Peixoto et al. 2010). Nest depth varies from 10 to 143 cm,with species from more arid environments, such as D. quadriceps and D. grandis, usually having deeper nests. Nests are distributed in patches, and the spatial arrangement within each patch may be random or influenced by intraspecific territorial competition (Araujo et al. 1990; Paiva & Brandão 1995; Fourcassié & Oliveira 2002; Vasconcellos et al. 2004). Local density of nests can vary from 15 to 180 per hectare (Vasconcellos et al. 2004; Tillberg et al. 2014). In D. longipes, Morgan (1993) estimated an average distance of 35 m between nests.
The average number of workers per colony varies from 13 to 78, and can reach more than 140 in D. quadriceps (Paiva & Brandão 1995; Monnin & Peeters 1998; Monnin et al. 2003). Division of labour occurs mainly because of age polyethism, with the oldest workers responsible for activities outside the nest (Peixoto et al. 2008). Foraging is always solitary, regardless of resource size (Araújo & Rodrigues 2006; Azevedo et al. 2014). Their diet is omnivorous, with a preference for angiosperm seeds and living or dead invertebrates (Fourcassié & Oliveira 2002; Araújo & Rodrigues 2006; Peixoto et al. 2010; Tillberg et al. 2014). Each worker maintains fidelity to a foraging route, with only slight deviations while searching for food (Fourcassié et al. 1999; Fourcassié & Oliveira 2002; Vasconcellos et al. 2004; Tillberg et al. 2014). Studies suggest that spatial orientation occurs mainly through large-scale visual cues (Fourcassié et al. 1999; Araújo & Rodrigues 2006; Tillberg et al. 2014).
In Dinoponera there has been loss of the queen; consequentially, reproduction is carried out by workers called gamergates (Haskins & Zahl 1971; Peeters & Crewe 1984; Araujo et al. 1990; Peeters 1991; Peixoto et al. 2008). All workers have reproductive potential, but a hierarchical system of dominance guarantees that the colonies are usually monogynous (Monnin & Peeters 1999; Monnin et al. 2003; Peixoto et al. 2008). Each colony has a cadre of workers of elevated hierarchical status that usually compete with each other for the reproductive role. These workers are often referred to as alpha, beta, gamma, and delta, being defined by the frequency and intensity of specific behaviours (Monnin & Peeters 1999; Peixoto et al. 2008). The gamergate is the alpha, the highest status in the colony (Monnin & Peeters 1999). Agonistic interactions performed by workers of higher status usually are blocking, gaster rubbing and gaster curling (Monnin & Peeters 1999; Peixoto et al. 2008). When beta, gamma or delta workers lay unfertilized eggs, the gamergate often recognizes them and destroys them by oophagy (Monnin & Peeters 1997). Dominance hierarchy is also determined by age (Araujo et al. 1990), as usually only young workers have high level positions (Monnin & Peeters 1999). As workers age their ovaries atrophy and they lose their reproductive capacity (Araujo et al. 1990). Thus, a newly emerged worker has a good chance to become a beta and possibly an alpha (Araujo et al. 1990; Monnin & Peeters 1999). Gamergates, however, may be relatively old, which suggests that fertilization is an important factor that prevents ovary atrophy (Araujo et al. 1990).
Reproduction occurs when a virgin alpha leaves the nest at night and waits for a male to fertilize it (Monnin & Peeters 1998). Male attraction probably occurs through pheromones produced only by alpha females (Monnin & Peeters 1998). After mating, the male genitalia remain attached to the gamergate, ensuring monandry (Monnin & Peeters 1998). A newly fertilized alpha can replace a dead gamergate or found a new colony by fission (Monnin & Peeters 1998). Fission can be gradual, as demonstrated for D. quadriceps and D. lucida (Peixoto et al. 2010; Medeiros & Araújo 2014). Initially the new gamergate and other workers can migrate to a nearby nest and remain in contact with the parental nest. After this polydomous stage, that may continue for months, the two colonies gradually become independent from each other (Peixoto et al. 2010; Medeiros & Araújo 2014).
Several invertebrates can inhabit Dinoponera nests. The most common taxa are Termitidae, Gastropoda, Corinnidae, Zygentoma, Tenebrionidae, Histeridae, Phoridae, and Isopoda (Paiva & Brandão 1995; Vasconcellos et al. 2004). Ants of the genus Pheidole Westwood, 1839 are often found in nests of several species of Dinoponera (Paiva & Brandão 1995; Vasconcellos et al. 2004; Peixoto et al. 2010).
Distribution
Dinoponera has been recorded in most Brazilian states except Amapá, Roraima and Rio de Janeiro. The genus also occurs in other countries of South America, such as Colombia, Ecuador, Peru, Bolivia, Paraguay and Argentina (Kempf 1971; Lenhart et al. 2013). Lenhart et al. (2013) recorded the genus in Guiana, but this single record may be a labeling error, since no other records have been reported throughout the region between the Rio Negro in the Amazon and the Bartica district of Guiana.
Taxonomic synopsis
D. gigantea (Perty, 1833)
D. grandis (Guérin-Menéville, 1838) revived species
= D. australis Emery, 1901 syn. nov.
= D. australis brevis Borgmeier, 1937
= D. australis bucki Borgmeier, 1937 syn. nov.
= D. australis nigricolor Borgmeier, 1937 syn. nov.
= D. snellingi Lenhart, Dash & Mackay, 2013 syn. nov.
D. hispida Lenhart, Dash & Mackay, 2013
D. longipes Emery, 1901
D. lucida Emery, 1901
D. mutica Emery, 1901
D. nicinha sp. nov.
D. quadriceps Kempf, 1971
= D. opaca Kempf, 1971
Key to females of Dinoponera Roger, 1861
1. Integument mostly smooth and shining; microsculpturing not visible on first gastric tergite (best seen at 32 × magnification) (Fig. 3A)................................................................................................2
– Integument mostly microareolate and opaque; microsculpturing always visible on first gastric tergite (best seen at 32 × magnification) (Fig. 3B)..............................................................................6
2. Petiolar node in lateral view with the anterodorsal angle at a level clearly lower than the posterodorsal angle (Fig. 4A). Anteroventral corner of pronotum in lateral view with a tooth or forming an acute angle ........................................................................ D. lucida Emery, 1901 (east of Brazil)
– Petiolar node in lateral view with the anterodorsal angle higher, at the same level as or slightly lower than the posterodorsal angle (Fig. 4B). Anteroventral corner of pronotum in lateral view without a tooth, forming obtuse angle at most.................................................................................3
3. Body covered by thick and stiff hairs (Fig. 5A). Ventral surface of head posteriorly with wellmarked transverse strigulae posteriorly ...... D. hispida Lenhart, Dash & Mackay, 2013 (Brazil: Pará)
– Body covered by slender and flexuous hairs (Fig. 5B). Ventral surface of head posteriorly without strigulae; if strigulae present, only anterolaterally.............................................................4
4. Petiolar node in lateral view with its anterodorsal angle at a level clearly higher than the posterodorsal angle (Fig. 6A) ..... D. longipes Emery, 1901 (northwest of Brazil, Colombia and Peru)
– Petiolar node in lateral view with its anterodorsal angle slightly lower or at approximately the same level as the posterodorsal angle (Fig. 6B).................................................................5
5. Dorsal margin of petiolar node in lateral view convex (Fig. 7A). Golden pilosity present on frons and first gastric tergite. First gastric tergite with sparse pubescence on entire surface ...... .......................................................................................... D. nicinha sp. nov. (northwest of Brazil)
– Dorsal margin of petiolar node in lateral view straight (Fig. 7B). Chestnut pilosity present on frons and first gastric tergite. First gastric tergite with dense pubescence laterally ........................ ........................ D. mutica Emery, 1901 (northwest and midwest of Brazil, Bolivia and Paraguay)
6. Malar area with striae that reach entire anterior eye margin (Fig. 8A); hind basitarsus less than 6 mm long ........ D. grandis (Guérin-Menéville, 1838) (Argentina, Bolivia, Brazil and Paraguay)
– Malar area without striae or with weak striae that do not reach entire anterior eye margin (Fig. 8B); hind basitarsus usually more than 6 mm long........................................................7
7. Anteroventral corner of pronotum in lateral view without tooth, at most forming an obtuse angle (Fig. 9A). Ventral surface of head without striae ................................................................. .......................................................................... D. quadriceps Kempf, 1971 (northeast of Brazil)
– Anteroventral corner of pronotum in lateral view with tooth or forming acute angle (Fig. 9B). Ventral surface of head with striae at least on the anterior half ................................................. ..................................................... D. gigantea (Perty, 1833) (north of Brazil, Colombia and Peru)
Key to males of Dinoponera Roger, 1861
For detailed images of genitalia see Tozetto & Lattke (2020).
1. Antenna without long hairs (Fig. 10A). Anteroventral corner of volsella projecting ventrally ..................... D. grandis (Guérin-Menéville, 1838) (Argentina, Bolivia, Brazil and Paraguay)
– Antenna with long suberect to erect hairs, clearly longer than maximum scape diameter (Fig. 10B). Anteroventral corner of volsella bidentate............................................................2
– Antenna with thick and stiff decumbent hairs, usually shorter than maximum scape diameter (Fig. 10C). Anteroventral corner of volsella projecting anteriorly.................................................3
2. Notaulus slightly impressed on mesoscutum (Fig. 11A). Penisvalva ending in rounded apex. Gaster with sparse suberect long hairs ..... D. gigantea (Perty, 1833) (north of Brazil, Colombia and Peru)
– Notaulus absent (Fig. 11B). Penisvalva ending in a subacute apex. Gaster without long hairs .. ............................................................................. D. quadriceps Kempf, 1971 (northeast of Brazil)
3. Abdominal tergite VIII triangular, with a very sharp apex (Fig. 12A). Penisvalva ending in a posteroventral lobe ............................................................... D. lucida Emery, 1901 (east of Brazil)
– Abdominal tergite VIII spiniform (Fig. 12B). Penisvalva without a posteroventral lobe.......4
4. Penisvalva in lateral view with a rounded apex; anteroventral corner with a long and very sharp spine .................................................. Dinoponera morphospecies 1 (northwest of Brazil)
– Penisvalva in lateral view with a wedge-shaped apex; anteroventral corner with a tooth ..... ...................................... D. longipes Emery, 1901 (northwest of Brazil, Colombia and Peru)
description: Published as part of Dias, Amanda Martins & Lattke, John Edwin, 2021, Large ants are not easy - the taxonomy of Dinoponera Roger (Hymenoptera: Formicidae: Ponerinae), pp. 1-66 in European Journal of Taxonomy 784 (1) on pages 6-16, DOI: 10.5852/ejt.2021.784.1603, http://zenodo.org/record/5798246