Pachycondyla

Identification
From Mackay and Mackay (2010):

There does not appear to be a single, derived characteristic (synapomorphy) that can be used to define Pachycondyla and it could be paraphyletic or even polyphyletic. This has made the separation of Pachycondyla into several genera particularly attractive. Unfortunately, these genera apparently cannot be morphologically separated, making it an unattractive alternative. We have chosen to put all of the species into a single genus, following Brown (1973). Key characters, such as the shape of the propodeal spiracle, the degree of impression of the metanotal suture and the presence or absence of the stridulatory file appear to have little phylogenetic importance, as they appear or are lacking within members of different species complexes. Perhaps molecular techniques will allow us to understand the phylogeny of this genus. At the present time, there is no justification for the recognition of the subgenera.

Species richness
Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data



Regional Lists
New World Pachycondyla

Pachycondyla of Costa Rica

Biology
The following text is from Mackay and Mackay (2010):

Nesting Sites and Populations
Most of the New World species of Pachycondyla nest in dead wood or in hollow twigs (Byrne, 1994). Occasionally nests are found under stones and in the soil. Most colonies are small, usually with fewer than 200 workers (Fresneau, 1985; Goss et al., 1989; Dietemann and Peeters, 2000) to 500 workers (Beckers et al., 1989) and usually monogynous (Dietemann and Peeters, 2000). Reproductives and brood can be found in nests essentially any time of the year. Pachycondyla range from having a single queen (monogynous), including the Australian P. australis and South African P. wroughtonii, to having an ergatoid female (P. analis from Guinea) to having gamergates (P. kruegeri from South Africa) (Peeters and Crewe, 1986; Peeters, 1987).

The presence or absence of the arolium (adhesive pad) between the tarsal claws and the configuration of the claws is correlated with the nesting site (Orivel et al., 2001). One group of species, including all of the arboreal and three of the ground nesting species, have well developed arolia and the tarsal claws are spread and horn-shaped. The remainder of the species lacks the arolium and the tarsal claws are relatively closely spaced. The ability to walk upside down is strictly correlated to the presence of the adhesive pad.

Ants and Plants
Foragers of most of the species of Pachycondyla can be collected in vegetation and some, such as an unidentified species (listed as Neoponera sp.), visits the extrafloral nectaries of Bixa orellana (Bixaceae) (Bentley, 1977).

Several species nest in living plants, especially epiphytes, including P. goeldii (Orivel, et al., 1998). Beattie (1989) reports Pachycondyla occurring in domatia of myrmecotrophic plants, but does not specify the species or the specific plants. Fisher and Zimmerman (1988) found an unidentified species of Pachycondyla nesting in the orchid Aspasia principissa. Several species have been collected in orchids that were imported into the United States from Latin America (see index). Several other species of Pachycondyla have been reported from epiphytes (Tillandsia streptophylla and T. bulbosa [Bromeliaceae]), including P. crenata, P. unidentata and P. villosa at La Selva Biological Station in Costa Rica (Olson, 1991).

Many species nest in plants of the genus Cecropia. Pachycondyla villosa nests in a variety of places, including inside the stems of Cecropia hispidissima. Some of the species, including P. crenata and P. striatinodis, nest opportunistically, as their entrance holes are irregularly shaped and are often through wounds in the plant, rather than through the prostoma (Longino, website). Others, such as P. insignis, P. luteola and P. fisheri are apparently obligatory nesters in Cecropia, especially Cecropia insignis (and to a lesser extent  C. obtusifolia). These species are only found in Cecropia and at least P. insignis harvest Müllerian bodies and use the prostoma to gain entrance to the internodes (Longino, website). One of these species, P. luteola, is highly aggressive and swarms when the plant is disturbed, attacking the enemy (Longino, website). These associations appear to be the result of multiple independent colonizations of a plant lineage by diverse ant lineages (Longino, website). Other ant genera involved with Cecropia include Azteca and Crematogaster.

Some species nest in several genera of plants, such as P. crenata and P. unidentata, which nest in a diverse group of plants including bamboo, guava, Cordia nodosa, C. gerascanthus, C. alliadora, Tococa formicaria, Cecropia insignis, C. membranacea, C. polystachya,  C. sciadophylla,  Cattleya spp. [Orchidaceae], Costus laevis [Costaceae], Calathea ovandensis, Clibadium microcephalum, Byttneria aculeata [Sterculiaceae], Bromelia fastuosa, B. epiphytica, Triplaris paniculata and Tillandsia bulbosa [Bromeliaceae].

Pachycondyla striata can have an important impact on rain forest trees, apparently due to the greater concentration of nutrients near the nest (Passos and Oliveira, 2002). The soil from nests of P. harpax are significantly enriched in nutrients as compared with surrounding soils, but do not significantly improve seedling growth of the myrmecochore Calathea ovandensis [Marantaceae] (Horvitz and Schemske, 1986a, 1986b).

Foraging
These ants are generalist predators (Dejean et al., 1999) and scavengers, collecting fruit debris and vertebrate and invertebrate carcasses, especially Lepidoptera and Coleoptera larvae. Foragers generally orient themselves visually, forage independently of each other (Agbogba, 1984) and are thus individual foragers. Pachycondyla apicalis are individual foragers and apparently are not optimal foragers (Goss et al., 1989), but have regional specialization (Fresneau, 1985).

Several species prey predominantly on termites (Mill, 1983). Pachycondyla harpax specializes in termite workers (García-Pérez et al., 1997). Pachycondyla analis (= Megaponera foetens) and Pachycondyla sp. are important termite predators in Kenya (Abe and Darlington, 1985). P. harpax feeds on termites of the genus Nasutitermes (Overal, 1987). Pachycondyla marginata conducts well-organized predatory raids on the termite Neocapritermes opacus (Hölldobler et al., 1996a).

Foragers may recruit workers to a food source using Tandem running (Agbogba, 1984) and a chemical pheromone (Jessen and Maschwitz, 1985), but also use tandem running when a nest is moving to a new site (Traniello and Hölldobler, 1984; Jessen and Maschwitz, 1986; Wild, 2005). Pachycondyla caffraria in Senegal raid termite nests (Microcerotermes), using tandem running (Agbogba, 1992). The only time tandem running is used by P. apicalis is during the natural translocation of a colony (Fresneau, 1985). Other species such as P. verenae and P. tesseronoda use tandem running and chemical orientation (Maschwitz et al., 1974; Traniello and Hölldobler, 1984; Jessen and Maschwitz, 1986). Pachycondyla laevigata use a recruitment trail pheromone, which originates from the pygidial gland (Hölldobler and Traniello, 1980) and not the hindgut (Blum, 1966). Workers have individual specific trails (Jessen and Maschwitz, 1985). The trail pheromone of P. marginata originates from the pygidial gland and citronellal is the only effective trail pheromone (Hölldobler et al., 1996a). Isopulegol elicited an increase in locomotory activity and the chemical signal is enhanced by a shaking display performed by the recruiting ant (Hölldobler et al., 1996a). The secretions of the mandibular gland of three species were reported by Morgan et al. (1999).

Transportation of the food back to the nest may involve various mechanisms. Workers of P. villosa carry droplets of glucidic food between their mandibles, which are shared with other members of the nest (Dejean and Corbara, 1990a). Foragers of P. harpax and P. apicalis are important dispersers of the seeds of Calathea ovandensis (Marantaceae) (Horvitz and Schemske, 1986a, 1986b). Pachycondyla caffraria has two distinct types of foragers, one that specializes in hunting and the other in collecting liquids (Agbogba and Howse, 1992). Among the hunters, the “stingers” attack and paralyze the prey (termites); the “transporters” move the prey to the nest.

Nest Foundation
New nests are generally formed by a single female (called haplometrosis), which breaks off the wings after mating and establishes a colony in a small preformed cavity. New nests of P. caffraria are formed by single females, which raise the first brood on their own (Villet, 1990). New nests can form with more than a single female (called pleometrosis), with 2 (24 % of the nests) or 3 (16%) females occurring in founding nests of P. villosa (Trunzer et al., 1998). Eighty- two percent of the new nests are founded by between 2 and 7 females in P. marginata and the survival of incipient colonies was positively correlated with the number of females (Leal and Oliveira, 1995). The egg-laying rate of laboratory nests of single females does not differ from that in two female groups, but three-group females individually laid significantly fewer eggs (Trunzer, et al. 1998). After twenty-one weeks, multiple female nests had significantly more workers than single female nests (haplometrosis). Intercastes (members intermediate between workers and females) are found in P. verenae, which are able to mate and lay eggs (Düssmann et al., 1996). They differ from ergatoid females (permanently wingless caste) and gamergates (mated workers). A single gamergate is found in the nest of Pachycondyla sublaevis (Ito and Higashi, 1991; Dahbi and Jaisson, 1995). Ergatogynes (intermediates between workers and queens) are found in the Old World Pachycondyla analis (= Megaponera foetens) (Peters, 1991), P. verenae (listed as P. obscuricornis) and P. latinoda (see description). Closely related species may have ordinary gynomorphic females (P. wroughtonii) or gamergates (P. kruegeri) (Peeters and Crewe, 1986).

Reproductive Behavior
The behavior of Pachycondyla can be regulated by a diversity of mechanisms. In most species, the colony is relatively small (< 100) and worker/queen dimorphism is relatively slight. In some species, the workers are capable of mating and laying fertilized eggs (Peeters, 1993, 1997; Heinze et al., 1994). The males in the nest attempted to mate with the workers, but workers only accepted alien males (Ito, 1999). Colony odor is spread through the colony by nestmate grooming and not by trophallaxis (Soroker et al., 1998). In Pachycondyla stigma, the social organization and reproductive activity is linked with mutual antennal rubbings between nestmates (Oliveira et al., 1998). The ants specifically rub their antennae over the openings of the right tibial gland of the encountered nestmate. Inseminated queens engage in this activity at a higher rate than do virgin queens and workers. The reproductive dominance of the nest queen is enhanced by the extremely aggressive behavior of the workers towards other egg-laying queens. The workers always destroy the few eggs laid by these individuals. The nest queen, on the other hand, receives more food in the form of trophic eggs, has her eggs safely deposited on the egg pile and rarely participates in activities other than egg laying. When Oliveira et al. (1998) removed the queen from a colony, mutual antennal rubbings among virgin queens and aggressive behavior increased. Apparently, the tibial glands of the front legs of the queens produce either an inhibitory chemical signal, or more likely, the secretion signals the reproductive state to nestmates that respond by refraining from reproduction (Oliveira et al., 1998). Such multiple female nests may continue to be polygynous (have multiple females), without antagonistic behavior between the multiple females, even when workers are present (Trunzer et al., 1998). When intercastes of P. verenae were removed, dominance interactions occurred between the workers and reproductive eggs were then laid (Düssmann et al., 1996), suggesting they were functioning as nest females.

In some species such as the Malaysian P. tridentata more than 80% of the workers are inseminated, whether or not a queen is present (Sommer et al., 1994) and these workers compete directly for reproduction. The non-reproductive ants are much more aggressive than those with reproductive ability. A dominance hierarchy forms and the queen is not always at the top. Removal of the dominant workers results in a new hierarchy, with the callows (immature workers) being the most aggressive (Sommer and Hölldobler, 1992; Sommer et al., 1994). Queenless colonies of P. villosa establish linear or near-linear rank orders by antennation bouts and overt aggression (Trunzer et al., 1999). The top ranking workers laid the most eggs, but even low ranking workers laid numerous eggs. The eggs of low ranking workers were eaten, but at least some hatched into males (Trunzer et al., 1999). The behavior of P. apicalis is similar. There is one dominant worker and several subordinates in the nest (Oliveira and Hölldobler, 1990). This worker maintains her position by antagonistic interactions involving physical attack or the destruction of eggs laid by nestmates. Dominant workers usually have more developed ovaries, lay more eggs and spend more time attending the eggs than do the subordinate workers. Thus workers lay eggs in the presence of the nest female and it is possible that these haploid eggs may develop into workers (Oliveira and Hölldobler, 1990). Workers of the African P. caffraria and P. analis (= Megaponera foetens) lay eggs when the nest queen is not present, but only those of P. caffraria hatched (Villet and Duncan, 1992). Queenless groups of workers of P. harpax set up dominance hierarchies, using “boxing” and biting (Heinze et al., 1996). The dominant workers lay eggs and eat the eggs of other workers. The presence of larvae reduces the numbers of eggs, by feeding on the eggs and fewer eggs are laid when larvae are present (Heinze et al., 1996). The Old World workers of P. berthoudi also form dominance interactions (Sledge et al., 2001).

Pachycondyla sublaevis (and other members of the rufipes species complex from Australia) apparently has the smallest nest population (9 workers per colony) and completely lacks queens; inseminated workers of P. sublaevis are responsible for reproduction, one per colony (Peeters et al., 1991). Colonies of an unidentified Pachycondyla from Indonesia has some mated workers in the nest, but a single gamergate laid eggs (Ito, 1999). Pachycondyla kruegeri from South Africa is queenless, with a number of gamergates present in the nest (Wildman and Crewe, 1988).

No other ant genus has such an enormous diversity of social organization as is found in Pachycondyla (Hölldobler and Wilson, 2009).

Stridulation
Some of the species of Pachycondyla can stridulate by scraping a file on the second pretergite with the posterior edge of the first tergite (postpetiole) (Giovannotti, 1966; Pavan et al., 1997). Stridulation in P. commutata may serve to attract other foragers to a termite colony (Mill, 1982a), or may be an alarm signal, which causes the workers to scatter into the surrounding litter (Hermann, 1968; Mill, 1984).

Venom and Sting
Ants of the genus Pachycondyla are well known for their painful sting. The sting induced pain in humans considered to be a 2 on a scale of 1 - 4 (Schmidt et al., 1984). Pachycondyla uses the sting to subdue living prey and in defense the nest. Termites stung by P. commutata instantly become immobile (Mill, 1984). The bitter taste and burning sensation of the venom of P. apicalis is due to cyclic dipeptides and suggest that the venom serves both offensive and defensive functions (López and Morgan, 1997). The venoms of 12 species have paralytic and lethal effects on the cricket, Acheta domesticus (Orivel and Dejean, 2001). Although the species are closely related, there is a wide range of effects. The venoms cause a rapid, dose-related and reversible paralysis, followed by a second, slow-acting permanent paralysis and death within four days. Arboreal species have more efficacious venoms than ground nesting species, with higher potency and a faster-acting effect. This is presumably due to the greater possibility of escape in arboreal prey as compared to prey on the surface (Orivel and Dejean, 2001).

Workers of the Malaysian P. tridentata and the New World P. harpax and P. striata produce foam or a stream of viscous secretions at the tip of the gaster as a defense measure (Maschwitz et al., 1981; Overal, 1987, pers. obs.). Members of the rufipes complex display the same behavior (Peeters et al., 1991).

Associates
Pachycondyla goeldii shares its bromeliad nesting sites with hesperiid caterpillars (Orivel and Dejean, 2000). Pachycondyla goeldii nests with the ponerine ant Odontomachus mayi (Corbara et al., 1999) and others (P. crassinoda, P. gilberti, P. globularia and P. villosa) have an association with army ants of the genus Eciton, the nature of which is unknown.

Wheeler (1901) described the behavior of a commensal phorid fly larva, which raps itself around the neck of the Pachycondyla larva (phorid identified by Brues [1903, 1946] as Cataclinusa pachycondylae). The fly larva also participates with the feeding of the Pachycondyla larva on insect remains and may even feed

on the food supply of an adjacent larva. The workers lick and clean the commensals at the same time they care for their own larvae.

These ants are parasitized by eucharitid wasps (Heraty, 1998) and phorid flies in the genus Apocephalus (Brown and Feener, 1991, 1998). They are the hosts of histerid beetles of the subfamily Hetaeriinae (Helava et al., 1985). Pachycondyla sennaarensis is an intermediate host for the poultry cestode Raillietina tetragona in the Sudan (Mohammed et al., 1988). They are apparently eaten by the ant Blepharidatta conops (Brandão et al, 2001). A number of Batesian mimics of Pachycondyla are found. Pachycondyla apicalis is mimicked by the spider Castianeira memnonia ([Clubionidae] Reiskind, 1977; Wild, 2005). Pachycondyla carinulata and P. striatinodis are mimicked by the salticid spider Myrmarachne parallela; P. villosa by the salticid Zuniga magna (Reiskind, 1977).

Anatomy and Genetics
Little is known of the anatomy of members of this genus. Hölldobler and Engel-Siegel (1984) discussed the presence and absence of the metapleural gland in ants and demonstrated its presence in P. crassa and P. verenae (= P. obscuricornis). The digestive and excretory systems of P. villosa and P. verenae were described by Caetano (1988). Some of the members of Pachycondyla have a metatibial gland, a major synapomorphic character of the doryline section (Hölldobler et al., 1996b). Ortiz and Camargo-Mathias (2003) discuss the anatomy of the venom gland in P. striata and P. villosa. Hölldobler and Engel-Siegel (1982) describe the abdominal glands (tergal and sternal) of the males of P. apicalis and P. verenae. The report of 28 abdominal dermal complex glands in P. tridentata (Jessen and Maschwitz, 1983) suggests much work remains to be done on the glandular communication in Pachycondyla.

Little is known of the genetics of this genus. Pachycondyla rubra from Sarawak has 20 chromosomes (Nio Tjan et al., 1986). The karyotypes of some of the groups, including Bothroponera and Cryptopone have been studied by Imai et al. (1977). Microsatellite loci have been studied in P. inversa (Trindl et al., 2004) and P. luteipes (Takahashi et al., 2005). GenBank has 55 DNA sequence records for Pachycondyla and 7 for Cryptopone and gene sequences were used by Moreau et al. (2006).

Nomenclature

 *  PACHYCONDYLA [Ponerinae: Ponerini]
 * Pachycondyla Smith, F. 1858b: 105. Type-species: Formica crassinoda, by subsequent designation of Emery, 1901a: 42.

Description
From Mackay and Mackay (2010):

Worker
The worker is usually a medium to large ant (total length 1 cm or more), although smaller species are known (5 mm or less total length). Most species are black, a few are dark with yellowish appendages and a minority is yellow or orange. The mandible is well developed and the mandibular teeth range in number from 4 to more than 20. Most species have about a dozen teeth. The clypeus is divided transversely by a carina (called the midsagittal keel by Kempf, 1960a) into the anteclypeus and postclypeus, a carina which may be poorly developed and not obvious. The postclypeus usually projects medially over the anteclypeus. The frontal lobes are well developed and most or all of the attachment of the antenna is hidden with the head in frontal view. The eyes are nearly always developed and can be quite large, occupying ⅓ of the side of the head. The antenna has 12 segments. The scape usually extends to the posterior lateral corner of the head and extends past the posterior lateral corner of the head in many species. The pronotum is usually swollen at the shoulder and often forms a sharp carina. The mesonotum is usually relatively short and may be divided from the propodeum by well-developed metanotal suture. The propodeum never has spines or teeth, but may be angulate between the faces. The propodeal spiracle ranges in shape from circular to slit-shaped. The petiole varies greatly in shape, ranging from narrow, without a dorsal face, to broad, with a well-developed dorsal face. The postpetiole is fused to the remainder of the metasoma and the anterior face is often vertical and may form an angle with the dorsal face. A stridulatory file is often present on the second pretergite (fourth abdominal tergite). Arolia may be present between the tarsal claws and are apparently inflatable.

Bolton (2003) lists palpal formulae of 4,4; 4,3; 3,3 and 2,2 as possibilities for Pachycondyla (# of maxillary palp segments, # of labial palp segments). The New World species that were examined had 4-segmented maxillary palps and 4-segmented labial palps. The females of P. tarsata (Old World species, possibly found in Brasil) have a formula of 4,4 or 5,4, the males 6,4. Most of those members that have been examined and that previously belonged to Cryptopone have 2,2.

The coxal cavities are closed (completely surrounded by a raised ridge).

The metasternal process, located between the two posterior coxae, is always well developed and the shape is somewhat characteristic for each of the species complexes. The form ranges from well-formed, triangular lobes (aenescens, apicalis, crassinoda, foetida and laevigata species complexes), closely placed lobes (crenata and ferruginea species complexes) to fang-like (constricta and stigma species complexes) and finally to small, triangular processes (ochracea and mirabilis complexes). The last groups differ little from those of the ant genus Hypoponera. The shape is remarkably consistent within a species and in many cases they are distinct enough to be used for species recognition.

The form of the subpostpetiolar process is also important for defining species complexes (thanks to Shawn Dash for suggesting that this character could be useful), and will be discussed within each of the complexes. Basically there are four types: the first group consists of those that have no process, or the process consists of a slightly elevated triangle, and includes the complexes arhuaca, ferruginea, ochracea and rubra. The second group has a process which consists of a lobe which may be sharp, and includes the complexes aenescens, apicalis, constricta, crassinoda, crenata emiliae, foetida, and laevigata. The third group has a tooth similar to the second group, but the tooth is followed by a ventral longitudinal carina on the ventral surface of the postpetiole. This group includes P. tarsata and P. lenkoi (a species we have assigned to the stigma species complex, as it does not appear related to P. tarsata). The fourth group has a rounded collar-like flange which points somewhat anteriorly under the articulation with the petiole and has a slightly concave anterior face. This group includes only the stigma species complex. The form of the process in P. curiosa cannot be seen in the single holotype. In general, this structure is similar in the worker, female and male of these complexes, which may be useful for sorting males to a species complex. Most species have fairly abundant erect hairs, especially on the clypeus, the mandibles, the mesosoma, the petiole and the gaster, these hairs may be nearly completely missing, or may also be very abundant on the surfaces mentioned above, as well as on the head and the legs. Appressed pubescence is often present and may be sparse to dense and range in color from white to golden.

The workers vary in sculpturing, but most surfaces are usually punctate and opaque. Striae may be present on many surfaces and the worker may even be nearly completely smooth and glossy.

Female
The female is similar to the corresponding worker (Fig. 6). Most specimens are large (total length over 1 cm), but small species are also common. The mandibles are well developed, with several well-formed teeth (usually at least 10). The eye is large, with many ommatidia. The antenna has 12 segments; the scape usually extends at least to the posterior lateral corner of the head. The pronotum is often swollen at the shoulder and a sharp carina may be present. The mesosoma is thickened and adapted for flight and all of the known species in the New World have wings. The mesopleuron is clearly divided into an upper anepisternum and a lower katepisternum by the mesopleural oblique suture. The metanotum is always well developed, with well-developed scutellar metanotal and metanotal propodeal sutures, even in species in which the workers lack the metanotal suture. Unfortunately the suture is not more depressed in species in which the worker has a deeply depressed metanotal suture. The petiole and postpetiole are similar in form to the corresponding worker, as is the subpetiolar process. These characteristics make it possible to identify many females not associated with workers. The file on the second pretergite may be present, as well as the arolia on the tarsi. All of the tibiae have two spurs (possible exception: unknown female of P. leveillei).

The venation of the wing (Figs. 7 & 8) is typical for members of the tribe Ponerini, as well as most of the other tribes of the poneromorph ants. The costal, median and submedian cells are always well developed, as are the first cubital, marginal, the first and third discoidal cells and the second discoidal cell. We had hoped that the shapes and sizes of the cells, especially the first and third discoidal cells, would help define the species complexes and perhaps show the relationships between them. Unfortunately this does not appear to be the case, as there is much variability within a species complex, minor differences between the males and females and even differences between the two wings of a single specimen. Additionally, the males and/or females of many of the species are unknown.

Erect hairs are usually abundant on most surfaces, but are relatively sparse in many of the species. Appressed pubescence is similar to that of the corresponding worker.

Most surfaces are punctate and dull, although some may be covered with striate and some species are even predominately smooth and glossy.

Male
The male is usually small (total length less then 10 mm), although larger males are found. Most males are dark or black; a few are yellow or orange. The mandibles are tiny and do not meet medially. The palpal formula is normally 6,4, but some species, for example P. striata, have a palpal formula of 5,4 (Kempf, 1961). The clypeus is small and poorly defined and is often swollen medially. The eyes are well developed and usually occupy most of the side of the head. Three ocelli are present and range in diameter in different species. The frontal lobes and frontal carina are poorly developed, exposing the insertions of the scapes. The antenna has 13 segments. The scape is short (shorter than the funicular segments) and the pedicel is even shorter, the remaining segments are elongated. The pronotum may be swollen at the shoulder, but a distinct margin is absent. The scutum usually has parapsidal sutures; Mayrian sutures are usually present. The scutellum is often bulging above of the remainder of the mesosoma. The shape of the petiole varies among species and is often similar to that of the worker. The postpetiole is fused to the gaster, as in the worker. The stridulatory file is present on the second pretergite of species in which the workers and females have stridulatory files. The arolia are also developed in those species in which the arolia are developed in the workers and females. The down-turned pygidial spine is always well developed, as are the cerci. Males are relatively rare and the genitalia of only three common species were dissected (P. cognata, P. aenescens and P. villosa). They are of the generalized formicid type, with well-developed parameres, a well-developed bilobed aedeagus, but having tiny ventral teeth and poorly developed, knob-shaped volsellae.

Erect hairs are usually less dense than those of the corresponding worker, although some species have abundant erect hair. Appressed pubescence may also be present.

Most species are opaque and dull, but in a few species in which the workers are smooth and shiny the males are also mostly smooth and shiny.