Neocerapachys, Borowiec, Marek L., 2016

Borowiec, Marek L., 2016, Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae), ZooKeys 608, pp. 1-280 : 147-149

Taxon classification Animalia Hymenoptera Formicidae

Neocerapachys gen. n.

Type-species.

Cerapachys (Cerapachys) neotropicus , by present designation.

Neocerapachys is a rarely encountered Neotropical lineage with unknown habits.

Diagnosis.

Worker. Neocerapachys can be recognized by a combination of relatively low-positioned propodeal spiracle, propodeal lobes present, constriction present between abdominal segments III and IV, middle tibiae with a single spur, pretarsal claws unarmed, petiole dorsolaterally rounded (not marginate), constriction absent from between abdominal segments IV, V, and VI, pronotomesopleural Pronotomesopleural suture fused, helcium axial, abdominal segment III anterodorsally often marginate, and two spots where pilosity is denser than the surrounding hairs present laterally on abdominal tergite IV. Neocerapachys is superficially very similar to certain species of Parasyscia of the Old World but the latter never has lateral clumps of hair on abdominal tergite IV and its metapleural gland trench is broader than in Neocerapachys . Palp formulae also differ in these two lineages with 3,3 in Neocerapachys and 3,2 or 2,2 in Parasyscia . The neotropical Sphinctomyrmex shares several characters with Neocerapachys but is distinguished by constrictions between abdominal segments IV, V, and VI.

Male. Males of Neocerapachys possess well-developed propodeal lobes, mid and hind tibiae each with one spur, C and R·f3 veins in the fore wing, Rs·f2-3 abscissae present, cross-vein 2rs-m absent, third antennal segment conspicuously the shortest segment, and conspicuously marginate propodeal declivity. This combination will serve to distinguish it from all other lineages. Indomalayan Cerapachys is a relatively similar genus but it differs in longer, normally developed third antennal segment and eyes situated further away from mandibular insertions. In the Neotropics, Sphinctomyrmex males have similar wing venation but are easily told apart by constrictions visible between abdominal segments IV, V, and VI.

Description.

Worker.Head: Antennae with 12 segments. Apical antennal segment conspicuously enlarged, much broader than and longer than two preceding segments combined. Clypeus without cuticular apron. Lateroclypeal teeth absent. Parafrontal ridges reduced. Torulo-posttorular complex vertical. Antennal scrobes absent. Labrum with median notch or concavity. Proximal face of stipes projecting beyond inner margin of sclerite, concealing prementum when mouthparts fully closed. Maxillary palps 3-segmented. Labial palps 3-segmented. Mandibles triangular, with teeth. Eyes present, composed of 1-5 ommatidia. Ocelli absent. Head capsule with differentiated vertical posterior surface above occipital foramen. Ventrolateral margins of head with cuticular ridge extending towards mandibles and beyond carina surrounding occipital foramen. Posterior head corners dorsolaterally immarginate. Carina surrounding occipital foramen ventrally present. Mesosoma: Pronotal flange separated from collar by distinct ridge. Promesonotal connection with Pronotomesopleural suture completely fused. Pronotomesopleural suture visible, unfused partway to notal surface. Mesometapleural groove weakly impressed. Transverse groove dividing mesopleuron present. Pleural endophragmal pit concavity present. Mesosoma dorsolaterally immarginate. Metanotal depression or groove on mesosoma absent. Propodeal spiracle situated low on sclerite. Propodeal declivity with distinct dorsal edge or margin and rectangular in posterior view. Metapleural gland with bulla partially obscured but often discernable through cuticle. Propodeal lobes present, well developed. Metasoma: Petiole anterodorsally marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal Pronotomesopleural suture placed at posttergite and axial. Prora forming a simple U-shaped margin. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III anterodorsally marginate and dorsolaterally immarginate. Abdominal segment III more than half size of succeeding segment IV, which is weakly constricted at presegmental portion (uninodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like and cross-ribbed. Abdominal segment IV not conspicuously largest segment. Abdominal tergite IV not folding over sternite, and anterior portions of sternite and tergite equally well visible in lateral view. Girdling constriction between pre- and posttergites of abdominal segments V and VI absent. Girdling constriction between pre- and poststernites of abdominal segments V and VI absent. Pygidium large, with impressed medial field, and armed with modified setae. Hypopygium unarmed. Legs: Mid tibia with single pectinate spur. Hind tibia with single pectinate spur. Hind basitarsus not widening distally, circular in cross-section. Posterior flange of hind coxa not produced as raised lamella. Metatibial gland present as oval patch of whitish cuticle. Metabasitarsal gland absent. Hind pretarsal claws simple. Polymorphism: Monomorphic.

Male.Head: Antennae with 13 segments. Clypeus with cuticular apron. Parafrontal ridges present. Torulo-posttorular complex vertical. Maxillary palps 4-segmented. Labial palps 3-segmented. Mandibles triangular, edentate. Ventrolateral margins of head with cuticular ridge extending towards mandibles and beyond carina surrounding occipital foramen. Carina surrounding occipital foramen ventrally present. Mesosoma: Pronotal flange separated from collar by distinct ridge. Notauli present. Transverse groove dividing mesopleuron present. Propodeal declivity with distinct dorsal edge or margin. Metapleural gland opening absent. Propodeal lobes present. Metasoma: Petiole anterodorsally marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal Pronotomesopleural suture placed at Pronotomesopleural suture and supraaxial. Prora forming a simple U-shaped margin. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III more than half size of succeeding segment IV or about half size; latter weakly or strongly constricted at presegmental portion (transitional between uninodal waist and binodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like and cross-ribbed. Girdling constriction between pre- and postsclerites of abdominal segments V and VI absent. Abdominal segment IV not conspicuously largest segment. Abdominal sternite VII simple. Abdominal sternite IX distally armed with two spines curving dorsally at apices, with lateral apodemes about as long as medial apodeme, directed anteriorly (towards head). Genitalia: Cupula long relative to rest of genital capsule and of approximately equal length on both dorsal and ventral surfaces. Basimere broadly fused to telomere, basimere with no sulcus trace at junction, and ventrally with left and right arms abutting. Telomere gradually tapering toward apex. Volsella laterally flattened, at apex with dorsal lobe and hooked ventrally. Penisvalva laterally compressed, rounded at apex. Legs: Mid tibia with single pectinate spur. Hind tibia with single pectinate spur. Posterior flange of hind coxa not produced as raised lamella. Metatibial gland present as oval patch of whitish cuticle. Metabasitarsal glands absent. Hind pretarsal claws simple. Wings: Tegula present, broad, demiovate in shape. Vein C in fore wing present. Pterostigma broad. Abscissa R·f3 present and running toward distal wing margin and enclosing marginal cell with Rs·f5 or not. Abscissae Rs·f2-3 present, connecting with Rs+M&M·f2 or disconnected from Rs+M. Cross-vein 2r-rs absent. Abscissae Rs·f4-5 present, fused in absence of 2rs-m. Abscissa M·f2 in fore wing contiguous with Rs+M. Abscissa M·f4 in fore wing present, not reaching wing margin. Cross-vein 1m-cu in fore wing present. Cross-vein cu-a in fore wing present, arising from M+Cu and proximal to M·f1. Vein Cu in fore wing present, with both branches Cu1 and Cu2. Vein A in fore wing with abscissae A·f1 and A·f2 present. Vein C in hind wing absent. Vein R in hind wing present, extending past Sc+R but not reaching distal wing margin. Vein Sc+R in hind wing present. Abscissa Rs·f1 in hind wing present, shorter than 1rs-m. Abscissa Rs·f2 in hind wing present, not reaching wing margin. Cross-vein 1rs-m in hind wing present, about as long as M·f1. Vein M+Cu in hind wing present. Abscissa M·f1 in hind wing present. Abscissa M·f2 in hind wing absent or present. Cross-vein cu-a in hind wing present. Vein Cu in hind wing present. Vein A in hind wing with abscissae A·f1 and A·f2 present.

Gyne. Apparently alate or ergatoid with well-developed mesosomal sutures; with large eyes and three ocelli. This interpretation is based on one gyne specimen from Venezuela (John T. Longino personal collection, LACMENT 142669).

Larva. Not described. Presence of cocoons unknown.

Distribution.

This lineage ranges from Costa Rica south to southern Brazil and apparently is not very species-rich with only two species described.

Taxonomy and phylogeny.

Both currently named species have been described under Cerapachys and later discussed by Brown (1975) as similar to the ' dohertyi - cribrinodis group’ (here Parasyscia ). Brown even speculated that Neocerapachys neotropicus had been introduced from the Old World, but molecular data ( Brady et al. 2014, Borowiec, in prep.) prove that the resemblance to Parasyscia is superficial.

The exact phylogenetic position of Neocerapachys is not known with certainty, but in molecular analyses based on genomic data it is a part of a large New World clade that includes Acanthostichus , Cylindromyrmex , Leptanilloides , Sphinctomyrmex , and the Eciton genus-group (Borowiec, in prep.).

Biology.

I am not aware of any nest collections or observations of behavior of Neocerapachys .

Species of Neocerapachys

Neocerapachys neotropicus (Weber, 1939): Trinidad and Tobago, comb. n.

Neocerapachys splendens (Borgmeier, 1957): Brazil, comb. n.