Parasyscia

A species-rich Old World lineage, Parasyscia is one of a number of genera that were formerly included in what is now the small genus Cerapachys. The species in this genus are small, cryptic ants that nest in decaying logs and under rocks. One species, Parasyscia zimmermani, is arboreal.

Identification
Borowiec (2016) - Worker Parasyscia workers are distinguished by a combination of propodeal spiracle positioned low on the sclerite and propodeal lobes present, constriction between abdominal segments III and IV, petiole dorsolaterally not marginate, no constriction between abdominal segments IV, V, and VI, pronotomesopleural suture fused, helcium axial, middle tibiae with a single pectinate spur, pretarsal claws unarmed, and abdominal segment III anterodorsally often marginate. Parasyscia is an exclusively Old World group and is most similar to Neocerapachys of the New World, which can be differentiated by narrower trench leading to the metapleural gland orifice, the presence of two patches of denser pilosity on abdominal tergite IV, and different palp formula (3,3 in Neocerapachys versus 3,2 or 2,2 in Parasyscia).

Male The males of Parasyscia have variably developed wing venation and are generally diverse, making them somewhat challenging to identify. Most species share characteristic venation: C and R·f3 are absent, Rs·f2–3 is present and runs all the way from Rs+M to 2r-rs, closing a submarginal cell. In addition, Parasyscia males have 13-segmented antennae, antennal toruli fully exposed, no constrictions between abdominal segments IV, V, and VI, narrow and axial helcium, and a single spur on each middle and hind tibia. Lividopone and Zasphinctus may have similar wing venation but the former has a broad supraaxial helcium and the latter has pronounced constrictions between abdominal segments IV, V, and VI. Along with Lioponera, Parasyscia males are among the most common of non-army ant doryline males in collections from the Old World. Except for specimens with much reduced wing venation, Lioponera can be distinguished by a ‘free stigmal vein’ formed in complete absence of Rs·f2–3.

Distribution
Borowiec (2016) - Distributed throughout the warm temperate and tropical Old World, extending into New Guinea and many Pacific islands but absent from Australia.

Biology
Two Parasyscia species, Parasyscia flavaclavata and Parasyscia opaca, were observed in the field in New Guinea (Wilson 1958). Parasyscia flavaclavata was seen raiding a colony of a Pheidole species. A nest of Parasyscia opaca was collected from a rotting log, containing <100 workers, a single queen, and brood and adults of the apparent prey, Strumigenys loriae. The brood of P. opaca consisted of larvae of the same size, suggesting synchronized brood production. Other species have been collected from rotten logs and under stones (Brown 1975), and at least one, Parasyscia zimmermani, is an arboreal nester (Sarnat and Economo 2012). Parasyscia imerinensis was observed in an urban habitat of the botanical garden and zoo in Antananarivo, Madagascar. Two workers were seen slowly walking on pavement stones shortly after dark. It is difficult to assess whether these individuals represented scouts or if this species forages solitarily (author’s observations).

Nomenclature

 *  PARASYSCIA  [Dorylinae]
 * Parasyscia Emery, in André, 1882c: 235. Type-species: Parasyscia piochardi, by monotypy.
 * Parasyscia subgenus of Cerapachys: Forel, 1892l: 243.
 * Parasyscia junior synonym of Cerapachys: Kempf, 1972a: 76.
 * Parasyscia as genus: Borowiec, 2016: 198.

Borowiec (2016) - Parasyscia was described as a genus by Emery in 1882 and shortly afterwards treated as a subgenus by Forel 1892. Most authors adopted Forel’s decision and finally Kempf synonymized it under Cerapachys in his catalog of Neotropical ants (Kempf 1972). Relatively few species have been described under this name, but in the sense proposed here it is equivalent to Brown’s dohertyi-cribrinodis group (Brown 1975), keyed with other Cerapachys in the same publication (Brown 1975).

Parasyscia has been identified as the sister group of Zasphinctus (Brady et al. 2014), but there have been no attempts to reconstruct the internal phylogeny. Material examined in collections suggests that many species remain to be described (author’s unpublished observations).

Worker
Borowiec (2016) - Head: Antennae with 11 or 12 segments. Apical antennal segment conspicuously enlarged, much broader than and longer than two preceding segments combined. Clypeus with 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- or 2-segmented. Labial palps 2-segmented. Mandibles triangular, with teeth. Mandibles triangular, edentate. Eyes present, composed of 1 to more than 20 ommatidia. Ocelli absent. Head capsule with differentiated vertical posterior surface above occipital foramen. Ventrolateral margins of head with or without lamella or 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 or not from collar by distinct ridge. Promesonotal connection with suture completely fused. Pronotomesopleural suture completely fused. Mesometapleural groove weakly impressed. Transverse groove dividing mesopleuron absent or 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 or without distinct dorsal edge or margin and rectangular in posterior view. Metapleural gland without bulla visible through cuticle. Propodeal lobes present, well developed. Metasoma: Petiole anterodorsally immarginate or marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal suture placed at suture and axial. Prora forming a U-shaped margin with median ridge. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III anterodorsally immarginate 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.

Queen
Borowiec (2016) - Alate gynes are known in a number of species, e.g. Parasyscia afer, Parasyscia imerinensis, Parasyscia reticulata. Ergatoid gynes are also known, for example in Parasyscia indica, Parasyscia schoedli, Parasyscia seema, and Parasyscia sudanensis. The ergatoid gyne of P. schoedli is extremely worker-like, does not possess ocelli, and differs form the worker mostly in relatively larger gaster and more erect pilosity. In P. seema intercastes or ergatoids with ocelli but no modifications to the mesosoma are known in addition to a gyne with well-developed mesosomal sutures. It is unclear, however, whether the latter is dealated or never possessed wings (Bharti and Akbar 2013).

Male
Borowiec (2016) - Head: Antennae with 13 segments. Clypeus with cuticular apron. Parafrontal ridges present. Torulo-posttorular complex vertical. Maxillary palps 2-segmented. Labial palps 2-segmented. Mandibles triangular, edentate. Ventrolateral margins of head without lamella or ridge extending towards mandibles and beyond carina surrounding occipital foramen. Carina surrounding occipital foramen ventrally absent. Mesosoma: Pronotal flange separated from collar by distinct ridge mostly on sides or not separated. Notauli absent or present. Transverse groove dividing mesopleuron present. Propodeal declivity reduced, with or without distinct dorsal edge or margin. Metapleural gland opening absent. Propodeal lobes present. Metasoma: Petiole anterodorsally immarginate or marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal suture placed at posttergite and axial. Prora forming a U-shaped margin with median ridge. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III more than half size of succeeding segment IV; latter 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. Girdling constriction between pre- and postsclerites of abdominal segments V and VI absent. Abdominal segment IV conspicuously largest segment. Abdominal sternite VII simple. Abdominal sternite IX distally armed with two spines, with lateral apodemes about as long as medial apodeme, directed anteriorly (towards head). Genitalia: Cupula long relative to rest of genital capsule and shorter ventrally than dorsally. Basimere broadly fused to telomere, with no sulcus trace at junction, and ventrally with left and right arms separated. Telomere gradually tapering toward apex. Volsella gradually tapering toward apex. Penisvalva laterally flattened, at apex hooked ventrally. 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 absent. Metabasitarsal glands absent. Hind pretarsal claws simple. Wings: Tegula present, broad, demiovate in shape. Vein C in fore wing absent. Pterostigma broad. Abscissa R·f3 absent. Abscissae Rs·f2–3 present, disconnected from Rs+M or connecting with Rs+M&M·f2. Cross-vein 2r-rs present, differentiated from Rs·f4 by presence of Rs·f2–3. Abscissae Rs·f4–5 present, fused in absence of 2rs-m. Abscissa M·f2 in fore wing present, separated from Rs+M by Rs·f2 or contiguous with Rs+M. Abscissa M·f4 in fore wing present, not reaching wing margin. Cross-vein 1m-cu in fore wing absent or present. Cross-vein cu-a in fore wing present, arising from M+Cu at variable distance, proximal, distal to, at or near M·f1. Vein Cu in fore wing present, with only Cu1 branch prominent. Vein A in fore wing with abscissa A·f1 present or with abscissae A·f1 and A·f2 present; A·f2 short. Vein C in hind wing absent. Vein R in hind wing absent. Vein Sc+R in hind wing absent. Abscissa Rs·f1 in hind wing absent. 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 abscissa A·f1 or with abscissae A·f1 and A·f2 present.

Larva
Borowiec (2016) - The larva of Parasyscia opaca has been described (Wheeler and Wheeler 1964a). Cocoon presence unknown.