Pachycondyla purpurascens

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Pachycondyla purpurascens
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Pachycondyla
Species: P. purpurascens
Binomial name
Pachycondyla purpurascens
Forel, 1899

Pachycondyla purpurascens casent0902515 p 1 high.jpg

Pachycondyla purpurascens casent0902515 d 1 high.jpg

Specimen Labels

Most specimens were a collected as individual foragers or extracted from leaf litter.

Identification

From Mackay and Mackay (2010): Longino (1997) pointed out the validity of P. purpurascens. The female and the worker are nearly identical to those of Pachycondyla impressa, differing only in having a longer clypeus. Pachycondyla purpurascens is closely related to the Peruvian and Bolivian Pachycondyla inca, but differs in having the dorsal surface of the mandible smooth or very weakly striate, whereas the mandible of P. inca is strongly striate. The size, shape of the clypeus and the smooth mandibles of P. purpurascens could cause confusion with Pachycondyla striata. It can be easily separated by the lack of a carina on the pronotal shoulder, which is present in P. striata. Additionally P. purpurascens lacks the prominent striae on the dorsum of the pronotum, which are present in P. striata.

Kempf (1961) suggested that this species would be shown to be a synonym of P. impressa as it was simply a little larger than the typical P. impressa, but cautioned that the differences in size should be further examined. He did not mention the differences in the lengths of the clypeuses. The differences appear to be consistent and P. purpurascens will be regarded as a valid species.

Distribution

COSTA RICA, PANAMA, COLOMBIA, PERU, VENEZUELA, TRINIDAD, BOLIVIA (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality), Honduras, Mexico, Panama.

Check distribution from AntMaps.

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Pachycondyla purpurascens for further details

Habitat

Pachycondyla purpurascens occurs in wet mountain forest and mountain hardwood cloud forest. Longino (1997) lists elevations of 800 - 1500 meters. (Mackay and Mackay 2010)

Biology

From Mackay and Mackay (2010): Dealate females were collected in February (Costa Rica) and April (Colombia). The specimen from Trinidad was collected in a cave in a nest made of guano fragments.

Longino (1997) found a nest in a steep bank along a trail. A worker captured a Gnamptogenys ant worker from a nest he was excavating. The forager moved irregularly back and forth but then went to a simple, circular hole in the bank. He excavated the hole horizontally into the bank to a depth of arm's-length plus trowel length. At that point, he began scooping out a few workers at a time and obtained a total of 16 workers.

Castes

Worker

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • purpurascens. Pachycondyla purpurascens Forel, 1899c: 12, pl. 1, fig. 10 (w.) COSTA RICA. Mackay & Mackay, 2010: 491 (q.). Subspecies of fuscoatra: Emery, 1901a: 45. Junior synonym of impressa: Kempf, 1961c: 195. Revived from synonymy: Mackay & Mackay, 2010: 489.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

From Mackay and Mackay (2010): The worker is a large (total length 16 mm) black ant. The mandible has approximately nine teeth; the anterior medial margin of the clypeus is concave. The length of the clypeus at the medial point (from the anterior edges of the frontal lobes) is long, approximately 0.4 mm. The eye is moderately large (0.6 mm) located one maximum diameter from the anterior margin of the head (side view). The scapes are moderately long, extending approximately the first funicular segment past the posterior lateral corner of the head. The sides of the head are convex, the posterior margin is concave. The pronotum is swollen at the shoulder, but does not form a carina. The promesonotal suture is well marked on the dorsum of the mesosoma; the metanotal suture is poorly marked and does not break the sculpture. The propodeal spiracle is slit-shaped. The petiole is rectangular-shaped when viewed in profile, with the anterior and posterior faces being nearly parallel and a well-developed horizontal face is present. The subpetiolar process consists of a small ventrally directed angle followed by a swollen region, which gradually diminishes in width posteriorly. The anterior face of the postpetiole is vertical and nearly forms a right angle with the dorsal face. The stridulatory file is absent on the second pretergite and the arolia are poorly developed.

Erect and suberect hairs are abundant on the mandibles, clypeus, dorsal and ventral surfaces of the head, posterior margin of the head, shaft of the scapes, erect hairs are generally absent on the sides of the head, except in the malar region, erect hairs are abundant on the dorsum of the mesosoma, on the petiole and all surfaces of the gaster, the hairs on the legs are erect to suberect.

The mandibles are finely striate and dull, the dorsum of the head is mostly punctate, but fine poorly defined striae are present near the posterior area of the frontal carinae, the mesosoma is punctate, but also has fine striae, which are mostly transverse on the dorsum of the pronotum, longitudinal on the mesonotum, longitudinal on the anterior ¼ part of the propodeum and transverse on the posterior ¾ part and mostly horizontal on the sides of the mesosoma, horizontal on the side of the petiolar node, but transverse across the dorsal face, all surfaces are dull.

Queen

From Mackay and Mackay (2010): The female (undescribed) is similar to the worker with a relatively elongate clypeus (length at the anterior medial point to the frontal lobes is approximately 0.4 mm), the eyes are moderate in size (maximum diameter 0.62 mm), the head length is 3.2 mm; head width is 3.0 mm. The pronotal shoulder is swollen, but does not form a carina. The propodeal spiracle is slit-shaped, the petiole and postpetiole are similar to those of the worker.

The pilosity and sculpture are similar to those of the worker.

Male

Males are not known for this species.

Type Material

Costa Rica, Caché. Lectotype worker here designated, Musee d'Histoire Naturelle Genève (Mackay and Mackay 2010)

Etymology

The name of this species is derived from the Latin word purpureus, meaning purple, possibly referring to the slight purple reflections of the integument of this species. (Mackay and Mackay 2010)

References

  • Emery, C. 1901b. Notes sur les sous-familles des Dorylines et Ponérines (Famille des Formicides). Ann. Soc. Entomol. Belg. 45: 32-54 (page 45, subspecies of fuscoatra)
  • Forel, A. 1899b. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 1-24 (page 12, pl. 1, fig. 10 worker described)
  • Kempf, W. W. 1961e. As formigas do gênero Pachycondyla Fr. Smith no Brasil (Hymenoptera: Formicidae). Rev. Bras. Entomol. 10: 189-204 (page 195, junior synonym of impressa)
  • Mackay, W. P., and E. E. Mackay 2010. The Systematics and Biology of the New World Ants of the Genus Pachycondyla (Hymenoptera: Formicidae). Edwin Mellon Press, Lewiston. Information from this publication is used with permission from the authors.