Pachycondyla obscuricornis Emery

Wild, A. L., 2005, Taxonomic revision of the Pachycondyla apicalis species complex (Hymenoptera: Formicidae)., Zootaxa 834, pp. 1-25 : 9-10

Pachycondyla obscuricornis Emery

(Figs. 3, 4, 8)

Pachycondyla flavicornis var. obscuricornis Emery 1890: 58.

Neoponera flavicornis var. obscuricornis (Emery 1890); Emery 1901: 47. First combination in Neoponera .

Neoponera obscuricornis (Emery 1890); Kempf 1972: 162 (part).

Pachycondyla obscuricornis Emery 1890; Brown, in Bolton 1995: 308. Revived combination in Pachycondyla ; this combination is implicit in Brown (1973) and explicit in Duelli and DuelliKlein(1976) but as a misidentification of verenae (Forel 1922).

Pachycondyla sp. cf. obscuricornis Wild 2003: 12.

Type data: Pachycondyla flavicornis var. obscuricornis Emery . Brazil. Pará (s. loc.) [2w SYNTYPES, MHNG, examined; 1w SYNTYPE, MCSN, examined].

Other material examined:

Bolivia. Santa Cruz: Las Gamas, P. N. Noel Kempf Mercado [ PSWC] . Brazil. Pará: Tucurui, Margem esq. [ LACM] ; Utinga tract, nr. Belem [ MCZC] . Ecuador. Napo: Jatun Sacha 7k ESE Pto. Misahualli [ PSWC] . Paraguay. Canindeyú: Res.Nat.Bosque Mbaracayu, Jejuimi [ ALWC] . Peru. Huánuco: Monson Valley, Tingo Maria [ LACM] . San Martín: Davidcillo, 30k NNE Tarapoto [ PSWC] .

Worker measurements: (n = 9) HL 2.23-2.47, HW 1.86-2.10, SL 2.09-2.32, WL 3.08-3.97, FL 2.25-2.49, LHT 2.44-2.77, PL 0.93-1.07, PH 1.42-1.55, CI 0.82-.86, SI 1.10-1.16.

Worker diagnosis: A smaller species (WL <4.0mm) with a short antennal scape and a tall, rounded petiolar node. Head somewhat longer than broad (CI 0.82-.86); mandibles elongate-triangular and bearing 11-13 teeth. Antennal scape shorter than head length. Posterolateral margins of propodeum rounded. Posterior and lateral faces of petiole meeting at an indistinct angle. Petiolar node conical and relatively tall (PH> 1.4 mm). Abdominal tergite 3 and usually also abdominal tergite 4 lacking erect setae. Hypopygium densely punctate-pubescent posteriorly, pubescence subdecumbent and covering integument(Fig. 8). Body and appendages dark brown to black; apical antennomeres and tarsomeres medium reddish-brown to dark brown.

This species may be readily separated from apicalis and veranae by the shorter antennal scapes.

Geographic variation: Specimens from the seven known localities appear remarkably uniform.

Distribution: Ecuador and northeastern Brazil to Paraguay.

Biology: Nearly all the information published under the name P. obscuricornis actually refers to P. verenae (see Discussion). Little is known about the biology of true P. obscuricornis . This rarely-encountered species appears to be a rainforest ant. The collection elevations run from around sea level to 700 meters. The records from San Martín Peru and Santa Cruz Bolivia are from rainforest, the Paraguayan specimens were collected as ground foragers in primary humid subtropical tall forest, and the Ecuadorian record is from the edge of a second growth rainforest. The single nest series, collected by Phil Ward in Davidcillo, 30 km NNE Tarapoto in San Martín, Peru, was in a rotting log.