Pachycondyla lattkei

From Mackay and Mackay (2010): The nest of the type series was collected under a log. The soil was red and yellow clay. Two males (October), but no females were collected. The specimens from Aragua, Venezuela were collected in pitfall traps.

Identification
From Mackay and Mackay (2010): Pachycondyla lattkei is nearly identical to Pachycondyla impressa. The workers can be easily distinguished by the glossy gaster, a character that can be seen in the field or on pinned specimens without the aid of a microscope. Additionally the pygidium of P. lattkei is not depressed (as in P. impressa) and the striae on the dorsum of the pronotum are predominantly longitudinal, not predominantly transverse as in P. impressa. The metasternal process of P. lattkei has widely spaced lobes (generally the tips are more than 0.3 mm apart, generally less than 0.3 mm in P. impressa) and the inner tooth is absent (present in P. impressa).

The shiny gaster of P. lattkei could cause confusion with the Colombian (and presumably Venezuelan) Pachycondyla fuscoatra, which also has a shiny gaster. They can be easily separated as P. lattkei lacks the coarse striae on the head and the anterior face of the petiole is not concave as it is in P. fuscoatra.

The relatively short clypeus of P. lattkei suggests a close relationship with P. impressa and will allow it to be distinguished from the other members of the crassinoda species complex (especially Pachycondyla inca and Pachycondyla purpurascens).

The males of three species are very similar: P. lattkei, Neoponera villosa and Pachycondyla striata. Pachycondyla lattkei can be separated from the other two by the presence of the irregular rugae on the petiole (lacking in the other two species). The subpetiolar process of P. lattkei is broadly rounded, not angulate as in the other two species. The erect hairs are sparse in P. lattkei as compared to those of P. striata. The male of P. impressa has a more sculptured gaster. The clypeus of P. lattkei lacks the concave anterior margin, which is found in P. impressa.

An unidentified male near P. lattkei, possibly the unknown male of Pachycondyla crassinoda, was collected in Quincemil, Peru. It differs from P. lattkei in lacking the rugae on the side of the propodeum but has similar rugae on the side of the petiole. The subpetiolar process is concave, differing from P. lattkei, but similar to that found in males of the crenata species complex. The anterior margin of the clypeus is concave, similar to that of P. lattkei, but is concave across the entire border and not just medially as in the male of P. lattkei.

Distribution
VENEZUELA (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists
Neotropical Region: Venezuela.

Habitat
Pachycondyla lattkei was collected in second growth rain forest to thick cloud forest. (Mackay and Mackay 2010)

Nomenclature

 *  lattkei. Pachycondyla lattkei Mackay & Mackay, 2010: 424, figs. 17, 58, 63, 251, 296, 549-552 (w.m.) VENEZUELA.

Worker
The worker is a moderately large (total length 11-12 mm) ant with a shiny gaster. The mandible has ten teeth. The anterior margin of the clypeus is concave medially. The head is 2.9 mm in length and 2.9 mm in width. The malar carina is absent, the eye is relatively small (maximum diameter 0.44 mm) and is located approximately one diameter from the anterior edge of the head (side view). The sides of the head are nearly parallel but are narrowed anteriorly, the posterior margin is concave. The scape (2.45 mm in length) extends to the posterior margin of the head. The pronotal shoulder lacks a carina but is slightly swollen, the promesonotal suture is depressed on the dorsum of the mesosoma, but the metanotal suture is barely evident. The propodeal spiracle is slit-shaped. The petiole is thick when viewed in profile with the anterior and posterior faces being nearly parallel (side view) and with a well formed horizontal dorsalface. The subpetiolar process is well developed and consists of a swollen lobe, which is slightly angulate anteriorly. The stridulatory file is absent on the second tergum and the arolia are absent between the tibial claws.

Erect hairs are abundant on most surfaces, including the mandibles, dorsal and ventral surfaces of the head, the antennal scape, posterior margin of the head, the dorsum of the mesosoma, the hairs on the legs are mostly suberect, erect hairs are present on the dorsal and ventral surfaces of the petiole and all surfaces of the gaster. Appressed pubescence is sparse with a few hairs noticeable on the head, dorsum of the mesosoma, the dorsum of the petiole and all surfaces of the gaster.

The mandibles are mostly smooth with scattered punctures and with some evidence of fine striae, the dorsum of the head is punctate with the punctures in rows and forming poorly defined striae, most of the striae on the pronotum are longitudinal, although those on the neck are transverse and extend posteriorly along the side of the pronotum, the mesopleuron and propodeum have oblique longitudinal striae, longitudinal striae on the mesonotum and dorsum of the propodeum are mostly longitudinal, but those on the posterior face of the propodeum are horizontal joining with the striae on the side of the propodeum. The side of the petiole has horizontal striae, those on the posterior face of the node are finer and mostly transverse and forming concentric arches, the striae on the dorsum of the petiole are mostly transverse. All surfaces of the gaster are smooth and glossy with a little evidence of scattered very fine punctures.

Queen
Queens are not known for this species.

Male
The male is also large (total length 16 mm). The surface of the clypeus is convex but does not form a rounded lobe (side view). The head is 1.76 mm in length; the head width is 1.80 mm. The scape is short (0.36 mm). The eye is relatively small (maximum diameter 0.94 mm) the diameter is approximately equal to the distance from the top of the eye to the medial point of the head (side view). The ocelli are relatively small (maximum diameter 0.18) located more than one diameter from the adjacent ocelli. The propodeal spiracle is slit-shaped. The petiole is narrowed toward the apex, not rectangular-shaped as in the worker. The subpetiolar process is similar to that of the worker, but the sides are concave and the sharp anterior tooth is absent.

Erect hairs are abundant on most surfaces as in the worker; those on the petiole are slightly curled. Appressed golden hairs are thick (and matted on specimens that had been in alcohol) and are present on the head, mesosoma, petiole and gaster.

The head is finely punctate and weakly shining; the mesosoma and petiole are covered with coarse irregular reticulate rugae, which gives the surface a hammered appearance. The gaster is as smooth and glossy as that of the worker.

The specimen is concolorous black.

Type Material
VENEZUELA, D. F., Parque Vinicio Adames. Holotype worker, 18 paratype workers , 2 paratype males

Etymology
Named in honor of our close friend and fellow “mirmecólogo”, John Lattke, headquartered in Venezuela and authority on ants, especially those of the Neotropics.

References based on Global Ant Biodiversity Informatics

 * Mackay, W.P. and E.E. MacKay. 2010. The systematics and biology of the New World ants of the genus Pachycondyla (Hymenoptera: Formicidae). Edwin Mellen Press Lewiston, NY