Rasopone conicula

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Rasopone conicula
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Rasopone
Species: R. conicula
Binomial name
Rasopone conicula
(Mackay, W.P. & Mackay, E.E., 2010)

From Mackay and Mackay (2010): Specimens are occasionally collected in leaf litter extractions (rain forest, bamboo). The nest in Colombia was collected under a stone in red-yellow clay soil. Baena (1993) reported a specimen collected in a rotten log (listed as Rasopone pergandei), suggesting that logs may be the normal nesting sites.

Identification

From Mackay and Mackay (2010): The small round propodeal spiracle would separate Pachycondyla conicula from most species of Pachycondyla. The lateral margins of the pronotum of P. conicula are without a carina, which would distinguish this species from the widespread Rasopone arhuaca, the Venezuelan Neoponera emiliae and the Brazilian Neoponera metanotalis. Pachycondyla conicula could be easily confused with Rasopone becculata, which is also small, has a clypeal carina and has a depression at the metanotal suture. Pachycondyla conicula can be separated as R. becculata has a sharp point on the anterior medial border of the clypeus, not rounded or slightly concave as it is P. conicula. The relatively short medial tibia (shorter than the maximum width of the pronotum, about 1 mm in length) of P. conicula would separate this species from other similar species such as Mayaponera constricta, Neoponera rostrata, and Neoponera procidua. Pachycondyla conicula could be especially confused with M. constricta, but can be separated as the metanotal suture is not as deeply impressed. Pachycondyla conicula can be separated from the normally dark reddish brown Rasopone ferruginea by the relatively larger eyes (maximal diameter of the eye of R. ferruginea is 0.15 mm), much less than the distance between the anterior border of the eye and the anterior border of the head.

This new species has been misidentified as Rasopone pergandei, but differs in the shape of the petiole, which is narrowed towards the apex with a poorly defined dorsal face (not with nearly parallel faces and a well defined dorsal face as in R. pergandei), relatively short antennal scape that fails to reach the posterior lateral corner (extends past the posterior lateral corner of the head in R. pergandei) and a normal mesonotum (shortened in R. pergandei). Pachycondyla conicula could be easily confused with the smaller Ecuadorian Rasopone cernua. It can be easily separated as it lacks the ventrally directed angle on the posterior edge of the subpetiolar process as well as the longitudinal depression in the middle of the clypeus and the longer scapes, which extend approximately the first funicular segment past the posterior lateral corner of the head in R. cernua. The unusual coloration is present in nearly all of the males of P. conicula and R. pergandei and would separate the males of these two species from all of the others in the genus. The males of P. conicula can be separated from those of R. pergandei by the shape of the clypeus when viewed in profile. The surface is essentially flat in P. conicula, but abruptly lowers posteriorly, which gives it the appearance of a posterior bump. In R. pergandei the clypeal surface is convex and rounded, not forming a relatively flat surface and not abruptly lowered posteriorly.

Additionally the posterior part of the head is broadly rounded in P. conicula, not oval - shaped as in R. pergandei. Males of P. conicula can be separated from the tiny males of R. cernua as they lack the ventrally directed tooth on the subpetiolar process. Additionally the mesopleuron of P. conicula is relatively smooth and glossy, not roughly sculptured as in R. cernua.

Distribution

COLOMBIA, PERU, VENEZUELA (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists

Neotropical Region: Colombia, Peru, Venezuela (type locality).

Check distribution from AntMaps.

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Rasopone conicula for further details

Habitat

This species has been collected in the rain forest, transitional montane forest and secondary rain forest, at elevations ranging from 300 - 1500 meters. (Mackay and Mackay 2010)

Biology

Castes

Nomenclature

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

  • conicula. Pachycondyla conicula Mackay & Mackay, 2010: 264, figs. 49, 50, 196, 199, 323, 391-397 (w.q.m.) VENEZUELA. Combination in Rasopone: Schmidt & Shattuck, 2014: 210.

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

Description

Worker

Workers of Pachycondyla conicula are moderately small (total length about 8 mm) black ants with reddish brown appendages. The clypeus has a longitudinal medial raised area, but the region anterior to the eye is without a malar carina. The eye is relatively small (0.25 mm maximum diameter) which is longer than the distance between the anterior border of the eye and the anterior border of head (side view). The scape extends to the posterior lateral corner of the head. The overall dorsum of the mesosoma is convex, but is distinctly impressed at the promesonotal suture and is more deeply impressed at the metanotal suture and the mesonotum is developed, although poorly. The propodeal spiracle is circular and relatively small (diameter of the opening is 0.04 mm). The dorsal face of the propodeum is broadly rounded into the posterior face. The petiole is relatively narrow when viewed in profile with a vertical anterior face and a curved convex posterior face that meet at a moderately sharp apex. The anterior face of the postpetiole is vertical and straight and meets the dorsal face at an angle. The metasternal process consists of two well-developed triangular lobes.

Erect hairs are mostly short (0.15 - 0.25 mm) and present on most surfaces, including the dorsal and ventral surfaces of the head, the sides of the head, the scapes, the dorsum of the mesosoma, the legs, the dorsum of the petiole and all surfaces of the gaster. Appressed golden pubescence is abundant on nearly all surfaces.

Most surfaces are dull and punctate, except for the mandibles, which are finely striate and the coxae, which are partially punctate.

Queen

The female is a small (total length 6.5 mm) dark reddish brown specimen with ferrugineous red appendages. The mandibles have 13 or 14 teeth, which alternate in size with the apicalmost tooth being more than twice as long as any of the other teeth and basalmost teeth small and poorly developed. The anterior margin of the clypeus is broadly convex and the medial part of the clypeus appears to be "pinched" and raised to a higher level than the remainder of the clypeus. The head length is 1.65 mm; the head width is 1.55 mm. The greatest eye diameter is 0.36 mm and the eye is located less than ½ of its diameter from the anterior margin of the head. The sides of the head are weakly convex and nearly parallel, the posterior margin is distinctly concave. The ocelli are relatively small, the diameter of the median ocellus is 0.08 mm, slightly larger than the lateral ocellus (0.06 mm). The scape (1.3 mm) extends slightly past the posterior lateral margin of the head. The pronotal shoulder is slightly swollen, but does not form a carina. The propodeal spiracle is circular. The petiole is relatively narrow when viewed in profile with a nearly straight anterior face and a convex posterior face, both narrowed towards the apex and forming a sharply rounded apex.

Erect hairs are present on the mandibles, clypeus, dorsal surface of the head, sides of the head, along the posterior margin, on the entire shaft of the scape, on the ventral surface of the head, the dorsum of the mesosoma and all surfaces of gaster. Fine appressed golden pubescence is present on the head, the mesosoma and is slightly more abundant on the gaster.

The mandibles are striate and the dorsum of the head is densely and evenly punctate. The punctures on the mesosoma are finer than those on the head and the sides of the mesosoma are punctate, or very finely striolate. The petiole and the gaster are weakly to moderately shining.

Male

The male is a small (the head, mesosoma and petiole are 4 mm in length, the gaster is missing in the only available specimen) dark reddish brown specimen with yellow legs, mandibles and palps and a ferrugineous red pronotum and scutum. The mandibles are tiny but have a well-developed depression near the base, which occupies approximately ½ of the surface. The anterior margin of the clypeus is broadly convex, in profile the surface of the clypeus is raised into a flattened surface, which is abruptly lowered near the posterior edge, making that region appear to have a bump. The head length is 1.05 mm; the head width is 0.93 mm. The maximum diameter of the eye is 0.53 mm, located nearly one diameter from the lateral ocellus. The median ocellus is 0.10 mm diameter, located about one diameter from the lateral ocellus (diameter 0.09 mm). The head is narrowed anteriorly and the posterior half of the head is broadly rounded. The propodeal spiracle is nearly circular in shape. The petiole is moderately thickened with the anterior and posterior faces being nearly straight and forming a broadly rounded apex. The subpetiolar process cannot be seen well enough to describe.

Erect hairs are sparse with a few on the posterior edge of the head, on the mesosoma and on the petiole, most surfaces are covered with a plush of fine golden hairs. The head is finely punctate and slightly shining. The sculpture on the mesosoma consists of finer punctures and at least some of the surfaces, especially the side of the pronotum and mesopleuron are moderately shining. The propodeum is mostly sculptured and has poorly defined striolae. The petiole is finely sculptured, but only weakly shining.

Type Material

Estado Aragua, Rancho Grande, 23-27 June, 1100 m, rainfor.; VENEZUELA. Holotype worker (Museum of Comparative Zoology), 14 paratype workers (California Academy of Sciences, CWEM, IAVH, Los Angeles County Museum of Natural History, MIZA, Museu de Zoologia da Universidade de Sao Paulo, MCZC, National Museum of Natural History), 1 paratype female (MCZC) and one paratype male (MCZC).

Etymology

From Latin, coniculus, meaning cone, referring to the shape of the petiole.

References

  • Baena, M. L. 1993. Hormigas cazadoras del género Pachycondyla (Hymenoptera: Ponerinae) de la Isla Gorgona y la planicie Pacifica Colombiana. Boletin. Del Museo. Entomológica de la Universidad del Valle 1:13-21.
  • 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.
  • Schmidt, C.A. & Shattuck, S.O. 2014. The higher classification of the ant subfamily Ponerinae (Hymenoptera: Formicidae), with a review of ponerine ecology and behavior. Zootaxa. 3817, 1–242 (doi:10.11646/zootaxa.3817.1.1)