Wadeura holmgreni

Little is known about the biology of this species.

Identification
Mackay and Mackay (2010): The worker of W. holmgreni is nearly identical to that of Cryptopone gilva. It differs in having larger mandibles with more teeth, having a tooth on the medial border of the clypeus, not having a slightly depressed dorsal propodeal face as compared to the level of the mesonotum and lacking the translucent anterior half the subpetiolar process. Wadeura holmgreni can be separated from Centromyrmex brachycola by having most surfaces dull or only weakly shining, not smooth and glossy as in W. holmgreni.

Distribution
PERÚ, TRINIDAD, GUIANAS, BRASIL (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, French Guiana, Guyana, Peru, Suriname.

Habitat
This species has been collected in mature montane rainforest, between 550 - 650 meters. (Mackay and Mackay 2010)

Biology
Wadeura are rarely collected, which is why there is sparse natural history information and sociometry data for species in this genus. Myrmecological sampling methods do not capture hypogeic ants very well. It takes soil samples collected for earthworm diversity studies (Fernandes and Delabie, 2019, Macoupa, French Guiana), for example, to find that Wadeura guianensis and Wadeura holmgreni can live in sympatry.

Nomenclature

 * . Euponera (Trachymesopus) holmgreni Wheeler, W.M. 1925a: 6 (w.) PERU.
 * Type-material: 2 syntype workers.
 * Type-locality: Peru: (no further data) (N. Holmgren).
 * Type-depositories: MCZC, NHRS.
 * Combination in Trachymesopus: Kempf, 1960f: 424;
 * combination in Pachycondyla: Brown, in Bolton, 1995b: 306;
 * combination in Cryptopone: Schmidt, C.A. & Shattuck, 2014: 185;
 * combination in Wadeura: Branstetter & Longino, 2022: 19.
 * Status as species: Kempf, 1961b: 494 (redescription); Kempf, 1972a: 251; Mackay & Mackay, 2010: 390 (redescription); Bezděčková, et al. 2015: 123; Feitosa, 2015c: 98 Fernandes & Delabie, 2019: 411; Branstetter & Longino, 2022: 19.
 * Distribution: Brazil, Peru, French Guiana, Suriname, Trinidad.

Worker
Mackay and Mackay (2010): The worker is a small (4.5 mm total length) pale brown specimen. The mandible apparently has seven teeth (four basalmost teeth and an apical tooth well defined, the other two located between the four basal teeth and apical tooth and are poorly defined). The mandible has a depressed region near the base followed by a short (0.1 mm) furrow. The anterior border of the clypeus is slightly concave medially with a small raised medial tooth along a poorly defined longitudinal carina. The head length is 0.92 mm; the head width is 0.89 mm. The head is narrowed anteriorly and the posterior margin is concave. The eye is apparently absent. The scape (0.58 mm) extends to within the first two funicular segments of the posterior lateral corner of the head. The dorsum of the mesosoma is nearly straight and the metanotal suture is poorly developed. The pronotal shoulder is without a carina.

The propodeal spiracle is circular-shaped. The petiole is thickened when viewed in profile. The anterior face is 0.28 mm in length, the dorsal face is 0.23 mm in length and the posterior face is 0.16 mm in length. The anterior face is nearly vertical, the dorsal and posterior faces form a broadly rounded surface. The sub-petiolar process consists of a swollen nearly angulate anterior process, which gradually diminishes in width posteriorly. The second pretergite is not visible.

The clypeus has several moderately long (up to 0.24 mm in length) erect hairs. The dorsal surface of the head is covered by an abundance of bristly short (0.06 mm in length) erect hairs. The ventral surface of the head has a few long (0.08 - 0.28 mm) erect hairs. The dorsum of the mesosoma has several erect hairs (0.06 - 0.12 mm). The hairs on the dorsum of the petiole, on the subpetiolar process and all surfaces of the gaster are similar to those on the mesosoma. The legs have a few erect hairs. The middle tibia has a number of coarse setae on the extensor surface.

The mandibles are smooth and glossy with scattered punctures. The head and mesosoma are very finely but densely punctate and dull. The sculpture on the petiole and gaster is finer and the surfaces are moderately smooth and shining.

Type Material
Perú. Holotype worker seen, designator unknown,, 2 specimens were listed in description (Mackay and Mackay 2010)

Etymology
This species is named in honor of Mr. N. Holmgren, who collected the type series. (Mackay and Mackay 2010)

References based on Global Ant Biodiversity Informatics

 * Escalante Gutiérrez J. A. 1993. Especies de hormigas conocidas del Perú (Hymenoptera: Formicidae). Revista Peruana de Entomología 34:1-13.
 * Fernandes I. O., and J. H. C. Delabie. 2019. A new species of Cryptopone Emery (Hymenoptera: Formicidae: Ponerinae) from Brazil with observations on the genus and a key for New Word species. Sociobiology 66(3): 408-413.
 * Fernández F., and T. M. Arias-Penna. 2008. Las hormigas cazadoras en la región Neotropical. Pp. 3-39 in: Jiménez, E.; Fernández, F.; Arias, T.M.; Lozano-Zambrano, F. H. (eds.) 2008. Sistemática, biogeografía y conservación de las hormigas cazadoras de Colombia. Bogotá: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, xiv + 609 pp.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Groc S., J. H. C. Delabie, F. Fernandez, M. Leponce, J. Orivel, R. Silvestre, Heraldo L. Vasconcelos, and A. Dejean. 2013. Leaf-litter ant communities (Hymenoptera: Formicidae) in a pristine Guianese rainforest: stable functional structure versus high species turnover. Myrmecological News 19: 43-51.
 * Jacquemin J., T. Drouet, T. Delsinne, Y. Roisin, and M. Leponce. 2012. Soil properties only weakly affect subterranean ant distribution at small spatial scales. Applied Soil Ecology 62: 163-169.
 * Kempf W. W. 1960. Miscellaneous studies on Neotropical ants (Hymenoptera, Formicidae). Studia Entomologica (n.s.)3: 417-466.
 * Kempf W. W. 1961. A survey of the ants of the soil fauna in Surinam (Hymenoptera: Formicidae). Studia Entomologica 4: 481-524.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * 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
 * Wheeler W. M. 1925. Neotropical ants in the collections of the Royal Museum of Stockholm. Arkiv för Zoologi 17A(8): 1-55.