Oxyepoecus kempfi

Oxyepoecus kempfi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Solenopsidini
Genus:	Oxyepoecus
Species:	O. kempfi
Binomial name
Oxyepoecus kempfi Albuquerque & Brandão, 2004

O. kempfi is known from the type locality and Milgras and Boa Vista in northeastern Brazil. The type was collected from sifted litter samples in “cerrado” (Brazilian savanna).

Identification

Albuquerque and Brandao (2004) - The exclusive character of the workers of O. kempfi is the minute size (t.l.), and the pattern of sculpture inside the frontal carinae.

Keys including this Species

• Key to Oxyepoecus species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -10.43333333° to -10.43333333°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Overview of Oxyepoecus biology  The following account is modified from Kempf (1974) and Albuquerque & Brandão (2009). Our knowledge of Oxyepoecus ants still rests exclusively on chance discoveries. Since about 95% of the known specimens were taken as strays in berlesates of forest floor cover, very little may be said about the biology of Oxyepoecus species except for being denizens or at least foragers in this particular habitat. The minute size of Oxyepoecus, their color and cryptic habits hamper direct observation of their habits in natural conditions (especially inside shaded forest where light rarely reaches the ground). Oxyepoecus has been considered very rare in collections, but our studies show that they are rather common in the leaf litter of most localities where recent surveys have been conducted in the Mata Atlântica (see Comments in Albuquerque & Brandão, 2004). It is interesting to note that one of these localities we recently surveyed, Cunha, São Paulo state has four Oxyepoecus species (Oxyepoecus myops, Oxyepoecus rastratus, Oxyepoecus longicephalus and Oxyepoecus rosai), three of which were found in one square meter of leaf-litter (sample 48; all but O. rosai). In Salesópolis, SP, we recorded five of the 17 known Oxyepoecus species (O. myops, Oxyepoecus punctifrons, O. rastratus, O. rosai and Oxyepoecus vezenyii). Both Cunha and Salesópolis are localities circa 1000 m above sea level, covered by pristine evergreen dense forest. Although Oxyepoecus samples come mostly from forested localities, workers have been less frequently collected in places with more open vegetation, as open “cerrados” (savannas). Comparing the examined material of most species, one can see that the specimens mostly come from the same localities. This is because these localities we surveyed recently, extracting ants from the leaf-litter, or localities where careful collectors lived most of their lifes (Seara, SC, for instance, where F. Plaumann worked many years). Kusnezov (1952) put forward the hypothesis that Oxyepoecus ants are inquilines of Pheidole and Solenopsis nests. Evidence exists for their being symbiotic relationships between several Oxyepoecus species and other Myrmicinae ants (details provided here). Independent colonies seem to be vouched for by Oxyepoecus punctifrons and Oxyepoecus rastratus. The types of the former, collected at Rio Negro, Paraná State, Brazil, came from a nest that had over 60 workers living by themselves, but no further information is available. A few workers of the same species, at Campos do Jordão, São Paulo State, Brazil, were also found on a dead twig, between the bark and an overgrown cover consisting of lichens and mosses. The types of the var. luederwaldti (= rastratus) are from a very small colony nesting under the bark in a simple cavity within the alburnum of a tree (Luederwaldt, 1926: 275). Lenko's rastratus specimens from Caraça, Minas Gerais State, had their nest within a decaying log on the ground in a forest. A similar nesting situation was found from a more recent collection from Paraguay (col A. Wild). The fact that Oxyepoecus workers are relatively abundant in material extracted from leaf litter samples, while dealate gynes are seldom found in the litter and larvae have never been found in litter samples, suggests that they nest in the soil, where the gynes and larvae live, but workers leave the nest periodically to search for food. Oxyepoecus has been attracted to honey or sardine baits set over the ground in different habitats, which suggests they are generalist foragers. In just one case, a gyne and two workers of O. punctifrons (Vezenyii group) were found by Rogerio R. da Silva under the bark of a the canopy branch in a recently fallen Leguminoseae (Albuquerque & Brandão, 2004).

Castes

Known only from the worker caste.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

• kempfi. Oxyepoecus kempfi Albuquerque & Brandão, 2004: 67, figs. 3a-c (w.) BRAZIL.

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

Description

Worker

Holotype and paratype within brackets t.l.= 1.71 (1.77); h.l.= 0.45 (0.46); h.w.= 0.35 (0.37); s.l.= 0.21 (0.23); m.l.e.= 0.10 (0.10); m.w.pr.= 0.32 (0.31); a.l.= 0.49 (0.52); h.f.l.= 0.26 (0.28); m.w.p.= 0.18 (0.21); m.w.pp.= 0. 21 (0. 22); c.i. 78 (80). Color reddish brown. Integument smooth and shining, with the following exceptions: posterior area between frontal carinae longitudinally faintly striate, the striations prolong caudad and obliquely laterad, reaching the level of the superior orbit of the compound eyes; genae with few vestigial rugae that reach the inferior orbit of the compound eyes; dorsal disc of pronotum with piligerous punctuations; posterior area of the katepisternum, and whole metapleuron longitudinally costulate, the costulae prolonged to the bulla of the metapleural gland; the dorsal face of the propodeum with 6-8 transverse curved costulae. Hairs moderately abundant, long, suberect and relatively curved on mesosoma, petiolar node with some subdecumbent and suberect hairs; some decumbent hairs on the postpetiole.

Head, mandibles elongate, with a broad and relatively shallow diastema between the basal and the subbasal tooth, and also a slightly larger diastema between the subbasal tooth and the subapical. Anterior teeth of the clypeus with lateral denticles, better seen when the clypeus margin is in oblique view. Frontal carinae relatively short, concave behind the antennal sockets, reaching the level of the inferior orbit of the compound eyes, the maximum width between their outer edges approximately 2/5 of the head width. Compound eyes small, with about 5-6 facets r.g.d., which is less than the distance between the inferior orbit and the mandibular insertion: total number of ommatidia about 18. Antennal scape failing to reach the occipital corner by a distance larger than the maximum thickness of the scape. Funicular segment I as long as II-IV combined, segments II-VII distinctly broader than long, VIII and IX as long as broad.

Mesosoma. Shoulders not at all marked, sides of the pronotum rounded, but the dorsal and lateral faces clearly distinguished. Metanotal groove not impressed (p.v.). Dorsal face of the propodeum immarginate on sides; posteriorly with two acute and prominent spines. Declivous face laterally marginate, the margin as weak carinae.

Petiole node high and round, slightly higher than the postpetiole, antero-posteriorly compressed and a little expanded laterally, almost 2/3 of the postpetiole width (d.v.); subpetiolar process minute, subquadrate, followed by one posterior very small denticle. The postpetiole very broad, in a scalelike fashion, subpostpetiolar process small with two subparallel crests of similar size, but curved forwards.

Type Material

Holotype worker, Brasil: Piauí: Corrente [10°26’S 45°09’W], 23-27.xi.1991, C.R.F. Brandão [col.], deposited in Museu de Zoologia da Universidade de Sao Paulo. Paratype: same data as holotype. Both specimens were broken while being examined, the postpetiole and gaster were glued in the same paper triangle of the respective head and mesosoma.

Etymology

In memory of the Brazilian myrmecologist Walter W. Kempf; an inspiration to the study of this genus.

References

• Albuquerque, N.L.d., Brandão, C.R.F. 2004. A revision of the Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 1. The Vezenyii species-group. Papéis Avulsos de Zoologia (São Paulo). 44: 55-80 (doi:10.1590/S0031-10492004000400001).
• Albuquerque, N.L.d., Brandão, C.R.F. 2009. A revision of the Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae): 2. Final. Key for species and revision of the Rastratus species-group. Papéis Avulsos de Zoologia (São Paulo). 49: 289-309 (doi:10.1590/S0031-10492009002300001).

References based on Global Ant Biodiversity Informatics

• Ulyssea M. A., C. R. F. Brandao. 2013. Catalogue of Dacetini and Solenopsidini ant type specimens (Hymenoptera, Formicidae, Myrmicinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papies Avulsos de Zoologia 53(14): 187-209.