Octostruma petiolata

Nothing is known about the biology of .

Identification
This species is known from southern Brazil. Workers can be identified by the combination of strongly transverse petiolar node in dorsal view, mesosoma lacking erect setae, large size (HW 0.85–0.90), and strong laminar transverse carina joining the propodeal spines. I examined a worker from Itajubá, Santa Catarina State (MCZ). (Longino 2013)

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  petiolata. Rhopalothrix petiolata Mayr, 1887: 580 (q.) BRAZIL. Emery, 1894c: 217 (w.). Combination in Octostruma: Brown, 1949f: 92. See also: Brown & Kempf, 1960: 182.

Worker
Brown and Kempf (1960) - 6 specimens, from two different localities): TL 3.3-3.5, HL 0.74-0.78, HW 0.85-0.90 (CI 114-117), WL 0.89-0.92 mm.

Queen
Brown and Kempf (1960) - Alate (3 specimens, including 2 syntypes): TL 5.2-5.5, HL 0.98-1.00, HW 1.14-1.20 (CI 116-120), WL;.45-1.53, forewing L 4.7-5.1 mm.

This species, described from the female caste, has workers so different in habitus, and especially in sculpture and ground pilosity, that only examination of the workers and female associated by Emery (lac. cit.) from "5. Paulo" (von Jhering leg.) finally convinced us that they belong together. Curiously, Emery's characterization of the worker does not bring out the outstanding differences. In addition to the size and head form differences, the worker has the head, alitrunk and both nodes very minutely and superficially shagreened, so that the surface is smooth but opaque. The gaster is more lightly -shagreened and is weakly shining to subopaque, with feeble punctulation over the surface. The female has the head and pronotum distinctly vermiculate-rugulose; scutum longitudinally subcostulate and shallowly punctate; scutellum transversely rugulose. The nodes are shagreened, with weak punctation, and the gaster is densely and finely punctate and opaque. The alitrunk is very convex, both from front to rear and from side to side in the worker; the dorsal sutures are absent in the two worker specimens seen, but the dorsum of the propodeum forms a slight angle with the promesonotum where they join. Propodeal teeth short and triangular in both female and worker. The six workers seen had the erect clavate hairs confined to the head, scapes, legs and gastric apex and venter, but the dorsal surfaces of the body, except the upper central part of the head, have abundant fine appressed hairs. A pair of fine long hairs anteromedially on first gastriC sternite. The female has, in addition to the rather abundant appressed ground pilosity and erect clavate hairs of head and gastric apex, a few slender clavate hairs on the scutum, many on the gastric venter, and two irregular longitudinal groups of about 8 hairs each on each side of the gastric midline.

Type Material
Longino (2013) - Holotype queen: Brazil, Santa Catarina NMW? (not examined).

References based on Global Ant Biodiversity Informatics

 * Brown W. L., Jr., and W. W. Kempf. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250.
 * Emery C. 1894. Studi sulle formiche della fauna neotropica. VI-XVI. Bullettino della Società Entomologica Italiana 26: 137-241.
 * Kempf W. W. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Longino J. T. 2013. A revision of the ant genus Octostruma Forel 1912 (Hymenoptera, Formicidae). Zootaxa 3699(1): 1-61.
 * Luederwaldt H. 1918. Notas myrmecologicas. Rev. Mus. Paul. 10: 29-64.
 * Medeiros Macedo L. P., E. B. Filho, amd J. H. C. Delabie. 2011. Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept. Revista Brasileira de Entomologia 55(1): 7578.
 * Probst R. S., B. D. Wray, C. S. Moreau, and C. R. F. Brandao. 2019. A phylogenetic analysis of the dirt ants, Basiceros (Formicidae: Myrmicinae): inferring life histories through morphological convergence. Insect Systematics and Diversity 3(4): 1–12.
 * Rosa da Silva R. 1999. Formigas (Hymenoptera: Formicidae) do oeste de Santa Catarina: historico das coletas e lista atualizada das especies do Estado de Santa Catarina. Biotemas 12(2): 75-100.
 * Rosumek, F.B., M.A. Ulyssea, B.C. Lopes, J. Steiner. 2008. Formigas de solo e de bromélias em uma área de Mata Atlântica, Ilha de Santa Catarina, sul do Brasil: Levantamento de espécies e novos registros. Revista Biotemas 21(4):81-89.
 * Silva R.R., and C. R. F. Brandao. 2014. Ecosystem-Wide Morphological Structure of Leaf-Litter Ant Communities along a Tropical Latitudinal Gradient. PLoSONE 9(3): e93049. doi:10.1371/journal.pone.0093049
 * Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-611.