Octostruma balzani

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Octostruma balzani
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Octostruma
Species: O. balzani
Binomial name
Octostruma balzani
(Emery, 1894)

Octostruma balzani casent0178000 profile 1.jpg

Octostruma balzani casent0178000 dorsal 1.jpg

Specimen labels

Synonyms

Octostruma balzani is a widespread Central and South American species that is common in many localities. It occurs in a variety of forested habitats: wet to seasonal dry, second growth to mature, lowland to montane. It usually occurs from sea level to the lower edges of cloud forests, typically around 1400 m. The highest elevation record is 1650 m in Nuevo León, Mexico. Almost all collections are from Berlese and Winkler samples of sifted litter and rotten wood from the forest floor. In quantitative 1 m2 litter plot samples, within-sample abundance is tens of workers or fewer, but the species can occur in nearly every sample, suggesting a high density of small colonies. Dealate queens and intercaste workers often occur together with workers in litter samples. (Longino 2013)

Identification

Keys including this Species

Distribution

Longino 1999 for what is called the balzani complex - Tropical Mexico south through Central and South America at low and moderate elevations to the Bolivian Andes and to Parana and Sao Paulo states in southeastern Brazil; Trinidad, Dominica, and probably other islands of the Lesser Antilles (Brown and Kempf 1960).

Latitudinal Distribution Pattern

Latitudinal Range: 29.95° to -64.36°.

       
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Belize, Bolivia (type locality), Brazil, Colombia, Costa Rica, Dominica, Ecuador, El Salvador, French Guiana, Greater Antilles, Guadeloupe, Guatemala, Guyana, Honduras, Jamaica, Lesser Antilles, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Venezuela.

Distribution based on AntMaps

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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.
pChart

Biology

Explore-icon.png Explore Overview of Octostruma biology 
Longino (2013) - Brown and Kempf (1960) summarized the biology of basicerotines as follows: The basicerotines all come from tropical or subtropical areas, and predominantly from mesic habitats, particularly rain forest, where they live primarily in the upper layers of the soil and in the soil cover, including large and small pieces of rotten wood. They are fairly common in soil cover berlesates. Nests have been found in snail shells, and in the peaty masses gathered about epiphytic ferns above the ground level. So far as is known, colonies are small, consisting of one or more dealate—or rarely ergatoid—females, and a few workers. Judging from the structure of the workers and females, one would suppose that they were predaceous on small arthropods...

Besides this summary, the behavior of three basicerotine species has been studied. Wilson (1956) observed a small captive colony of Eurhopalothrix biroi, a New Guinea species. Workers moved slowly and captured a variety of small, soft-bodied prey, including spiders, symphylans, entomobryid Collembola, campodeids, and hemipteran nymphs. Wilson and Brown (1984) observed a captive colony of Eurhopalothrix heliscata, a species from Singapore. The colony contained over 400 workers, multiple alate and dealate queens, several adult males, and brood. Foraging workers acted "rather like miniature ferrets," readily wedging themselves into small crevices. They foraged solitarily, attacking a variety of prey but mostly termites. They used their sharply-toothed mandibles to abruptly snap onto appendages of prey, maintaining purchase and slowly reaching around with the gaster to sting the prey. The strongly sclerotized labrum was also employed to press against the clamped appendage. The behavioral repertoire was limited. There did not appear to be trophallaxis, as workers and larvae fed directly from prey in the brood chambers. Nor did there appear to be any form of alarm communication. While there was generally an increase in the number of foragers when clusters of prey were presented, there was no evidence of any pheromone-based recruitment. Workers were non-aggressive and responded to disturbance by tucking the appendages and becoming immobile, often for minutes at a time. Wilson and Hölldobler (1986) studied captive colonies of Basiceros manni from Costa Rica and observed behavior not substantially different from E. heliscata. Foraging workers of many basicerotines are often encrusted with a firmly bonded layer of soil, which is thought to function as camouflage, enhancing crypsis (Hölldobler & Wilson, 1986).

Knowledge of the basic natural history of these ants has hardly progressed since the observations of Wilson, Brown, and Hölldobler. More specimens are now available for examination due to quantitative litter sampling, enhancing knowledge of basicerotine diversity and distribution, but discovering nests remains exceedingly difficult. Quantitative samples of 1 m2 litter plots reveals that small basicerotines can be very frequent, occurring in over 50% of samples in some cases, but never in large numbers. Individual samples usually contain fewer than ten workers, and workers are often accompanied by dealate queens. These results suggest that colonies, at least among New World species, are usually small, with tens of workers.

Less than half of the species of Octostruma have their queens described. Ergatoid queens are known from some species. Males are known from collections for some species but none have been described. The mating biology of these ants and how common ergatoid queens are across the genus and within colonies is not known. ‎

Castes

Worker

Images from AntWeb

Octostruma balzani casent0178665 head 1.jpgOctostruma balzani casent0178665 profile 1.jpgOctostruma balzani casent0178665 dorsal 1.jpgOctostruma balzani casent0178665 label 1.jpg
Worker. Specimen code casent0178665. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MIZA, Maracay, Venezuela.

Queen

Images from AntWeb

Octostruma balzani casent0178001 head 1.jpgOctostruma balzani casent0178001 profile 1.jpgOctostruma balzani casent0178001 dorsal 1.jpgOctostruma balzani casent0178001 label 1.jpg
Queen (alate/dealate). Specimen code casent0178001. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by ALWC, Alex L. Wild Collection.

Nomenclature

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

  • balzani. Rhopalothrix balzani Emery, 1894c: 217, pl. 1, fig. 10 (w.q.) BOLIVIA. Combination in Octostruma: Brown, 1949f: 92. Senior synonym of barberi, equilatera: Brown & Kempf, 1960: 194.
  • barberi. Rhopalothrix (Octostruma) barberi Mann, 1922: 42 (w.) GUATEMALA. Combination in Octostruma: Brown, 1949f: 92. Junior synonym of balzani: Brown & Kempf, 1960: 194.
  • equilatera. Rhopalothrix (Octostruma) equilatera Weber, 1934a: 52, fig. 10 (w.) NICARAGUA. Combination in Octostruma: Brown, 1949f: 92. Junior synonym of balzani: Brown & Kempf, 1960: 194.

Description

Worker

Ferrugineo fusca, antennis pedibusque rufescentibus, vel tota ferruginea, opaca, creberrime punctata, capite lato, absque crista transversa, scapo valde dilatato, angulo basali subloformi, thorace convexo, sutra meso-metanotali distincta, metanoto spinis trigonis armato, pedunculi segmento 1° postice superne nodo parum latiore quam longiore. Long. 1 3/4 mm.

Brown and Kempf (1960) - TL 1.9-2.7, HL 0.48-0.58, HW 0.51-0.65 (CI 101-113), WL 0.50-0.65 mm; measurements based on 42 workers representing at least 18 separate nests from all parts of the range, including the holotype worker: HL 0.56, WL 0.60 mm, CI 102; head narrower than average for this species.

The general form of the head and alitrunk and petiole varies within limits individually and among different nest series. Occiput convex and anterior part of cephalic dorsum flat or shallowly concave; the meeting of these two surfaces often produces a feebly indicated, blunt ridge or rise crossing the head in an arc and corresponding to the carina found in rugifera and rugiferoides. Lateral occipital (postocular) angles obtuse to obsolete.

Mandibles of moderate length, their upper surfaces feebly convex, external margins weakly convex in outline; masticatory border and teeth very slightly depressed; usually 7 larger teeth, with 2-3 minute intercalary denticles. Basal tooth most commonly broad and bluntly rounded or subtruncate, filling or nearly filling the space between mandibles and clypeus at full closure. In occasional specimens from the northern part of the range (thus away from the range of the sibling O. stenognatha), the basal tooth is variably narrowed to a blunt point, but never to the extent of stenognatha. The compound eyes vary in size from small to very small, apparently allometrically corresponding to degree of gynecoidy.

Alitrunk often more convex above in outline; metanotal groove varying from reasonably distinct, or more feeble, to virtually obsolete on the dorsum. Propodeal teeth also somewhat variable in size and shape. Petiolar node varying to a much more rounded summit profile; as seen from above, node proper about twice as long as broad in most samples, rectangular. Postpetiole subreniform, broader than petiole (but not twice as wide) and about half or a little more as wide as the first gastric segment.

The stubby erect clavate hairs vary considerably in number present; the pattern is a common one, allowing for hairs broken off. Additional pairs of hairs added on head, alitrunk, postpetiole and gastric dorsum commonly accompany increase in size, and apparently represent a gynecoidal tendency. The alitrunk may have no erect hairs, but often 1, 2, or even as many as 3 pairs are present. On the dorsum of the first gastric segment, the number of hairs is usually between 6 and 12, but may reach as high as 20 or more, mostly concentrated on the posterior 2/3 of the segment in rows of 4 or 6. Ground hairs are generally appressed or reclinate and inconspicuous, but in some samples they are easily seen, though appressed, on clypeus, anterior part of head or gastric dorsum, or all three places. Sculpture densely and regularly punctulate. prevailingly opaque. Color varying shades of reddish-brown.

Queen

Caput et antennae fere ut in worker, spinae metanoti validiores, petioli nodus 1. superne trapezoideus, antice latior quam postice, circiter dimidio latior quam longior. Alae fuscatae. Long. 2 mm.

Brown and Kempf (1960) - Ergatoid females (gynecoid workers) are like the worker, but are larger and have ocelli. The alitrunk is proportionately a little longer, and sometimes the promesonotal suture is better-developed; erect hairs are more numerous and widely distributed. Female: TL 2.7-3.0, HL 0.58-0.63, HW 0.62-0.65 (CI 100-109), WL 0.75-0.80 mm (8 specimens from 5 localities).

Type Material

Brown and Kempf (1960) - Type localities: Districts of Coroico and Chulimani-Yungas, Bolivia; other locality, Salinas sul Beni, Bolivia. Types in Museo Civico di Storia Naturale, Genoa; worker from Coroico examined and here designated as lectotype.

Rhopalothrix (Octostruma) lutzi Wheeler, 1913. Bull. Amer. Mus. Nat. Hist., 32: 241, worker, female (part.). Type localities: Laudet and Long Ditton, near Roseau, Dominica, B.W.I. Lectotype, by present designation, the specimen (Long Ditton) so labelled in Museum of Comparative Zoology, examined. NEW SYNONYMY.

Rhopalothrix (Octostruma) barberi Mann, 1922: 42, worker. Type locality: Trece Aguas, Alta Vera Paz, Guatemala. Holotype in National Museum of Natural History. examined. NEW SYNONYMY.

Rhopalothrix (Octostruma) equilatera Weber, 1934: 52, fig. 10, worker. Type locality: Tuli Creek, near San Miguel, Nicaragua. Syntypes in MCZC and NAW, examined. NEW SYNONYMY.

Etymology

Named for Luigi Balzan.

References

References based on Global Ant Biodiversity Informatics

  • Achury R., P. Chacon de Ulloa, and A. M. Arcila. 2008. Ant composition and competitive interactions with Wasmannia auropunctata in Tropical Dry Forest fragments. Revista Colombiana de Entomología 34 (2): 209-216.
  • Achury R., and A.V. Suarez. 2017. Richness and composition of ground-dwelling ants in tropical rainforest and surrounding landscapes in the Colombian Inter-Andean valley. Neotropical Entomology https://doi.org/10.1007/s13744-017-0565-4
  • Ahuatzin D. A., E. J. Corro, A. Aguirre Jaimes, J. E. Valenzuela Gonzalez, R. Machado Feitosa, M. Cezar Ribeiro, J. Carlos Lopez Acosta, R. Coates, W. Dattilo. 2019. Forest cover drives leaf litter ant diversity in primary rainforest remnants within human-modified tropical landscapes. Biodiversity and Conservation 28(5): 1091-1107.
  • Bolton B., J. Sosa-Calvo, F. Fernández, and J. E. Lattke. 2008. New synonyms in Neotropical myrmicine ants. Zootaxa 1732: 61-64.
  • Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
  • Branstetter M. G. and L. Sáenz. 2012. Las hormigas (Hymenoptera: Formicidae) de Guatemala. Pp. 221-268 in: Cano E. B. and J. C. Schuster. (eds.) 2012. Biodiversidad de Guatemala. Volumen 2. Guatemala: Universidad del Valle de Guatemala, iv + 328 pp
  • Brown W. L., Jr., and W. W. Kempf. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250.
  • Castano-Meneses G., R. De Jesus Santos, J. R. Mala Dos Santos, J. H. C. Delabie, L. L. Lopes, and C. F. Mariano. 2019. Invertebrates associated to Ponerine ants nests in two cocoa farming systems in the southeast of the state of Bahia, Brazil. Tropical Ecology 60: 52–61.
  • Castano-Meneses, G., M. Vasquez-Bolanos, J. L. Navarrete-Heredia, G. A. Quiroz-Rocha, and I. Alcala-Martinez. 2015. Avances de Formicidae de Mexico. Universidad Nacional Autonoma de Mexico.
  • Cuezzo F. 1999. Nuevas citas de hormigas de las tribus Dacetini y Basicerotini (Hymenoptera: Formicidae) para la República Argentina. Rev. Soc. Entomol. Argent. 58(3/4): 209-210.
  • Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
  • Del Toro, I., M. Vázquez, W.P. Mackay, P. Rojas and R. Zapata-Mata. Hormigas (Hymenoptera: Formicidae) de Tabasco: explorando la diversidad de la mirmecofauna en las selvas tropicales de baja altitud. Dugesiana 16(1):1-14.
  • Dias N. S., R. Zanetti, M. S. Santos, J. Louzada, and J. H. C. Delabie. 2008. Interaction between forest fragments and adjacent coffee and pasture agroecosystems: responses of the ant communities (Hymenoptera, Formicidae). Iheringia, Sér. Zool., Porto Alegre, 98(1): 136-142.
  • Emery C. 1894. Studi sulle formiche della fauna neotropica. VI-XVI. Bullettino della Società Entomologica Italiana 26: 137-241.
  • Fernandes I., and J. de Souza. 2018. Dataset of long-term monitoring of ground-dwelling ants (Hymenoptera: Formicidae) in the influence areas of a hydroelectric power plant on the Madeira River in the Amazon Basin. Biodiversity Data Journal 6: e24375.
  • Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
  • Fernández F., E. E. Palacio, W. P. Mackay, and E. S. MacKay. 1996. Introducción al estudio de las hormigas (Hymenoptera: Formicidae) de Colombia. Pp. 349-412 in: Andrade M. G., G. Amat García, and F. Fernández. (eds.) 1996. Insectos de Colombia. Estudios escogidos. Bogotá: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 541 pp
  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • Fichaux M., B. Bechade, J. Donald, A. Weyna, J. H. C. Delabie, J. Murienne, C. Baraloto, and J. Orivel. 2019. Habitats shape taxonomic and functional composition of Neotropical ant assemblages. Oecologia 189(2): 501-513.
  • 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.
  • Gonzales-Valvidia N. A., G. Gonzales-Escolastico, E. Barba, S. Hernandez-Daumas, and S. Ochoa-Gaona. 2013. Mirmecofauna associated with agroforestry systems in the Mesoamerican Biological Corridor in Tabasco, Mexico. Revista Mexicana de Biodiversidad 84: 306-317.
  • Groc S., J. H. C. Delabie, F. Fernandez, F. Petitclerc, B. Corbara, M. Leponce, R. Cereghino, and A. Dejean. 2017. Litter-dwelling ants as bioindicators to gauge the sustainability of small arboreal monocultures embedded in the Amazonian rainforest. Ecological Indicators 82: 43-49.
  • Groc S., J. Orivel, A. Dejean, J. Martin, M. Etienne, B. Corbara, and J. H. C. Delabie. 2009. Baseline study of the leaf-litter ant fauna in a French Guianese forest. Insect Conservation and Diversity 2: 183-193.
  • Kaspari M., D. Donoso, J. A. Lucas, T. Zumbusch, and A. D. Kay. 2012. Using nutritional ecology to predict community structure: a field test in Neotropical ants. Ecosphere 3(11): art.93.
  • 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. 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).
  • Kusnezov N. 1953. La fauna mirmecológica de Bolivia. Folia Universitaria. Cochabamba 6: 211-229.
  • Lapolla, J.S., T. Suman, J. Soso-Calvo and T.R. Schultz. 2006. Leaf litter ant diversity in Guyana. Biodiversity and Conservation 16:491–510
  • Longino J. T. 2013. A revision of the ant genus Octostruma Forel 1912 (Hymenoptera, Formicidae). Zootaxa 3699(1): 1-61.
  • Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
  • Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
  • Maes, J.-M. and W.P. MacKay. 1993. Catalogo de las hormigas (Hymenoptera: Formicidae) de Nicaragua. Revista Nicaraguense de Entomologia 23.
  • Mirmecofauna de la reserva ecologica de San Felipe Bacalar
  • Perrault G. H. 1988. Octostrumma [sic] betschi, n. sp. de Guyane Française (Hymenoptera, Formicidae). Revue Française d'Entomologie (Nouvelle Série) 10: 303-307.
  • Pires de Prado L., R. M. Feitosa, S. Pinzon Triana, J. A. Munoz Gutierrez, G. X. Rousseau, R. Alves Silva, G. M. Siqueira, C. L. Caldas dos Santos, F. Veras Silva, T. Sanches Ranzani da Silva, A. Casadei-Ferreira, R. Rosa da Silva, and J. Andrade-Silva. 2019. An overview of the ant fauna (Hymenoptera: Formicidae) of the state of Maranhao, Brazil. Pap. Avulsos Zool. 59: e20195938.
  • Santos Lopes J. F., N. Martins dos Reis Hallack, T. Archanjo de Sales, M. Silva Brugger, L. F. Ribeiro, I. N. Hastenreiter, and R. da Silva Camargo. 2012. Comparison of the Ant Assemblages in Three Phytophysionomies: Rocky Field, Secondary Forest, and Riparian Forest—A Case Study in the State Park of Ibitipoca, Brazil. Psyche doi:10.1155/2012/928371
  • Santos M. S., J. N. C. Louzada, N. Dias, R. Zanetti, J. H. C. Delabie, and I. C. Nascimento. 2006. Litter ants richness (Hymenoptera, Formicidae) in remnants of a semi-deciduous forest in the Atlantic rain forest, Alto do Rio Grande region, Minas Gerais, Brazil. Iheringia, Sér. Zool., Porto Alegre, 96(1): 95-101.
  • Silvestre R., M. F. Demetrio, and J. H. C. Delabie. 2012. Community Structure of Leaf-Litter Ants in a Neotropical Dry Forest: A Biogeographic Approach to Explain Betadiversity. Psyche doi:10.1155/2012/306925
  • Smith M. A., W. Hallwachs, D. H. Janzen. 2014. Diversity and phylogenetic community structure of ants along a Costa Rican elevational gradient. Ecography 37(8): 720-731.
  • Vasconcelos, H.L., J.M.S. Vilhena, W.E. Magnusson and A.L.K.M. Albernaz. 2006. Long-term effects of forest fragmentation on Amazonian ant communities. Journal of Biogeography 33:1348-1356
  • Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
  • Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.
  • da Silva, R.R., C.R.F. Brandao, and R. Silvestre. 2004. Similarity Between Cerrado Localities in Central and Southeastern Brazil Based on the Dry Season Bait Visitors Ant Fauna. Studies on Neotropical Fauna and Environment 39(3):191-199.