Cyphomyrmex bicornis

Cyphomyrmex bicornis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Cyphomyrmex
Species:	C. bicornis
Binomial name
	Cyphomyrmex bicornis; Forel, 1895 Specimen Labels

This species is known from two widely separated collection sites, one in southern Brazil, the other in Amazonian Colombia. The Colombian material was found in a 100mm deep soil sample in a primary forest (Castro et al., 2018).

Identification

See description section below.

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -22.35° to -22.35°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), Colombia.

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 Fungus Growing

For additional details see Fungus growing ants.

A handful of ant species (approx. 275 out of the known 15,000 species) have developed the ability to cultivate fungus within their nests. In most species the fungus is used as the sole food source for the larvae and is an important resource for the adults as well. Additionally, in a limited number of cases, the fungus is used to construct part of the nest structure but is not as a food source.

These fungus-feeding species are limited to North and South America, extending from the pine barrens of New Jersey, United States, in the north (Trachymyrmex septentrionalis) to the cold deserts in Argentina in the south (several species of Acromyrmex). Species that use fungi in nest construction are known from Europe and Africa (a few species in the genera Crematogaster, Lasius).

The details of fungal cultivation are rich and complex. First, a wide variety of materials are used as substrate for fungus cultivating. The so-called lower genera include species that prefer dead vegetation, seeds, flowers, fruits, insect corpses, and feces, which are collected in the vicinity of their nests. The higher genera include non leaf-cutting species that collect mostly fallen leaflets, fruit, and flowers, as well as the leafcutters that collect fresh leaves from shrubs and trees. Second, while the majority of fungi that are farmed by fungus-feeding ants belong to the family Lepiotaceae, mostly the genera Leucoagaricus and Leucocoprinus, other fungi are also involved. Some species utilise fungi in the family Tricholomataceae while a few others cultivate yeast. The fungi used by the higher genera no longer produce spores. Their fungi produce nutritious and swollen hyphal tips (gongylidia) that grow in bundles called staphylae, to specifically feed the ants. Finally, colony size varies tremendously among these ants. Lower taxa mostly live in inconspicuous nests with 100–1000 individuals and relatively small fungus gardens. Higher taxa, in contrast, live in colonies made of 5–10 million ants that live and work within hundreds of interconnected fungus-bearing chambers in huge subterranean nests. Some colonies are so large, they can be seen from satellite photos, measuring up to 600 m3.

Based on these habits, and taking phylogenetic information into consideration, these ants can be divided into six biologically distinct agricultural systems (with a list of genera involved in each category):

Nest Construction

A limited number of species that use fungi in the construction of their nests.

some Crematogaster
some Lasius

Lower Agriculture

Practiced by species in the majority of fungus-feeding genera, including those thought to retain more primitive features, which cultivate a wide range of fungal species in the tribe Leucocoprineae.

Coral Fungus Agriculture

Practiced by species in the Apterostigma pilosum species-group, which cultivate fungi within the Pterulaceae.

some Apterostigma

Yeast Agriculture

Practiced by species within the Cyphomyrmex rimosus species-group, which cultivate a distinct clade of leucocoprineaceous fungi derived from the lower attine fungi.

some Cyphomyrmex

Generalized Higher Agriculture

Practiced by species in several genera of non-leaf-cutting "higher attine" ants, which cultivate a distinct clade of leucocoprineaceous fungi separately derived from the lower attine fungi.

Leaf-Cutter Agriculture

A subdivision of higher attine agriculture practiced by species within several ecologically dominant genera, which cultivate a single highly derived species of higher attine fungus.

Note that the farming habits of Mycetagroicus (4 species) are unknown. Also, while species of Pseudoatta (2 species) are closely related to the fungus-feeding genus Acromyrmex, they are social parasites, living in the nests of their hosts and are not actively involved in fungus growing. ‎

Castes

The queen and male are unknown.

Nomenclature

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

bicornis. Cyphomyrmex bicornis Forel, 1895j: 179 (w.) BRAZIL (Rio se Janeiro).
- Type-material: syntype workers (number not stated).
- Type-locality: Brazil: Rio de Janeiro, Colonia Alpina, nr Theresopolis (E.A. Göldi).
- Type-depository: MHNG.
- Status as species: Emery, 1924d: 341; Borgmeier, 1927c: 125; Weber, 1940a: 409 (in key); Kempf, 1966: 177 (redescription); Weber, 1966: 167; Kempf, 1972a: 92; Snelling, R.R. & Longino, 1992: 481 (in key); Bolton, 1995b: 167.
- Distribution: Brazil.

Description

Kempf (1966) - This rare and cryptic species, which so far has been collected only twice, is apparently confined to the woodlands in the Mantiqueira Mountains in Rio de Janeiro State. The specimen described above agrees well with the description of the type. Only the epinotum and postpetiolar dorsum are even smoother than in the type, lacking the vestigial tumuli mentioned by Forel. According to the original description, the mandibles are 5-6 toothed. My specimen has the tips of the mandibles broken off, but it seems that the basic dental number is five, there being a minute intercalary tooth in the diastema between the 2nd and 3rd tooth.

The present species is quite distinct, chiefly in the peculiarly auriculate occipital lobes of head, which occur only in Cyphomyrmex laevigatus. The latter, however, differs conspicuously from bicornis, from which it is differentiated clearly here.

Worker

Kempf (1966) - Total length 3.2 mm; head length 0.83 mm; head width 0.76 mm; thorax length 1.04 mm; hind femur length 0.83 mm. Brown; head and gaster somewhat darker. Integument densely granular, opaque, including the antennal scrobe.

Head (fig 5). Clypeus: anterior border feebly convex with a faint mesial notch, flanked on each side by a small tooth next to origin of frontal lobes. A median tumulus behind frontal area, flanked by a broad circular depression in the frontal lobes, above the antennal sockets. Carinae on vertex short but strong, diverging cephalad. Eyes with about 8 facets across greatest diameter. Preocular carinae curving mesad in front of eyes. Postocular carinae forming the strongly lamellate border the huge, auriculate, occipital lobes, continuing foreward and obliquely downward beneath the eyes, fading out just in front of the anterior orbit of eyes. Lower border of sides of head strongly but irregularly carinate. Scape rather thin at base, gradually thickening in a club-like fashion toward apex; its upper and lower border of leading face finely carinulate. Funicular segments II-VIII scarcely longer than broad.

Thorax (fig 23). Pronotum without dorsal projections, dorso-laterally marginate by a blunt and feeble longitudinal welt; antero-inferior corner subdentate and rectangular. Mesonotum: a pair of anterior, conical, bluntly tipped spines; a posterior pair of more approximate longitudinal welts, which are obtusely carinate, anteriorly diverging and rounded in profile. Mesoepinotal constriction strong. Epinotum completely unarmed and convex in both directions. Legs somewhat compressed, femora ventrally with a lamellate carinule. Hind femora ventrally dilated at basal third into an obtuse triangular lobe (fig 41).

Pedicel as shown in Figs. 23 and 33. Petiolar node broader than long, its anterior corners rounded in dorsal view, its dorsum without ridges, its postero-superior border without a projecting laminule. Postpetiole still broader than petiole, strikingly transverse, lacking conspicuous dorsal and lateral impressions and tumuli. Anterior border of tergum I of gaster carinulate above the postpetiolar insertion; laterally immarginate.

Hairs decumbent or appressed on body and appendages, rather fine and not scale-like, somewhat glistening, more conspicuous on scapes and legs.

Kempf (1966) Figs. 14-26
Kempf (1966) Figs. 27-50

Type Material

Kempf (1966) - Worker(s) collected by E. A. Goeldi, presumably deposited in the Forel collection; not seen.

References

Castro, D., Fernández, F., Meneses, A., Tocora, M., Sanchez, S., Peña-Venegas, C. 2018. A preliminary checklist of soil ants (Hymenoptera: Formicidae) of Colombian Amazon. Biodiversity Data Journal 6: e29278 (DOI 10.3897/BDJ.6.e29278).
Forel, A. 1895c. Die Ameisen- und Termitengäste von Brasilien. Anhang. Beschreibung einiger neuer brasilianischer Ameisenarten. Verh. K-K. Zool.-Bot. Ges. Wien 45: 178-179 (page 179, worker described)
Kempf, W. W. 1966 [1965]. A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part II: Group of rimosus (Spinola) (Hym., Formicidae). Stud. Entomol. 8: 161-200 (page 177, see also)

References based on Global Ant Biodiversity Informatics

Lapola D. M., and H. G. Fowler. 2008. Questioning the implementation of habitat corridors: a case study in interior São Paulo using ants as bioindicators. Braz. J. Biol., 68(1): 11-20.