Cyphomyrmex

A genus of fungus growing ants.

Identification
Schultz et al (2002), Mackay and Serna (2010) - Cyphomyrmex workers and females are easily recognized, as the frontal carinae form a shield on the dorsum of the head, which covers most of the head. The mesosoma has a series of pairs of blunt tubercles in nearly all species. The first opisthogastral tergum lacks tubercles. Most surfaces are dull and without sculpture; the hairs are mostly limited to appressed, often scale-like setae that are nearly always restricted to the gaster and the head.

The genus is divided into two species complexes, the strigatus complex (Kempf 1964) and the rimosus complex (Kempf 1965; Snelling and Longino 1992). Workers of the strigatus complex can be recognized by the closed antennal scrobe (sometimes with poorly defined margins), mandibles with six or more teeth, and with a single medial pronotal tubercle (apparently a fusion of two tubercles). The species group is confined to South America. The workers of the rimosus complex have an open antennal scrobe (anteriorly), with the preocular carina curved mesially in front of the eye, and not directed to the posterior corner of the head, the mandibles have five teeth, and the pronotum lacks medial tubercles, or has a pair of tubercles. Species in the rimosus group range from the United States to South American.

Cyphomyrmex longiscapus, Cyphomyrmex costatus and Cyphomyrmex wheeleri are considered to be part of the rimosus group but share some morphological features with the strigatus complex.

Distribution
Mackay and Serna (2010) - Cyphomyrmex has two centers of species richness: the rimosus group at about 10° north (Mayhe-Nunes and Jaffe 1998), whereas the majority of the species of the strigatus group is restricted to 20° and 30° south (Sanhudo et al. 2007). The strigatus group lacks species with wide distributions (Mayhe-Nunes and Jaffe 1998) as is found in the rimosus complex.

Biology
Schultz et al (2002), Mackay and Serna (2010) - Most species nest in the soil, in rotten logs and stumps, or in hollow dead twigs. This genus also nests under bark, under moss, and within epiphytic pseudobulbs (Snelling and Longino 1992). Colonies are small, probably not exceeding 500 workers (Snelling and Longino 1992). All Cyphomyrmex species cultivate badisiomycete fungi in the tribe Leucocoprineae. In the rimosus group, most species grow fungi in a yeast form (small masses of unicellular fungal cells) rather than in the multicellular mycelial form typical for all other attine ant gardens (Schultz et a1. 2002; Schultz and Brady 2008). Cyphomyrmex longiscapus, Cyphomyrmex costatus and Cyphomyrmex wheeleri are considered to be part of the rimosus group but share some morphological features with the strigatus complex. They are also the only species in the rimosus group that are known to cultivate mycelium gardens, whereas, so far as is known, all other rimosus group species cultivate yeast gardens.

Nomenclature

 *  CYPHOMYRMEX [Myrmicinae: Attini]
 * Cyphomyrmex Mayr, 1862: 690. Type-species: Cyphomyrmex minutus, by monotypy.
 * [Type-species not Cryptocerus rimosus, unjustified subsequent designation by Wheeler, W.M. 1911f: 161. Type-species not Meranoplus difformis, unjustified subsequent designation by Emery, 1924d: 340.]
 * Cyphomyrmex junior synonym of Cataulacus: Roger, 1863b: 39.
 * Cyphomyrmex revived from synonymy: Mayr, 1863: 406.
 * Cyphomyrmex subgenus of Atta: Forel, 1912e: 188.
 * Cyphomyrmex revived status as genus: Emery, 1913b: 251.
 * Cyphomyrmex senior synonym of Cyphomannia: Kempf, 1962b: 29; Kempf, 1972a: 92.