Subfamily MYRMICINAE
Tribe ATTINI

Cyphomyrmex rimosus (Spinola)

Cyphomyrmex rimosus, frontal view of the head of a worker (click image to enlarge).
Cyphomyrmex rimosus, side view of a worker (click image to enlarge).
Cyphomyrmex rimosus, side view of a queen (click image to enlarge).

Introduction
Cyphomyrmex is in the Attini tribe and is related to Atta and Trachymyrmex, which are also found in the southern United States.

Identification
Relatively small (head width greater than 0.62 mm) monomorphic ants that vary in color from dull light brown to blackish brown. The frontal lobes are conspicuous and expanded laterally and cover the antennal bases as well as much of the front of the head (see photo above, frontal view). The eyes are well developed. Mandibles with five teeth. Antennae11- segmented, lacking an apical club. Body is strongly sculptured with rounded tubercles present on the dorsum of the alitrunk (see photo of side view of worker above). Numerous appressed, scale-like hairs present on the body and appendages. This species is similar to C. minutus, which is apparently native to Florida and smaller in size. According to Snelling and Longino (1992), the head width of C. minutus is less than 0.56 mm and hairs in center of first gastral tergite are closely appressed and usually separated by more than their own lengths, whereas in C. rimosus, the head width is greater than 0.62 mm and hairs on first gastral tergite are not completely appressed and separated by less than their own lengths (Snelling and Longino 1992). I examined specimens of both species at the collection in Gainesville, FL and had a hard time telling them apart, but I did not have an ocular micrometer to measure head widths.

Common Names
Fungus growing ant

Biology and Economic Importance
Similar to other Attines, Cyphomyrmex, grows subterranean fungus gardens, which are grown on a substrate of vegetable matter and dead insects. This species is very common in open habitats such as pastures and also in open woodlands such as longleaf pine forests. We have found colonies in the soil under rocks, logs, cow manure, or other objects.

Distribution
This exotic species is native to the Neotropics ocurring from Mexico south to Argentina, and also the West Indies. In the US its range is given as FL AL, MS, LA, TX, AZ, and CA (Smith 1979), and we have also collected it in GA. It likely occurs along the coastal plain in SC and NC as well.

Literature Cited
Smith, D. R. 1979. In Catalog of Hymenoptera in America north of Mexico. Smithsonian Institution Press, Washington D. C. Vol. 2, pp. 1323-1427.

Snelling, R. R. and J. T. Longino. 1992. Revisionary notes on the fungus-growing ants of the genus Cyphomyrmex, rimosus-group (Hymenoptera: Formicidae: Attini). Pages 479-494 in Quintero, D. and A. Aiello. Insects of Panama and Mesoamerica: selected studies. Oxford University Press, Oxford. 692 pp.

Links
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