Nesting biology and fungiculture of the fungus-growing ant, Mycetagroicus cerradensis: New light on the origin of higher attine agriculture

Scott E. Solomon1, 6a*, Cauê T. Lopes2b, Ulrich G. Mueller3c, Andre Rodrigues4d, Jeffrey Sosa-Calvo1, 5e, Ted R. Schultz1f, Heraldo L. Vasconcelos2g

1Department of Entomology, National Museum of Natural History, Smithsonian Institution, POB 37012, Washington, DC 20013-7012, U.S.A.
2Institute of Biology, Federal University of Uberlândia (UFU), C.P. 593, Uberlândia, MG, 38400-902, Brazil
3Section of Integrative Biology, The University of Texas at Austin, 1 University Station C0930, Austin, TX, 78712, U.S.A.
4Center for the Study of Social Insects (CEIS), State University of São Paulo, Av. 24-A 1515, Rio Claro, SP, 13506- 900, Brazil
5Maryland Center for Systematic Entomology, Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD, 20742, U.S.A
6Current address: Department of Ecology and Evolutionary Biology, Rice University, 6100 Main Street, MS 170, Houston, TX 77005, U.S.A.

Abstract

The genus Mycetagroicus is perhaps the least known of all fungus-growing ant genera, having been first described in 2001 from museum specimens. A recent molecular phylogenetic analysis of the fungus-growing ants demonstrated that Mycetagroicus is the sister to all higher attine ants (Trachymyrmex, Sericomyrmex, Acromyrmex, Pseudoatta, and Atta), making it of extreme importance for understanding the transition between lower and higher attine agriculture. Four nests of Mycetagroicus cerradensis near Uberlândia, Minas Gerais, Brazil were excavated, and fungus chambers for one were located at a depth of 3.5 meters. Based on its lack of gongylidia (hyphal-tip swellings typical of higher attine cultivars), and a phylogenetic analysis of the ITS rDNA gene region, M. cerradensis cultivates a lower attine fungus in Clade 2 of lower attine (G3) fungi. This finding refines a previous estimate for the origin of higher attine agriculture, an event that can now be dated at approximately 21-25 mya in the ancestor of extant species of Trachymyrmex and Sericomyrmex.

Keywords: Attini, Cerrado, evolutionary transitions, Leucocoprinus, molecular systematics, nest architecture

Correspondence: a*ses4@rice.edu, bcauelopes@gmail.com, cumueller@mail.utexas.edu, dandrer@rc.unesp.br, esossajef@si.edu, fschultzt@si.edu, gheraldo@umuarama.ufu.br, *Corresponding author

Editor: Robert Jeanne was editor of this paper.

Received: 6 May 2009 | Accepted: 20 January 2010 | Published: 4 February 2011

ISSN: 1536-2442 | Volume 11, Number 12

Solomon SE, Lopes CT, Mueller UG, Rodrigues A, Sosa-Calvo J, Schultz TR, Vasconcelos HL. 2011. Nesting biology and fungiculture of the fungus-growing ant Mycetagroicus cerradensis: New light on the origin of higher-attine agriculture. Journal of Insect Science 11:12 available online: insectscience.org/11.12


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