The paper about retaliation against cheating ants by their host-plant has just been included in a paginated issue of Evolutionary Biology. Here is the complete reference:

Malé P-JG, Ferdy J-B, Leroy C, Roux O, Lauth J, Avilez A, Dejean A, Quilichini A, & Orivel J (2014) Retaliation in response to castration promotes a low level of virulence in an ant-plant mutualism. Evolutionary Biology, 41(1):22-28. DOI: 10.1007/s11692-013-9242-7

It can be found here.