Mariana O Barcoto1, Felipe Pedrosa2, Odair C Bueno3, Andre Rodrigues1,3. 1. Department of Biochemistry and Microbiology, UNESP - São Paulo State University, Rio Claro, São Paulo, Brazil. 2. Department of Ecology, UNESP - São Paulo State University, Rio Claro, São Paulo, Brazil. 3. Centre for the Study of Social Insects, UNESP - São Paulo State University, Rio Claro, São Paulo, Brazil.
Abstract
BACKGROUND: Leaf-cutter ants are considered to be a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism responsible for a characteristic disease in fungus gardens. We also characterise the damage caused by this fungus by evaluating physiological and behavioural responses of Atta sexdens rubropilosa subcolonies infected with Syncephalastrum sp. RESULTS: Syncephalastrum sp. fulfils Koch's postulates characterising it as a pathogenic microorganism. Ant workers recognise the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, subcolony deterioration and an increase in the amount of waste generated, all resulting in subcolony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g. worker mortality caused by an entomopathogenic fungus). CONCLUSION: Syncephalastrum sp. treatment resulted in progressive damage in subcolonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf-cutter ants.
BACKGROUND: Leaf-cutter ants are considered to be a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism responsible for a characteristic disease in fungus gardens. We also characterise the damage caused by this fungus by evaluating physiological and behavioural responses of Atta sexdens rubropilosa subcolonies infected with Syncephalastrum sp. RESULTS:Syncephalastrum sp. fulfils Koch's postulates characterising it as a pathogenic microorganism. Ant workers recognise the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, subcolony deterioration and an increase in the amount of waste generated, all resulting in subcolony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g. worker mortality caused by an entomopathogenic fungus). CONCLUSION:Syncephalastrum sp. treatment resulted in progressive damage in subcolonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf-cutter ants.
Authors: Kerstin Voigt; Timothy Y James; Paul M Kirk; André L C M de A Santiago; Bruce Waldman; Gareth W Griffith; Minjie Fu; Renate Radek; Jürgen F H Strassert; Christian Wurzbacher; Gustavo Henrique Jerônimo; David R Simmons; Kensuke Seto; Eleni Gentekaki; Vedprakash G Hurdeal; Kevin D Hyde; Thuong T T Nguyen; Hyang Burm Lee Journal: Fungal Divers Date: 2021-09-29 Impact factor: 24.902
Authors: Sean Araújo; Janaína Seibert; Ana Ruani; Ricardo Alcántara-de la Cruz; Artur Cruz; Alana Pereira; Doraí Zandonai; Moacir Forim; Maria Fátima Silva; Odair Bueno; João Fernandes Journal: Insects Date: 2022-04-06 Impact factor: 3.139