Ant–fungus mutualism - Wikipedia
Symbiotic adaptations in the fungal cultivar of leaf-cutting ants. Henrik H. Fungus-growing attine ants cultivate basidiomycete fungi for food. The leaf cutter ant, also know as the parasol ant, is one of a munber of social insects. Mutualism is a type of symbiotic relationship in which both partners benefit from The harvested fungus is then used as a food source for the ant colony. Leafcutter ant, (tribe Attini), any of 39 ant species abundant in the American relationship of leafcutter ants (sometimes called parasol ants) with fungi in the.
Leaf Cutter Ants
The fungus Escovopsis is a parasite in ant colonies, and the bacterium Pseudonocardia has a mutualistic relationship with ants. Pseudonocardia resides on the ants' integuments and assists in defending the ants from Escovopsis through the production of secondary metabolites. The yeast has a negative effect on the bacteria that normally produce antibiotics to kill the parasitic fungus and so may affect the ants' health by allowing the parasite to spread.
As she leaves, she takes with her a cluster of mycelium the vegetative portion of the fungus and actually begins a new fungal garden at her resting point using this mycelium. This grows to become the new fungal farm complete with the genes of the original cultivar preserved for another generation of ants. The relationship between attine ants and the Lepiotaceae fungus is so specialized that in many cases the Lepiotaceae is not even found outside of ant colony nests.
It is clear that evolutionary pressure has been exerted on these ants to develop such an organized system in which to feed the fungus and continue its reproduction. Studies done with the concept of the prisoner's dilemma in mind to test what further drives partner fidelity among species have shown that external factors are an even greater driving force. These gardens contain both the fungus itself and a low diversity community of bacteria.
Through enzymatic, metagenomic and metaproteomic analyses, the microbial communities in the fungus gardens of leaf-cutter ants Atta sexdens and Atta cephalotes have been explored. Many fungal amylases Silva et al. The bacterial community in the fungus gardens was identified using isolation, metagenomics and 16S sequencing Suen et al.
While the bacterial community has the genetic capacity for biomass degradation Suen et al. In this study, we explore microbial mediation in a generalist herbivore by combining feeding experiments with metaproteomic analyses. Specifically, we fed sub-colonies of leaf-cutter ants leaves, flowers, oats or a mixture of all three. Using a novel multidimensional platform, coupling liquid chromatography, ion mobility spectrometry and mass spectrometry LC-IMS-MSwe determined the metaproteomic response of fungus gardens on the different diets.
Our working hypothesis is that the fungal cultivar L. Methods Experimental design Atta cephalotes fungus gardens were excised from colonies excavated in the secondary tropical moist forest surrounding the Smithsonian Tropical Research Institute STRI Gamboa research station in Panama between Dec.
Five mature colonies were excavated. Since lab-reared sub-colonies without queens are unstable, five fungus chambers were excised from each colony to ensure that we would have sufficient numbers of replicates for proteomics.Leafcutter Ants - National Geographic
Care was taken to minimize disturbance to the fungus gardens and to ensure that a relatively even number of workers were distributed to each sub-colony.
Each sub-colony was randomly assigned to one of four feeding treatments, and received different plant biomass to use as substrate for cultivating their fungal mutualist.
The four feeding treatments were Lagerstroemia speciosa L. The distribution of these cavities varies with gender and species. Interestingly, no biological control method has yet been developed for the management of leaf-cutting ants. Entomopathogenic fungi infect insects by penetrating the integument.
Following this line of reasoning, the application of antibiotics may be an effective strategy against bacteria present on the exoskeleton of the ants, facilitating subsequent infection by entomopathogenic fungi and, thus increasing the potential of these agents for use in biological control of ants. Behavioral Defenses Against Ant Pathogens The social organization of ants is considered an effective defense strategy against invaders of their colonies, as these insects are considered to be a super-organism, where their behavioral cooperation through the division of tasks between castes complicates the spread of diseases within the colony.
Thus higher populations favored greater survival rates when challenged by pathogens. This would appear to be paradoxical. However when taking into consideration the defense mechanisms: Thus the colony should be considered as super-organism, with greater numbers of ants living in a cooperative regime leading to higher levels of disease resistance.
Currie and Stuart 22 observed the grooming behavior of workers of Atta colombica when exposed to pathogen contamination Trichoderma viride and Escovopsis of their nests. Two types of worker activities were observed: Furthermore, individual hygienic procedures such as self-grooming were observed. These prophylactic procedures occurred shortly after the introduction of pathogens, indicating that they were the primary defenses within an infected colony.
Grooming self- and fungus-grooming basically involves licking the surfaces to be cleaned and the storage of contaminated particles in the infrabucal cavity.