Individual and social immunity at work: multilevel defense mechanisms in Myrmica ants against an ectoparasitic fungus


Pathogens, parasites and their hosts provide excellent models for studies on coevolution. They are intrinsically linked but their evolutionary interests are different. However, not just unitary organisms can have parasites, and thus exhibit behavioral modifications due to parasitic effects, but social entities can also be targeted. Ants are frequently exploited by parasites, and in some cases parasitic organisms induce changes in the life history, physiology and behavior of the
ant hosts. To defend themselves, ants have evolved a variety of adaptations against parasites, including behavioral, biochemical and immunological responses to reduce virulence and transmission of entomopathogen agents. In addition to individual strategies, social organisms have an additional option to defend themselves against pathogens and parasites, and to fight infections. This line of defense in insect societies is known as the “social immune system”. Thus, social immunity is manifested at the level of the society.

In the frame of the current project Enikő Csata, PhD intends to study the individual and social defense strategies that help control the infection. I will investigate the defense mechanisms of individuals, and finally those phenomena that manifest at
the level of the society. More precisely the effect of fungus on the immune response of host’ ants, the costs (reduction in survival) linked to potential benefits (facilitated immune responses) of this association, the colonial defense mechanisms that could hinder the transmission of the parasite, and how the interaction network within a colony changes on the verge of a parasitic outbreak. The study of ant-fungi interactions enables us to clarify how parasites, pathogens, through affecting individuals, could ultimately influence the social system.