Plasticity of grooming behavior against entomopathogenic fungus Metarhizium anisopliae in the ant Lasius japonicus

• Published in: Journal of ethology Vol. 30; no. 1; pp. 23 - 27
• Main Authors: Okuno, Masaki, Tsuji, Kazuki, Sato, Hiroki, Fujisaki, Kenji
• Format: Journal Article
• Language: English
• Published: Japan Springer-Verlag 01.01.2012; Springer Japan; Springer
• Subjects: Animal and plant ecology; Animal Ecology; Animal ethology; Animal, plant and microbial ecology; Animals; Autoecology; Behavioral Sciences; Biological and medical sciences; Biomedical and Life Sciences; Colonies; Cuticles; Defense mechanisms; ectoparasites; entomopathogenic fungi; Evolutionary Biology; Formicidae; Fundamental and applied biological sciences. Psychology; fungal spores; Grooming; Group size; Infection; Lasius; Life Sciences; Metarhizium anisopliae; Parasites; Pathogens; Plasticity (behavioral); Protozoa. Invertebrata; Psychology. Psychoanalysis. Psychiatry; risk; Risk factors; social insects; Spores; Survival; survival rate; Zoology; Allogrooming; Group size; Self-grooming; Fungal dosage; Survivorship; Behavioral defence mechanism; Grooming behavior; Entomopathogen; Host parasite relation; Insecta; Defensive behavior; Formicoidea; Fungi; Metarhizium anisopliae; Plasticity; Fungi Imperfecti; Aculeata; Formicidae; Parasite; Social insect; Survival; Mycoparasite; Social interaction; Arthropoda; Hymenoptera; Invertebrata
• ISSN: 0289-0771; 1439-5444
• DOI: 10.1007/s10164-011-0285-x

Social insects employ many types of defense mechanisms against parasites and pathogens because they face high risks from infections due to crowded living conditions with closely related nestmates. Grooming behavior, including self-grooming and allogrooming, can remove fungal spores on the cuticles of social insects and may be a behavioral defense mechanism to improve survivorship. Allogrooming between nestmates has been predicted to be especially important as a defense against ectoparasites. However, little is known about the plasticity of grooming behavior in susceptible environments. Here, we show that the ant Lasius japonicus increases the frequency of allogrooming rather than self-grooming to improve survivorship against the entomopathogenic fungus Metarhizium anisopliae. We found that increasing fungal dosage and ant group size influenced the plasticity of grooming behavior. Additionally, the survival rate of the ants over 30 days improved with increased group size. Our results suggest that social insects opt for altruistic behavior to prevent the spread of diseases. This study illustrates how ants maintain colonies through grooming behavior in the presence of fungal spores.