Data from: Dynamic disease management in Trachymyrmex fungus-growing ants (Attini: Formicidae)

Multipartner mutualisms have potentially complex dynamics, with
compensatory responses when one partner is lost or relegated to a minor
role. Fungus-growing ants (Attini) are mutualistic associates of
basidiomycete fungi and antibiotic-producing actinomycete bacteria; the
former are attacked by specialized fungi (Escovopsis) and diverse
generalist microbes. Ants deploy biochemical defenses from bacteria and
metapleural glands (MGs) and express different behaviors to control
contaminants. We studied four Trachymyrmex species that differed in
relative abundance of actinomycetes to understand interactions among
antimicrobial tactics that are contingent on the nature of infection. MG
grooming rate and actinomycete abundance were negatively correlated. The
two species with high MG grooming rates or abundant actinomycetes made
relatively little use of behavioral defenses. Conversely, the two species
with relatively modest biochemical defenses relied heavily on behavior.
Trade-offs suggest that related species can evolutionarily diverge to rely
on different defense mechanisms against the same threat. Neither bacterial
symbionts nor MG secretions thus appear to be essential for mounting
defenses against the specialized pathogen Escovopsis, but reduced
investment in one of these defense modes tends to increase investment in
the other.