Foraging Macrotermes natalensis fungus-growing termites avoid a mycopathogen but not an entomopathogen

Fungus-growing termites have to defend both themselves and their monoculture fungal cultivars from antagonistic microbes. One of the ways that pathogens can enter the termite colony is on the plant substrate that is collected by termite foragers. In order to understand whether foragers avoid substrate infected with antagonists, we offered sub-colonies of Macrotermes natalensis a choice between food exposed to either a mycopathogenic or an entomopathogenic fungus, and control food. Workers did not show any preference between entomopathogen-exposed and control substrate, but significantly avoided the mycopathogen-exposed substrate. This suggests that the behaviour of foraging workers is more strongly influenced by pathogens affecting their crop than those posing risks to the termite workers themselves.