Fungi specialised to attack insects (in the photo from the blog
Hyphal Happenings) are commonly present in the environment so
that they have driven many aspects of the insect evolution,
affecting behavioural, chemical and immune systems. In a recent
paper published in PLoS One, Christine Turnbull and colleagues
compared the activity of cuticular antifungal compounds in
thrips species (Insecta: Thysanoptera) representing a gradient
of increasing group size and sociality: solitary, communal,
social and eusocial, against the entomopathogen Cordyceps
bassiana. Solitary and communal species showed little or no
activity. In contrast, the social and eusocial species killed
this fungus, suggesting that the evolution of sociality has been
accompanied by sharp increases in the effectiveness of
antifungal compounds. This paper suggests a new insight into the
evolution of thrips sociality since traits enabling nascent
colonies to defend themselves against microbial pathogens should
be considered essential for social evol