Effect of entomopathogenic fungus Beauveria bassiana on behavior of termite Reticulitermes chinensis

Termites play a dual ecological role as vital decomposers and significant pests that cause economic damage globally. In China, Reticulitermes chinensis is a prevalent subterranean termite species managed primarily through chemical termiticides, which pose environmental and health risks. Entomopathogenic fungi (EPF), particularly Beauveria bassiana, offer a promising alternative due to their eco-friendly targeted approach to pest control. This study investigated the effects of B. bassiana on various behaviors (allogrooming, trophallaxis, vibration, cannibalism, burial, locomotion, and foraging) and the survival of R. chinensis. Termites exposed to higher fungal concentrations (10⁸ conidia/ml) showed significantly increased allogrooming and vibration behaviors, while trophallaxis remained unaffected. Burial behavior was significantly more pronounced in response to fungus-killed termites compared to controls (cadavers killed by freezing), though cannibalism showed no significant difference between the two dead cadaver types. Locomotion analysis revealed that exposure to B. bassiana reduced distance moved and velocity, while increasing turn angle and angular velocity, as measured at 24 and 48 h after fungal exposure. Foraging activity after infection was notably disrupted, with reduced time spent and fewer visits to food zones. Mortality was dose-dependent in individually caged termites, but no significant survival differences were observed when termites were caged with nestmates, suggesting potential social buffering effects. These findings demonstrate that B. bassiana not only impacts termite survival but also alters behaviors, highlighting its potential as a biological control agent. However, termite behavioral defenses may mitigate fungal spread, necessitating further investigation into optimizing fungal pathogenicity within social insect colonies.