Drosophila melanogaster infected with Wolbachia strain wMelCS prefer cooler temperatures: Wolbachia alters temperature preference

1. Temperature plays a fundamental role in host-pathogen interactions. 2. Wolbachia is an endosymbiotic bacteria that infects about 40% of arthropod species, which can affect host behaviour and reproduction. Yet, the effect of Wolbachia on host thermoregulatory behaviour is largely unknown, despite its use in disease vector control programs in thermally variable environments. 3. Here, we used a thermal gradient to test whether Drosophila melanogaster infected with Wolbachia strain w MelCS exhibit different temperature preferences ( T p ) to uninfected flies. 4. We found that Wolbachia -infected flies preferred a cooler mean temperature ( T p = 25.06±0.25°C) than uninfected flies ( T p = 25.78±0.24°C). 5. This finding suggests that Wolbachia -infected hosts might seek out cooler microclimates to reduce exposure to and lessen the consequences of high temperatures. This finding has generated hypotheses that will be fruitful in areas of research for exploring the mechanisms by which the change in T p occurs in this complex and significant host-pathogen-environment interaction.