Drosophila melanogaster does not exhibit a behavioural fever response when infected with Drosophila C virus.

Behavioural fever is a widely conserved response to infection. The host increases body temperature (Tb) by altering their preferred temperature (Tp), generating a fever and delaying or avoiding pathogen-induced mortality. This response is not ubiquitous in insects, however, although few studies have investigated this response to viral infection. Here, we examined the change in Tp of Drosophila in response to virus infection using a thermal gradient. No difference in Tp was observed. We suggest that the lack of behavioural fever could be due to the increased energy cost of maintaining a higher Tb whilst the immune response is active. To the best of our knowledge, this is the first study to assay for changes in Tp of infected Drosophila.