Density of Cardinium infection in adult a) male E. suzannae and b) female E. suzannae.

Densities were measured by estimating the amount of single copy Cardinium gyrB genes relative to single copy host ef1-alpa genes with qPCR. N = 5–10 for males (denoted by numbers above whisker plots) and N = 5 for females. Each sample was run with three technical replicates. Color of bars denotes temperature range (grey = 27°C, red = 32–29°C, blue = 20–17°C). Treatments are also separated by the stage at which temperature exposure began. Asterisks denote significant differences compared to the symbiont density at 27°C.