Testing the beneficial acclimation hypothesis: temperature effects on mating success in a butterfly

Traditionally, it has been assumed that all acclimation changesto the phenotype enhance the performance of an individual organismin the environment in which those changes were induced (beneficialacclimation hypothesis [BAH]), a theory that has been repeatedlychallenged in recent years. We here use a full-factorial designwith 2 developmental and 2 acclimation temperatures to testtheir effects on reproductive performance in the tropical butterfly,Bicyclus anynana. Competition experiments among virgin malesfrom different thermal groups revealed that, at 20 °C, bothgroups acclimated to 20 °C achieved more than twice as manymatings as those acclimated to 27 °C, whereas at 27 °C,only one group (acclimated to 27 °C) outperformed all others.Chill-coma recovery times were also longer for butterflies thatdeveloped at higher temperatures, indicating that butterfliesresponded physiologically to the temperatures at which theywere reared. Our results support the BAH at least in part, anddo not support any alternative hypotheses.