Novel applications of thermocyclers for phenotyping invertebrate thermal responses

Summary High‐throughput genomic methods are increasingly used to investigate invertebrate thermal responses with greater dimensionality and resolution than previously achieved. However, corresponding methods for characterizing invertebrate phenotypes are still lacking. To scale up the characterization of invertebrate thermal responses, we propose a novel use of thermocyclers as temperature‐controlled incubators. Here, we tested the performance of thermocyclers as incubators and demonstrated the application of this method to efficiently characterize the thermal responses of model and non‐model invertebrates. We found the thermocyclers performed with high precision, accuracy and resolution under various and fluctuating ambient conditions. We were able to successfully characterize the temperature‐dependent development of grasshopper eggs (Warramaba virgo), as well as the effects of fluctuating temperature cycles on the survival of mosquito eggs (Aedes aegypti) and developmental success of Drosophila simulans larvae, all with similar survival rates to conventional methods. Thermocyclers are a general and transferrable means to scale up current methods of incubating small invertebrates. They permit rapid characterization of high‐dimensional physiological responses to natural thermal regimes. When combined with existing approaches in thermal and evolutionary biology, these methods will advance our understanding of, and ability to predict, biological adaptations and responses to environmental changes.