Body size, lifespan, behaviour and body temperature in relation to environmental variables in wild field crickets (Gryllus campestris) in a meadow in Northern Spain, May and June, 2017

Crickets in the body temperature dataset were collected in the wild in 2017 and then used to measure their body temperature changes with time under sun exposure. Crickets in the basic and behavioural traits datasets, were reared in captivity from parents collected at ten different populations, and then released in the study meadow after adult emergence. Data on body temperature increase were obtained from a sample of crickets collected in the wild and retained in a controlled area outside using a line attached to a copper ring glued to their thorax. Crickets were maintained in captivity and randomly selected every day to run the temperature increase trials. Trials were carried out in an area with mown grass. Before entering the trial, each individual was cooled to a temperature of 13ºC. During the cooling process, ambient temperature, humidity and reflected apparent temperature were measured using a thermal imagining camera (FLIR T4). Once the cricket reached the base temperature, it was released in the arena and its temperature measured at 1 minute intervals with the same camera, for a minimum of 20 minutes. Trial ended when the temperature plateaued and remained stable for approximately 2 minutes.