A method for rapidly mass laser-marking individually coded ground beetles (Coleoptera: Caribidae) in the field

1. A laser-marking technique is described that may be used to rapidly mass-mark and individually code insects in the field. In this study, ground beetles were marked but the method is applicable to a wide range of organisms with a hard exoskeleton or shell. 2. In a field-scale capture-recapture study conducted in winter wheat, 8266 beetles were coded. Individuals marked in the first week of the trial and recaptured 2 months later retained their codes, which were therefore considered permanent. 3. Assemblages were dominated numerically by Pterostichus cupreus, which formed more than 98% of the total captures. Of the 8046 released P. cupreus, 2269 were recaptured. As an illustration of the use of these data, the POPAN parameterisation of the Jolly-Seber model was used to estimate a whole-field population of 17 237 individuals, equating to a density of 0.46 beetles m(-2).