Display omitted •Conservation BC programs require confirmation of predator sources.•We optimize a DNA mark-capture procedure to confirm the dispersal of predators.•Orius laevigatus was marked for 6 days in the laboratory and in semi-field conditions.•In the field, 32 predators were marked on sticky traps placed between crops.•Such DNA mark-recaptured procedure has the potential to tag insect source habitats. Implementation of landscape approaches to conservation biological control programs requires the confirmation of putative sources that contribute to predator colonization of crops. This study aims to confirm predator dispersal from an alfalfa field to a neighboring peach orchard with a DNA mark-capture procedure based on a topical application of a solution of grinded brine shrimp cysts, Artemia spp. (Anostraca: Artemiidae), followed by a conventional PCR. To optimize the marking procedure, a well-known predator present in orchards as well as in arable crops, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), was used as a model in this study. In greenhouse trials, the acquisition and the retention time of the Artemia markings were determined, either directly by spraying them with the Artemia solution or indirectly via residual contact on caged plants after the spray. The topical mark remained detectable on O. laevigatus after 6 days, and 50% of the tested predators were positive 3 days after walking on the sprayed plants. After that, a 25m2 strip of an alfalfa crop neighboring to a peach orchard was sprayed with the Artemia solution just after the alfalfa cuts, and several common predator species were collected using sticky traps placed between both crops. After PCR analysis with the Artemia specific primers, 32% of the analyzed predators (coccinellids, anthocorids, chrysopids, and mirids) showed the mark. The results of this study confirm the usefulness of this marking method to monitor dispersal of biological control agents between neighboring crops, in this case alfalfa and peach.