Hypopi of Lardoglyphus zacheriOudemans, 1927 were found attached to larder beetles (Coleoptera: Dermestidae) colonising experimental pig carcasses in the Parque Natural Aiako Harria, Errenteria, Gipuzkoa, northern Spain. Five pig carcasses were used for a study of arthropod colonisation during the decomposition process, and the experiment lasted 88 days (from July to October 2010). Hypopi were found when the carcasses commenced reduction to dried remains, on day 29 (August 24), and were attached to Dermestes frischi Kugelann, 1792 and to D. undulatus Brahm, 1790, all collected on the same carcass (carcass 3, C3). No more lardoglyphid mites were detected from August 29 to the last day of sampling, October 22 2010. This is the first record of Lardoglyphus hypopi on D. undulatus and of L. zacheri from the Iberian Peninsula.