A sample of chigger mites from bat hosts collected in the Balearic Islands (Western Mediterranean Sea) is found to include two species. These are the first records of bat-infesting chiggers identified to species in Spain. Chiggers collected from Pipistrellus kuhlii (Kuhl) in Menorca are identified as Oudemansidium komareki (Daniel et Dusbábek, 1959); this species, which was known from Austria, Bulgaria, Romania, Slovakia, Moldova, Crimea, and Azerbaijan, is recorded for the first time in Spain. Chiggers collected from Plecotus austriacus (Fischer) in Formentera are identified as Trombicula knighti Radford, 1954, which was insufficiently described from a bat in Yemen and known only from its type locality. We transfer this species to the genus Trisetica Traub et Evans, 1950 and provide its re-description based on paratypes and the material from the Balearic Islands. The species Sasatrombicula (Rudnicula) balcanica Kolebinova, 1966 is synonymised with T. knighti. One species closely related to T. knighti, Trisetica aethiopica (Hirst, 1926), which was recorded in Ghana, Uganda, South Sudan, and Madagascar, is re-described on the basis of its syntype deposited in the Natural History Museum, London, UK. This specimen is designated as lectotype.