Abstract
Free-living mesostigmatic mites collected in coastal forest litter samples in southeastern Brazil were determined to be the nymphal stages of an unknown species of Heterozerconidae, a family whose adults are typically associated with millipedes (Diplopoda) and, less commonly, with squamate reptiles. This is only the second published record of immature heterozerconids and the first positive determination of field-collected heterozerconid nymphs for which the adults have yet to be identified. The protonymph and deutonymph are described, unique morphological characters are discussed, and inferences are made as to the possible identity of the adult stage and its host.