Mite composition in nests of the Japanese wood mouse, Apodemus speciosus (Rodentia: Muridae).

Acari is a diverse group of arthropods that include well-known parasites of animals. Rodents, particularly, serve as common hosts of mites and ticks, transmitting pathogens to domestic animals and humans. Understanding the ecological dynamics between parasites and rodent hosts is crucial for ecosystem management. Due to limited knowledge about the life history of ectoparasites in wild mouse nests, we collected four nests of Apodemus speciosus, the most common rodent species in the wild areas of Japan, along with soil samples near the nests to study arthropod communities. Mites overwhelmingly populated the mouse nests, comprising approximately 90% of all arthropods, while both mites and collembolans were prevalent in soil. Various species identified in our study, such as those from the families Laelapidae, Pygmephoridae, Cheyletidae, Trombiculidae, Glycyphagidae, and Thyrisomidae align with known ectoparasites or species found in the nests of other rodent species, but most parasitic species were never collected in the surrounding soil except for trombiculids. The dominance of mites in mouse nests suggests selective preference for inhabiting these host environments, although the exact reasons driving this dominance remain unclear. Further investigations into the food web within mouse nests will aid in characterising faunal composition and understanding the ecological interaction among rodents, mites, and other nest symbionts.