(Uploaded by Plazi for the Bat Literature Project) Jones, Jason. 1998. Occurrence and abundance of chiggers (Acari: Trombiculidae) on bats (Chiroptera: Vespertilionidae) in eastern Ontario. Canadian Field-Naturalist 112(2): 230-233. At four sites in eastern Ontario, the wings, ears and tragi of 33 of 366 bats harboured chiggers (larval trornbiculids), Leptotrombidium myotis (Acari: Trombiculidae). These bats included 13 of 17 Big Brown Bats, Eptesicus fuscus, 6 of 9 Leibs Bats, Myotis leibii, 13 of 309 Little Brown Myotis, M. lucifugus; I of 30 Northern Myotis, M. septentrionalis, and 0 of I Eastern Pipistrelle, Pipistrellus subflavus. This study documents the first record of L. myotis on M. leibii. Levels of parasitism in E. [uscus were significantly higher, and in M. lucifugus significantly lower, when compared to con specifics captured in Indiana (Whitaker 1973). In eastern Ontario, parasitized female E. [uscus experienced significantly higher infestation intensities than parasitized males and male M. lucifugus were parasitized significantly more often than females. Intensity of infestation may be linked to day roosts, and the presence and abundance of chiggers may be influenced by roost selection.