I used to go for hunting on bats, during endless nights, but for scientific purposes of courses ! No victims among bats I swear !
For this reason I am quite familiar with the mites you can find on the bat wings (or more precisely what scientists call the patagium).
I am happy to present you this specimen which is not an adult stage but a preadult one. I would say deutonymph but I am not really sure. This mite was find on Myotis myotis and is much probably Spinturnix cf myoti but I would appreciate confirmation if you are familiar with such mites and the preadult stage.
You may be surprised by the fact that caecums and blood is not visible, which is usually the case in this family (Spinturnicidae), but it has been erased by chemicals to improve the quality of the microscopic mount !
Thanks for your interest !