I have remounted many mites in Hoyers over the years, including a few types. Place the slide part with the specimen in a container on a screen over water (not in the water!). After a day or three, the medium will soften to the point where the cover slip can be removed and the specimen remounted on another slide. Hopefully, the specimens on your broken slides are not too small, then it becomes iffy. I don't know if Cobb slides are still made - those were metal holders that held a double cover slip (square) over a hole in the center. After the Munich museum was bombed in WWII, the mite collection of H. Vitzthum was salvaged and remounted in these containers. Otherwise Jim's & Mike's solutions should work.
That's the nice thing about Hoyers. Years ago I received some mites from a colleague in Australia (where they used PVA only). Slides arrived smashed, and nothing I tried would dissolve the PVA.
Stay well! - Barry

On Tue, Jul 21, 2020 at 12:00 PM Lynn Kimsey <[log in to unmask]> wrote:

We recently had slide-mounted types returned to us where two of the slides were broken. These are all mounted in Hoyers. The part with the cover-slipped specimen was not broken, but was broken on either side of the coverslip. Short of remounting the specimens, which we’d rather not do, do any of you have suggestions on how we can conserve these?


Lynn Kimsey

Bohart Museum of Entomology

University of California

One Shields Ave.

Davis, CA 95616

-So many mites, so little time!
Barry M. OConnor                    
Emeritus Professor  & Curator             
Department of Ecology & Evolutionary Biology
Research Museums Center            
University of Michigan                  phone: 734-763-4354            
3600 Varsity Drive                         
fax: 734-763-4080
Ann Arbor, MI 48108-2228          
e-mail: [log in to unmask]