Bryobia mites, possibly Bryobia praetiosa Koch, also known as clover mites, are plant feeding mites in the Tetranychidae spider mite family. On occasion, their populations can flare up and they can reach damaging populations on a variety of plants, particularly in protected areas. These mites can also enter structures and become a nuisance pest. They are not considered a threat for bites or spreading disease indoors but can cause unsightly stains when crushed.
I recently found a population of these mites when I noted damage on an Arum italicum planting alongside a house foundation. They had also moved onto a small volunteer money plant, Lunaria annua.
Web Resources
Genus Bryobia BugGuide
Gomez, C. and R. Mizell. Clover Mites. Featured Creatures. University of Florida. One of the best web articles I've found on these mites.
Orginal publication: 4/28/16
Author: R.L. Rosetta, Extension Nursery Integrated Pest Management, Department of Horticulture, Oregon State University
Page last modified 4/28/16
Bryobia mite colony feeding on Arum italicum
Bryobia adult