Utah State University Extension
Redberry mite is a microscopic pest of blackberry that causes drupelets (small fruit sections) to remain hard and red (or less commonly hard and green) on an otherwise normally-ripened blackberry. The red drupelets can occur from a single drupelet to the entire berry. Redberry mite largely affects late-maturing blackberry varieties. Once it is detected, control is ineffective for that season's crop; control can be obtained in subsequent seasons by a variety of management practices. It was first reported in Utah in 2017 in Davis County
Caron, Michael; Hansen, Sheriden M.; Beddes, Taun; Davis, Ryan; Mull, Ann; Alston, Diane G.; and Nischwitz, Claudia, "Red Mite on Blackberry [Acalitus essigi (Hassan)]" (2018). All Current Publications. Paper 1932.