In our urban landscapes, pest outbreaks occur more frequently than in natural habitats such as wooded forests. These pest outbreaks occur from urbanization processes such as buildings and roads that can disrupt the balance of natural enemies and plant feeding mites. This disruption of the ecosystem can lead to fewer beneficial mites which results in giving herbivore mites an advantage. To help suppress the herbivore mite population a predatory mite can be released on the plant.
I recently did a predatory mite release on a few boxwood plants to suppress a herbivore mite called the boxwood spider mite. With a small jar I shake it three times to release around 25 predaceous mites on each boxwood. The predaceous mites find, kill, and feed on the boxwood spider mites damaging the boxwood. Boxwood spider mites have signs of a stippling color pattern on the boxwood leaves from ingesting sap. One way to check if the predatory mites are doing their job is see if there is a stippling color pattern on the new leaves that have grown after the predatory mites were applied on the boxwood. The stippling color pattern should be reduced on the new leaves compared to the older leaves on the boxwood.
For large trees you can apply predatory mites to the trunk or near the ground and they will quickly walk to the tops of trees.
Predaceous mites are not the only type of biological control Bartlett employs on ornamental landscapes. Convergent lady beetles, green lacewings, and praying mantis are all natural enemies that can be released on ornamental landscapes to suppress insects that feed on trees and shrubs.