Borers attack flowering cherries. Keep trees healthy with regular fertilizer applications. Scales of several types infest Prunus. Identify the scale for proper timing of crawlers.
Spider mites cause yellowing or stippling but are very difficult to see.
One defoliation may not be serious and small nests can be pruned out and destroyed. Use pesticides when webs are first seen and insects are still small. This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This information becomes public property upon publication and may be printed verbatim with credit to MSU Extension.