North American Fruit Explorers mailing list at ibiblio

[Don Yellman <don.yellman@webformation.com>]

Richard:

If the insect damage on your Montmorency cherries consists of little white 
larvae close to the pit, you may have a buildup of cherry fruit fly around 
the tree.  I suffered through these for quite a few years.  Sprays are 
ineffective, and inadvisable on small fruits like cherries.

The best solution I have found is cultural practice.  Be sure to remove all 
cherries from the tree and beneath at the end of the season to keep larvae 
from converting to pupae, which burrow into the ground around the tree to 
await the next season.  In mid to late winter, cultivate around the base of 
the tree out to the drip line with a hoe, to a depth of 3-4 inches if 
possible.  If you have had a bad infestation, do it twice, several weeks 
apart.  This will expose pupae to cold and drying, and kill them.  If you can 
break the reproductive cycle of these insects, they will disappear.  Mine 
have.

Don Yellman, Great Falls, VA