Various worms and insects inhabit and feed off of cherry trees, including worms that are leech-like in appearance. Worms that enjoy the cherry tree as a home are not generally healthy for the tree or the growth of quality cherries.
To learn exactly what type of worm is living in your cherry tree you will need to collect specific information on the appearance and behavior of the animal in question. Once you have this information, you can go online to find out the specific type of worm or visit your local library or bookstore to find books on worms. Resources with pictures are especially useful in figuring out what type of worm you are dealing with and learning the exact steps you need to follow to take care of the problem.
There are several common worms and worm-like insects that live in cherry trees including the tent worm, the cherry slug and canker worms.
Tent worms are known for the white tents they create that look a bit like spider webs. These worms are actually caterpillars and they multiply like rabbits. Active in spring, tent worms nest in many different fruit trees. They create an eyesore and cause serious problems to the trees they live on. One of the easiest ways to get rid of these worms is to remove the branches they are living on. Other options include removing the worms by hand and using a stick or other object to take off the tent like structure.
The Cherry Slug
The cherry slug is also known as the pear slug and it very much looks like a leech. These slugs are actually insects that are well known for the potential damage they may do to many common fruit bearing trees. They have slender bodies and thick, round heads. Dark green, orange and slimy in appearance, the cherry slug begin feeding on trees in mid to late summer and again in the fall. The most damage is generally done by the second generation that comes to life in the fall. Insecticides are effective in treating and removing cherry slugs from a tree. Depending on when it is applied and the severity of the problem, more than one application may be needed.
There are both spring and fall cankerworms that feed on a variety of deciduous tress and shrubs. Cankerworms (also known as inchworms, measuring worms, loopers or spanworms) are present from early spring until fall. The larvae of these worms may be confused for a leech-like worm before they become more recognizable as adults. Adult cankerworms have prologs and look more like caterpillars than leeches. The easiest way to remove cankerworms from a cherry tree is to use an insecticide spray or an horticultural oil spray.