Answer: Based on your description of missing roots, I would first suspect voles have eaten the roots during the winter. However, since you are also seeing a quantity of ants, this may be an unusual case of root aphids attacking the roots of the shrubs. Root aphids are hard to control because they are protected from sprays by being underground. I would suggest you contact your local county extension to see if they can give you a more specific diagnosis, and then based on knowing that, decide what to do. If a chemical control is needed, they will have the most up to date information on what to use and how/when is best to use it for maximum results.
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