The use of DORMANT OIL ( available at nursery ) can work as well.
Paraffinic Oil - 97%
Target pests: Scale, Mites, Fruit Tree Rollers, Pear Psylla, Whiteflies, Fall Armyworms
* See label for complete list
For use in: Ornamentals, Flowering Shrubs, Shade Trees, Fruit Trees
* See label for complete list
Application: Ornamentals: 3 tablespoons (1.5 oz.) per gallon of water
Fruit Trees: 6 tablespoons (3 oz.) per gallon of water
*Do not apply when temperature exceeds 85 degrees F
* See label for compete application instructions
Good luck