WHAT INSECTS ARE CONTROLLED BY DORMANT OIL TREE SPRAYS?

Spraying trees with dormant oil is one of the first applications we apply. This tree spray is designed to control overwintering insect adults and eggs. Dormant oil can also be used at a lower rate after trees leaf out. Dormant oil tree sprays are desirable to use whenever possible because they control some plant-feeding insects with little impact on beneficial insects. A frequent question we receive from homeowners is “What insects do dormant oil tree sprays control?”

Here is a list of common landscape insects and the level of control that can be expected with dormant oil tree sprays:

INSECT / MITE	CONTROL
Apple aphid on crabapple	Poor
Birch aphid	Poor
Cottony maple scale crawlers	Good
Eastern tent caterpillar	Poor
Elm leaf beetle eggs	Good
Elm leaf beetle larvae	Poor-Good
Euonymus scale crawlers	Good
European pine sawfly	Good
Golden oak scale crawlers	Good
Honeylocust leafhopper	Good
Honeylocust plant bug	Good
Honeylocust spider mite	Poor
Imported willow leaf beetle	Poor
Japanese beetle adults	None
Pine needle scale crawlers	Good
Pine tortoise scale crawlers	Poor-Good
Spruce spider mite	Poor
Sycamore lacebug	Good
Sycamore plant bug	None

None = 0-20% control

Poor = 20-60% control

Good = 60-100% control

The type of landscape plants on your property dictates whether or not your plants would benefit from a dormant oil tree spraying. If you’re not sure if a dormant oil spray would help your plants give us a call. We will have an ISA Certified Arborist inspect your plants and leave you written recommendations on what type of insect, disease, or mite treatments you may need to keep your trees and shrubs free of damaging pests.