Smith’s stops dripping trees caused by insect pests found in the San Francisco Bay Area and the Monterey Bay Area
It is important to note that some trees naturally drip sap or nectar and there is no treatment.
Primary causes for trees showing signs of leaf damage, tip dieback, or to dripping sugary sap or other “sticky substances” are:
- Aphids
- Scale
- Thrips
- Mealybug
- Spider mites
- Filbert weevil in oaks (oak trees dripping may also be from aphids)
- Alcoholic flux (aka Wetwood)
There are numerous insects that infect trees, especially trees that are stressed due to drought, compacted soils, harsh growing conditions such as parking lots or over watered lawns. Treating the insect is only one step in helping the tree. If possible, corrective action should be taken to improve the trees health. Healthy trees are less susceptible to insect pests and therefore will not drip sap on patios and cars as readily.
All of the above conditions are caused by insects feeding on the trees. These insects often attract wasps and yellow-jackets (hornets) as well as ants who feed on the sugary excrement that aphids and scale excrete or feed on the aphids and scale insects themselves. Trees dripping sugary sap are host to many inject life forms and treating with insecticide should take into account the effect that it will have on beneficial insects. By direct injection of insecticide into the tree, there is no need to spray the leaves and this will have a big effect on preserving the beneficial insects.