June 21, 2014
1 - Spittlebugs may often be controlled by simply washing their protective spittle from the plants on which they are feeding.
Yard and Garden June 21, 2014
I am trying to identify pests on my apple trees. They are leaving foamy spittle on branches. What is this and what is the recommended treatment?
Spittlebugs (also called froghoppers because of the prominent frog-like eyes of their juvenile stage) are not uncommon and produce exactly the symptoms you have described.
According to information published by the University of Illinois Extension website most spittlebugs do not cause enough harm to justify treatment. Where the amount of spittle is undesirable, an insecticide applied under high pressure can be used, but often using a strong stream of water to wash the spittle from plants is sufficient.
The University of Minnesota site provided essentially the same information. They did list "residual insecticide" and soil applied imidacloprid based insecticides (systemic) as possible solutions.
If you choose to use an insecticide, for your safety, be sure it is labeled for use on apple trees. However, I have used the "wash-off-with-water" treatment successfully. Washing the twigs with a strong jet of water to remove the spittle is usually an effective treatment. The spittle is protecting the insects from drying out from their natural predators. When you remove the spittle, even temporarily washing it away, you increase the drying-out of the pest and expose them to predators that feed on them. That will help manage the population of spittlebugs and other insects in your garden. Only if the population of spittle bugs was extremely high and washing with a jet of water from the water hose proved unsuccessful would I recommend insecticide since the damage these insects do is minor and insecticides may result in an increase in more destructive pests by killing natural predators.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!