shrub disease - Ask Extension
we have several shrubs with these tiny bugs on the leaves and stalkes . We have tried several sprays but none have worked. Can you provide us with s...
Knowledgebase
shrub disease #210792
Asked September 04, 2014, 6:38 PM EDT
we have several shrubs with these tiny bugs on the leaves and stalkes . We have tried several sprays but none have worked. Can you provide us with some help with picture that we have attached. The last spray that we used was "All Seasons" horticultural spray oil containing mineral oil. It says it kills the eggs by smothering them. It seems like there would be a poison that would be more effective. Your help is appreciated.
Tulsa County Oklahoma
Expert Response
The insect is a scale insect, a euonymous scale, on an evergreen euonymous shrub. These things are tough to deal with. Oils may have some benifit used in late winter to kill eggs, but it has to be a heavy duty oil called "dormant oil". It cannot be used now, it would harm your plant.
I have a reference to an OSU fact sheet which has information about controling scale. Whichever option you choose, I would use Bayer Advanced Tree and Shrub with a chemical called imidacloprid now and yearly. This is applied to the soil around the roots as a drench. The instructions are clear about how to use it. In addition, I would use a spray on insecticide from the list in the spring next year when the eggs hatch.
This insect is so difficult to control on euonymous that some people end up digging up the shrub and planting something different. This scale will not infest or damage shubs other than euonymous.
Hope this helps.
http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2281/EPP-7306web13.pdf
I have a reference to an OSU fact sheet which has information about controling scale. Whichever option you choose, I would use Bayer Advanced Tree and Shrub with a chemical called imidacloprid now and yearly. This is applied to the soil around the roots as a drench. The instructions are clear about how to use it. In addition, I would use a spray on insecticide from the list in the spring next year when the eggs hatch.
This insect is so difficult to control on euonymous that some people end up digging up the shrub and planting something different. This scale will not infest or damage shubs other than euonymous.
Hope this helps.
http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2281/EPP-7306web13.pdf
