Hello,

There are different types of systemic and they require different directions. Follow the directions on your bottle and don't apply another dose if it doesn't say to. It's hard to say if the scale is completely eliminated. They are very hard to get rid of. It helps greatly that we are starting the growing season off with rain and normal temperatures so the tree isn't stressed.

It's a "wait and see" scenario. I think it's entirely possible that the system may be affecting the plants around it.

https://entomology.ca.uky.edu/ef431#:~:text=Treating%20with%20Systemic%20Insecticides&text=Timing%20is%20important%20when%20choosing,provide%20control%20the%20next%20year.

https://xerces.org/systemic-insecticides-reference-and-overview

I recommend using a dormant oil spray early next spring. I would do it every year as a preventive.

I hope this helps,

Sally Granath

St. Louis County MG