Japanese Maple Scale. Lopholeucaspic japonica
I have knockout roses that are infested with the scale I'm going to dig them up and throw them away can I replant knockouts in the same spot ? Or should I not plan anything that has a woody stem in the same spot ? Is there anything that should be done to the soil or do the scales not affect this soil ?
Japanese maple scale does not spend any part of its life cycle in the soil, so you don't need to worry about that.
June is when this scale's eggs hatch and crawlers starts moving around the plant. If you dig it up, try not to dislodge the crawlers. Gently dispose of it so that crawlers don't fall off and get onto other trees and shrubs--they infest a very wide range of plants. For this reason, you may want to spray the shrubs with a summer weight horticultural oil to kill the crawlers before you dig them up, just so they won't spread to your old plants or any new plants you put in the old rose's spot.