Redbud trees attract a few different kinds of scale insects. These critters typically hatch out from eggs in May. Without knowing exactly which one is affecting your tree, it's impossible to know approximately when egg hatch occurs. In Michigan, this date is usually around May 11-21. The newly hatched insects will crawl around for a little while before settling down in one location. The only time to control scale insects is when they are in the crawler stage. It may not be too late to spray with horticultural oils right now. Be sure to read and follow all instructions on the label of the horticultural oil. What the oil spray does is very effectively clog up the bugs at most any stage.

Adult scale insects are wingless, don't move and do not have a separate head or recognizable body parts. They have an oval or elongated shape that resembles a small round or flattened hump. As scales suck the juices out of the leaves, they exude honeydew that attracts ants.


Oil spray should not be applied when the daily temperature rises above 85 degrees. What the oil spray does is very effectively clog up the bugs at most any stage.

Since your tree may have been weakened by scale insects in prior years, you may wish to consider applying a fertilizer to your tree to keep it healthy.

The link below will give you additional information re. use of horticultural oil sprays.


https://www.canr.msu.edu/news/using_horticultural_oils_on_landscape_plants

It is also possible to control scale insects by releasing
lacewings or ladybugs.

I neglected to mention...horticultural oil when applied as directed on the label will not harm your boxwoods or pachysandra.

I’m sorry; we do not make recommendations for specific products. If you read the labels, you should be able to make an informed decision. Good luck!