Scale insects are classified as either hard (armored) or soft (waxy). They are occasional invaders of the nursery and landscape setting while being sometimes the hardest to see due to size or coloration. When you walk or inspect your grounds or nursery, take a hard look, as sometimes a scale insect will hide in cracks of the bark and if you’re doing your inspection on the fly, you may not be close enough to see them. Tulip tree scale is a larger scale easier to see from a distance while Japanese maple scale is smaller and can look like an extension of the bark. The color of the bark also helps hide the scale and the newly emerged instar is extremely small. Japanese maple scale can be found on a number of different types of trees, not just maples. The same goes for tulip tree scale. It is often found on southern magnolia, so don’t let the name confuse you. Look at all the trees when doing a walk- thru.
The severity and length of the infestation can usually be determined by the sheer number of scale. For example, Japanese maple scale will typically reproduce about 40-50 a year. Then ask yourself, which side of the tree are they on, north, south, east or west. Is one side more populated than the other? If so, this could have been the initial site. Stop and do a few random fingernail samples to see if they’re still alive as many times they are dead but still attached to the tree. Flip them lightly with your finger nail. Most times they will be moist and will be different colors. For example, they can be whitish-yellow, yellow- pink or purple. They may be dead with no moisture and are blown away with the wind like a feather. Scale insects are not as hard to kill as some pest control companies want you to believe. In most cases this is a way they can command higher fees and instill fear in the property manager to quickly sign an expensive contract. Remember, you’re dealing with a sick tree.
Healthy trees do not get attacked by scale insects. Examine the site. For example, is it new construction with no top soil left, wet areas, wet shaded areas, so on and so on? A simple soil sample can tell you a lot and if you’re dealing with a scale insect, I would also send off a tissue sample to see what is not being picked up by the roots. There are many organic products that can kill scale within 48 hours (temperature-dependent ) in your kitchen at home.