Keep An Eye Out For Black Scales
For those of you who have Ponderosa, Austrian and/or Scotch Pines, be on the lookout for little black dots on the needles of your trees. These little guys are called the Black Pineleaf Scales. They are so tiny that most people who don’t know about them never notice them at first. Usually, people notice their pine trees are stressed, thinning out, and turning brown, which can be caused by the scale. At this point, the scales have probably been on the tree for several years, slowly depleting nutrients from the tree.
Under the little black scales, there is an actual insect. This time of year, the newly hatched insects emerge and move to newer growth and other close trees. We call these “crawlers,” which are tiny and hard to see with the naked eye. When they are out from under the scale, they are very vulnerable for about two weeks and can easily be controlled with a general foliar spray. Once they are established and form the shell over them, they need to be treated with a systemic pesticide to kill them from the inside out.
These pests usually spread at a slow rate. Once you see more than five scales per needle, you should start a pest management program to eliminate them. If their numbers surpass the threshold of the tree, then you will begin to see the tree thin out, and needles turn brown.
As mentioned in our other articles, proper watering is the most important thing you can do to keep your trees happy and healthy. When trees get stressed, they are vulnerable to attacks from pests and diseases. If you think you might have scales or have questions, please call our office to schedule one of our Certified Arborists to come out and look at your trees.