White Pine Aphids

Cinara strobi

I noticed this mass of tiny black bugs on one of my smaller Eastern White Pine trees. As you can see in this picture, there is a large black Carpenter Ant with them too. There are (4) of these Eastern White Pines in a row, each approximately 5' tall, and these bugs are only on one. Coincidently, they're on the one tree that doesn't appear to be doing too good. I believe that the aphids themselves are attracted to trees that are already weakened and stressed versus causing the issues. However, young trees, recently transplanted trees (which ours are) or individual branches on large trees may be killed.

I believe that these black bugs are White Pine Aphids. Aphids suck plant juices from foliage and bark of young twigs and stems. Needles will turn yellow and may curl and become deformed. Aphids also excrete large quantities of honeydew. Honeydew is simply the sap that is sucked in through the beak and only partially digested and excreted. This honeydew is sweet and sticky and often forms on the branches, foliage and twigs upon which sooty molds grow. Ants commonly feed on these sweet excretions. Certain species of ants are often seen scraping the outer bark over which aphid secretions have formed.

I have used the garden hose to spray these critters off but they don't all get removed with this method. I think I will resort to something stronger, something that will kill them so they don't return. I also plan on babying this tree in the hope of saving it and making it stronger, i.e. fertilizer, water - general TLC.