How to Identify Pests That Can Harm Your Ash Tree

The brownheaded ash sawfly is a jet black wasp that does not sting. These wasps emerge from their cocoons in late April.

The redheaded ash sawfly makes its appearance in June. You can find them in the cracks of the ash tree's bark. If they enter the sap and heartwood of the tree, they can completely destroy it.

Aphids can infest some Modesto Ash trees. Look for two types of green aphids, known as the green peach and the melon/cotton. They have tiny, soft bodies with mouth parts that enable them to pierce the ash tree's leaf and then suck out the nutrients. If you have an infestation of aphids, you will also notice a sticky substance on the ash tree's leaves. Adult aphids may or may not have wings.

The ash sphinx is a caterpillar whose larvae can reach 75 mm. On the distal end of the caterpillar, you will find a spine in the shape of a horn. Usually, the caterpillars are light green and have diagonal white or yellow marks on their bodies. These caterpillars do turn into moths, but it is the larvae feeding on the ash's leaves that do the damage.

Ash plant bugs are known to rob seeds, shoots, leaves and buds of their juices. They have soft bodies that are up to 6 mm long. They are an oval shape and have piercing mouths. They come in a variety of colors and have wings.