Psylla on citrus
Citrus psylla (Diaphorina citri) is a common problem for gardeners with citrus trees. After reading this article, you will better understand why, when, and how to protect your citrus trees against psylla.
An adult citrus psyllid is only approximately 4 mm long and feeds on new shoots of the citrus tree. Their eggs are laid on the tips of growing shoots. The visible eggs are one way to identify if your citrus tree is infected. Psylla can also be identified by malformed new growth or swollen bubbles and dents on your citrus tree leaves.
As the psyllid nymphs feed, they produce a toxin that causes the bubble and dent damage to leaves, preventing normal expansion growth of the leave. Sometimes it is hard to believe that something so small can cause so much damage. Even though the damage cause by feeding is not the main concern. Even more damage can be done by the role the psyllid plays in Citrus greening disease (also known as African greening). During feeding, it opens a path for bacteria, causing the Greening disease. When a citrus tree is affected with this disease, is results in yellowing of the leaves and small, lopsided, or asymmetrical fruit.
When you have identified that your citrus tree is infected with psylla, you should apply Koinor. Koinor is a systemic insecticide that is applied at the base of the tree’s stem for season long control against most aphids and sucking insects. Make sure that you pick off all visible fruit before you apply Koinor. New formed fruit will be ready for consumption.
The best time to apply Koinor is usually mid to end of September, the soil temperature must be adequate for Koinor to be properly absorbed by the tree.
Use product only as directed, follow instructions as per label.