Citrus psylla is a bug that affects citrus trees. You’ll know if a psyllid has been in your garden if you see raised swellings and correlated dents on your tree’s leaves. Other ways to identify a citrus psylla infestation is if the new or young growth of your tree is severely malformed or if you find yellow eggs on the edges of young leaves.
An adult psyllid is light yellow and about the size of an aphid with transparent wings. Citrus psylla can occur throughout the year but tend to be most abundant in September and October in accordance with the citrus tree’s growth flush. Also, keep an eye out after you’ve pruned your tree because it stimulates tree growth which is vulnerable to a psyllid attack.
Citrus psylla in itself is not such a major issue. The general health of the tree and its fruit will remain unaffected - especially if it’s a small infestation. The prevalent issue, however, is that citrus psylla is a transmitter of a major citrus disease called ‘African Greening’. Greening results in the yellowing of leaves and the fruit having a lopsided form where one side remains small and green and the other turns orange.
The best way to treat this pest is by destroying the eggs or the psyllid at a young age. So regularly check your citrus trees for symptoms of citrus psylla. When identified, you can use an organic insecticide that contains pyrethrins - make sure to use a long-lasting spray as the eggs usually hatch at varying times.
Insecticides that are effective against scale and mealybug are also likely to suppress citrus psylla for at least two weeks. You can also try encouraging natural predators of the citrus psylla such as ladybugs, birds, wasps and spiders.
Want to learn more about Citrus psylla? Take a look at the insect profile below!