Lilac/Ash Borer – Definition & Detailed Explanation – Tree Diseases and Pests Glossary

What is the Lilac/Ash Borer?

The Lilac/Ash Borer, also known as the Podosesia syringae, is a type of wood-boring beetle that primarily targets lilac and ash trees. These destructive pests are native to North America and can cause significant damage to trees if left untreated. The adult borers are metallic blue-green in color and can grow up to 1 inch in length. They lay their eggs on the bark of trees, and once hatched, the larvae burrow into the wood, feeding on the tree’s inner tissues.

How to identify symptoms of infestation

There are several signs that indicate a lilac/ash borer infestation. One of the most common symptoms is the presence of small, D-shaped exit holes in the bark of the tree. These exit holes are where the adult borers emerge from the tree after completing their life cycle. Additionally, you may notice sawdust-like frass around the base of the tree, which is a result of the larvae tunneling through the wood. Other signs of infestation include wilting leaves, dieback of branches, and overall decline in the tree’s health.

What trees are at risk?

Lilac and ash trees are the primary targets of Lilac/Ash Borers. These pests prefer trees that are stressed or weakened, making them more susceptible to infestation. Ash trees, in particular, are at high risk of damage from emerald ash borers, a related species that has caused widespread devastation to ash populations in North America. It is essential to monitor the health of lilac and ash trees regularly to prevent infestations and protect these valuable trees.

How to prevent and control infestation

Preventing Lilac/Ash Borer infestations is key to preserving the health of your trees. One of the best ways to prevent infestations is to keep your trees healthy and well-maintained. Proper watering, fertilization, and pruning can help strengthen the tree’s defenses against pests. Additionally, you can apply insecticidal treatments to the bark of the tree to deter borers from laying their eggs. If you suspect an infestation, it is essential to act quickly to prevent further damage to the tree.

What are the potential damages caused by Lilac/Ash Borers?

Lilac/Ash Borers can cause significant damage to trees if left unchecked. The larvae tunnel through the wood, disrupting the tree’s nutrient and water transport systems. This can lead to wilting leaves, dieback of branches, and overall decline in the tree’s health. In severe cases, infestations can weaken the tree to the point of death. Additionally, the presence of borers can attract woodpeckers, which can further damage the tree as they feed on the larvae.

How to properly treat trees affected by Lilac/Ash Borers

If you suspect that your tree is infested with Lilac/Ash Borers, it is essential to take action to prevent further damage. One method of treatment is to remove and destroy infested branches to reduce the borer population. You can also apply insecticidal treatments to the bark of the tree to kill any remaining borers. It is crucial to follow the instructions on the insecticide label carefully and apply the treatment at the appropriate time to be effective. Regular monitoring and maintenance of your trees can help prevent future infestations and protect the health of your landscape.