Boxwood Leafminer Treatment Tips

Boxwood Leafminer is a fly larvae that inhabits the leaves of the Boxwood. Found nearly everywhere in the United States, it is known to be the most destructive insect pest of the shrub. 

Your Boxwood shrub can be developing an infestation with Leafminer for months before you may ever know it – unless you are paying close attention to certain signs and taking steps to ensure the health and vitality of your plant. This can give you the best chance of overcoming its damage.

Understanding Boxwood Leafminer

It is important that you contact a Certified Arborist as soon as possible if you suspect that your Boxwood has been impacted by any size Leafminer population. Below are a few signs that may signal an infestation, but to be truly sure, you will need to seek a professional opinion.

Keep an eye out for these signs of Boxwood Leafminer damage: 

• Discolored yellowish leaves
• Dried out, unhealthy appearance
• Premature leaf drop
• Small blisters on the underside of the leaves
• Peel the leaf apart to expose larvae (tiny maggots)
• Skins left behind from the larvae may be dangling from the leaves (common in the Spring)

Finally, adult Leafminers are orange-colored midges that may hang around the area of the infested bush. Give the shrub a shake and you may send them flying. 

Boxwood Leafminer Treatment Tips

Once you have determined that you are, in fact, dealing with Boxwood Leafminer, it is important to seek treatment. There are a few things you can do to successfully save your Boxwood and get rid of the Leafminer altogether. 

Understand the Life Cycle

It is important to understand the lifecycle of these pests – especially when it comes to successfully treating them. Females lay eggs in the underside of the leaves until they hatch.  Then, the larvae move around inside the leaves until they force their pupal skin out and turn into an orange, mosquito-like flying insect. Life goes quickly after this – as they only live for about 24 hours. 

Only one generation of Boxwood Leafminer will occur each year. Having some knowledge about their lifecycle can help you understand what you are looking for and the best way to treat it. 

Shake and Spray

During the spring months – primarily May-June – the larvae begin turning into flying adults. Though they still tend to hang around the bush. When you give it a good shake, all of the midges will take flight. This could be a potentially ideal time to spray them down with insecticide. 

Keep in mind that this option will only be effective for those Leafminers that are out of the leaves. 

Start Pruning

By pruning back your plants about 10% to 30% you are essentially reducing the number of infected leaves you have. This step may not remove all the insects, but it will drastically cut down on the infestation. Just be sure to dispose of the branches and leaves that you cut off by bagging them up securely. 

Call a Certified Arborist

Reaching out to a professional Certified Arborist will help you address the Boxwood Leafminer most successfully. A full assessment and diagnosis will be made and the most adequate insect treatment will be performed. Due to their lifecycle, treatment often involves a systemic approach since this is really the only successful way to combat the Boxwood Leafminer.

Preventive and routine care is also just as important. After all, one that is thriving stands stronger against any threat from pests.

Boxwood Leafminer Treatment at Rick’s Certified Arborists

If you believe you may have an issue with Boxwood Leafminer or have witnessed Boxwood Leafminer damage on your shrubs, contact the Certified Arborists at Rick’s Certified Arborists at (610) 840-2655.