Boxwood Leafminers: The Enemy of Your Boxwood Plants!

It’s time to learn about boxwood leafminers, a little pest that causes a lot of damage. It’s important to understand how to identify and manage these destructive insects because they can cause damage to our beloved boxwood plants. So, let’s dive in.

Table of Contents

What are Boxwood Leafminers?

The boxwood leafminer (of the species monarthropalpus flavus) is a tiny insect that lays its eggs on the leaves of boxwood plants. When the eggs hatch, the larvae burrow into the leaves and feed on the inside. As they munch away, they create winding tunnels, which give the leaves a blotchy or bumpy appearance.

Boxwood Leafminers
The scientific name for the Boxwood Leafminers species is monarthropalpus flavus.
Once hatched, the leafminer larvae feed on the inside of boxwood leaves, leaving behind a damaged and unsightly boxwood plant.

How to Identify a Boxwood Leafminer Infestation

It’s important to be able to spot the signs so we can take action and protect our boxwood plants. Here’s how you can identify a boxwood leafminer infestation:

  1. Discolored Leaves. Look closely at the leaves of your boxwood plant. If you notice any leaves that have turned yellow or brown, it could be a sign of leafminer damage. Keep an eye out for leaves that appear different from the healthy green ones.
  2. Distorted Leaves. Sometimes, the leaves affected by leafminers may appear twisted or misshapen. They may look bumpy or have unusual patterns on them. This is because the leafminer larvae tunnel through the inside of the leaves, creating these distortions.
  3. Tunnels or Trails. Take a closer look at the surface of the leaves. If you see winding tunnels or trails that appear as thin, brown lines on the leaves, it’s a clear indication of leafminer activity. These tunnels are created as the larvae feed and move through the leaf tissue.
  4. Tiny Holes. Another sign to watch out for is the presence of tiny holes in the leaves. These holes are where the adult leafminers have emerged after completing their life cycle. The adult leafminers are small insects and can leave behind these exit holes.
  5. Sticky Residue. Sometimes, a boxwood leafminer infestation can cause the leaves to produce a sticky residue. If you notice a shiny, sticky substance on the leaves, it could be a result of the leafminers’ feeding activity.
identify a boxwood leafminer infestation
It’s important to inspect your boxwood plants regularly, especially during the growing season, to catch leafminer infestations early. If you spot any of these signs on your boxwood leaves, it’s a good idea to take action to prevent further damage.

How to Prevent & Treat Boxwood Leafminers

Now, when it comes to dealing with boxwood leafminers, it’s essential to remember that prevention is better than cure. Here are six tips to help keep them away:

  1. Healthy Plants. Start by maintaining the overall health of your boxwood plants. Keep them well-watered, properly fertilized, and ensure they receive adequate sunlight. Healthy plants are more resilient to pests.
  2. Monitoring. Regularly inspect your boxwood plants for any signs of infestation. Look for discolored or distorted leaves, as well as tiny holes or tunnels. Early detection allows for prompt action.
  3. Pruning. If you spot any infested branches or leaves, promptly remove and destroy them. Pruning helps to eliminate the affected areas and prevent further spread of the leafminers.
  4. Natural Predators. Encourage beneficial insects, like ladybugs or lacewings, that feed on leafminers. You can create a welcoming environment for them by planting flowers and herbs nearby.
  5. Water & Fertilize Properly. Maintaining the health of your plants is essential in preventing and recovering from leafminer infestations. Make sure to water your lawn and garden appropriately, providing enough moisture without overwatering. Also, consider fertilizing your plants following recommended guidelines to promote their overall strength and resilience.
  6. Chemicals. Consider an insecticide if your organic solutions don’t work. A local professional or garden center can help you select one that specifically targets leafminers without causing damage to beneficial insects and plants.
  7. Consult a Professional. If the infestation persists or becomes severe, it could be time to seek professional guidance from a local lawn care expert or arborist. They can provide expert advice and recommend appropriate (and safe!) treatment plans as needed.
spraying insecticide to kill boxwood leafminers
It’s not uncommon that a homeowner will get frustrated with the patience required to prevent and eliminate Boxwood Leafminers. To protect your boxwood plants, consider using a professional lawn care expert.

Natural Predators of Boxwood Leafminers

The following are beneficial insects that can lend a helping hand in controlling the population of Boxwood Leafminers in your Cincinnati-area lawn and garden.

  1. Ladybugs. Ladybugs, also known as ladybirds or lady beetles, are colorful insects that love to munch on leafminers. They have a voracious appetite and can devour a great number of these pesky pests. Ladybugs are often considered good luck, and they come in different colors and patterns.
  2. Lacewings. Lacewings are fascinating insects with delicate, lacy wings. They are fantastic hunters that feed on a variety of garden pests, including boxwood leafminers. Lacewing larvae are especially voracious predators and can consume many leafminer larvae in a short period.
  3. Hoverflies. Hoverflies, also called flower flies, are beneficial insects that resemble bees or wasps. They are excellent pollinators and also help control leafminers. Their larvae, known as aphid lions, feed on many garden pests, including leafminers, aphids, and other soft-bodied insects.
  4. Parasitic Wasps. Although the name might sound scary, parasitic wasps are actually quite helpful. These tiny wasps lay their eggs inside the leafminers’ bodies. When the wasp larvae hatch, they feed on the leafminer, eventually causing its demise. They are like secret agents, silently eliminating the leafminers.
ladybugs prevent boxwood leafminers
Ladybugs and other natural predators added to your lawn and garden can prevent damage from Boxwood Leafminers.

By attracting and encouraging these helpful insects, we can create a welcoming environment for them to thrive. Here’s how we can do that:

Final Thoughts

By being observant and knowing what to look for, you can become a Boxwood Leafminer detective and protect your boxwood plants from these tiny troublemakers.

Keep an eye out for discolored and distorted leaves, tunnels or trails, tiny holes, and sticky residue. With a keen eye and patience and persistence, you’ll be able to identify a boxwood leafminer infestation and take steps to keep your plants healthy and happy.

And don’t forget, if it gets too frustrating getting rid of these pests yourself, a professional lawn care expert can safely eradicate and keep them away for good.

Need More Help?

Need a pro to handle your boxwood leafminers’s infestation? Just contact American Landscapes here for a free, no-obligation estimate. Or call us at (513) 947-8727.

You can also learn more about our lawn care applications and treatments, landscaping, and outdoor lighting services by reading our blog. In addition to fertilizer and weed control, we provide mosquito control, lawn aeration, lawn seeding, and much more.