Your Boxwoods Are Under Attack—What Homeowners Need to Know NOW!

If your beautiful boxwoods are suddenly looking a little sad—leaves chewed, branches bare, or covered in webbing—you might be dealing with a sneaky invader: the Box Tree Moth. This invasive insect has officially arrived in Southeast Michigan, and it’s causing serious damage to boxwood shrubs across the region. 

What Is the Box Tree Moth?

The Box Tree Moth (Cydalima perspectalis) is an invasive species originally from East Asia. After spreading across Europe in the early 2000s, it was first spotted in the United States in 2021. By 2022, it had made its way to Michigan. It is rapidly spreading across Southeast Michigan so much so that now it is under quarantine in 13 counties, including Oakland, Macomb, Wayne, Livingston, and Washtenaw.  And what’s on its menu? These moths have a particular taste for boxwood shrubs; those neat, green beauties we commonly use for  hedges, borders, and topiary designs here in Michigan. Unfortunately, the Box Tree Moth loves them even more… as a snack... well more like breakfast, lunch, dinner, dessert, and a snack. 

Why Are They a BIG Problem?

The caterpillars feed aggressively on boxwood shrubs, quickly stripping them of their leaves. Without foliage, the plant can’t photosynthesize properly, which weakens it and can lead to death and potentially killing entire plants in just days.

• Local impact: As of 2025, the Michigan Department of Agriculture has quarantined 13 counties—including Oakland, Macomb, Wayne, and Washtenaw—to contain the spread.

What Does "Under Quarantine" Mean?

You might hear that counties like Oakland, Macomb, Wayne, and Washtenaw are “under quarantine” because of the Box Tree Moth—but what does that actually mean?

Don’t worry—it’s not about people staying home. This type of quarantine is a plant protection measure put in place by the Michigan Department of Agriculture to help stop the spread of this invasive pest.

Here’s what it means for homeowners and landscapers in Southeast Michigan:

• Limited movement of boxwoods: You can’t freely move boxwood plants, clippings, or soil out of quarantined counties unless they’ve been inspected or treated. This helps prevent the moth from hitching a ride to new areas.
• Extra inspections: Nurseries and landscapers may see more frequent checks to catch infestations early.
• Treatment requirements: Businesses must follow specific guidelines to treat or certify boxwood plants before selling or transporting them.

The goal is simple: keep the Box Tree Moth contained and protect landscapes across Michigan and beyond.

This invasive species has been spreading rapidly across the region, and its caterpillars can defoliate entire shrubs in a matter of days. Staying informed about emerging pests like this one is key to protecting your landscape.

Did you know? Not all box tree moths look the same! While the most common form of them have striking white wings with a dark brown border, there’s also a lesser-known brown morph. These moths are almost entirely brown, with just a small white spot on each forewing. Both color variations belong to the same species and can often be found in the same area.

What Does It Look Like?

You’ll spot two types of adult moths:

• White wings with a brown border and a white comma-shaped mark.
• All-brown wings with the same white mark.
  
  

Their caterpillars are the real troublemakers and even more distinctive:

• Greenish-yellow bodies with black heads.
• White, yellow, and black stripes.
• They grow up to 1.5 inches long and feed aggressively on boxwood leaves.
  
  

Signs You’ve Got Box Tree Moths

Here’s what to look for in your yard:

• Chewed or skeletonized leaves.
• Webbing between leaves and branches.
• Green-black frass (a fancy word for caterpillar droppings).
• Clusters of pale-yellow eggs on the undersides of leaves.
• Shriveled or brown foliage, especially in the lower parts of the plant.
  
  Box Tree Moth infestations can be sneaky at first. The larvae love to hide out in the nooks and crannies of twigs and leaves, making them hard to spot. That’s why regular checkups on your boxwoods are super important. And heads up—late summer is their all-you-can-eat buffet season, so keep a close eye during that time!
  
  

What to Do If You Spot Them

If you suspect an infestation here's what to do:

1. Take a few clear photos of the damage or the moths themselves and report it to Michigan’s Eyes in the Field program. It helps track the spread and protect other landscapes. You can report it here.
2.  Don’t compost infested plants! That could spread the problem. Instead, double-bag the clippings and toss them in your regular trash for municipal disposal.

3. Use targeted insecticides to stop the caterpillars in their tracks:

   • Bacillus thuringiensis kurstaki (Btk) – a natural treatment that’s safe for beneficial insects. Apply every two weeks starting in late June.
   • Pyrethroids like bifenthrin – stronger treatments for later in the season, especially in late July and early September when moth activity spikes.

How to Get Rid of Them

If you spot signs of trouble, act fast! Here’s what you can do:

1. Handpick caterpillars and drop them in soapy water.
2. Prune affected branches and bag the debris to prevent spreading.
3. Use insecticides like Bacillus thuringiensis (Bt), which targets caterpillars without harming beneficial bugs.
4. Try pheromone traps to catch male moths and stop reproduction.

For heavy infestations, you may need to remove and destroy the entire plant. Don’t worry—there are great alternatives like holly or thuja that look just as lovely.

Prevention Tips

• Inspect boxwoods regularly, especially June–September.
• Disinfect pruning tools to avoid spreading disease.
• Avoid moving boxwood plants outside of the quarantine zone.
• Keep plants healthy with proper watering and care—they’re less vulnerable to pests.
  
  

How Safari Tree Can Help

At Safari Tree, we’re all about keeping your trees and shrubs healthy year-round. Our 7-step Tree & Shrub Health Defense Program is designed for Michigan’s climate and includes:

• Preventive treatments to stop pests before they start.
• Targeted pest control using safe, effective products.
• Deep-root feeding to strengthen your plants from the inside out and boost plant resilience.
  
  

If you suspect Box Tree Moths are lurking in your landscape, give us a call! We’ll inspect your shrubs, recommend the best treatment plan, and help restore your greenery to its full glory.

Whether you’re seeing signs of damage or just want peace of mind, Safari Tree is here to help. Contact us today for a free inspection and customized treatment plan.

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