Late Fall Pest Watch: What’s Still Active in Your Trees & Shrubs?

As the leaves fall and the chill sets in across Southeast Michigan, you might think your trees and shrubs are finally getting a break from pests. Not so fast! While many bugs have gone dormant or died off, some sneaky pests are still active—or quietly preparing for a winter takeover. November is a critical time for homeowners to stay alert and protect their landscapes before winter fully arrives.

Let’s dive into the late fall pest lineup and what you can do to keep your trees and shrubs safe.

Box Tree Moth: The New Menace in Town

If you have boxwoods, this one’s for you. The Box Tree Moth (Cydalima perspectalis) is an invasive pest that’s been wreaking havoc in Southeast Michigan, especially in counties like Oakland, Macomb, Wayne, and Washtenaw. These caterpillars feed aggressively on boxwood leaves and stems, leaving shrubs bare and vulnerable to winter damage.

What to do:

• Inspect your boxwoods for caterpillars or chewed leaves.
• If you notice caterpillars or damage on your boxwoods, you can treat them with a natural pest spray called Bacillus thuringiensis (Bt)
• Hold off on planting new boxwoods until the infestation is under control.
  
• Stay informed—there’s an active quarantine in place for boxwood movement in affected areas.

Want the full scoop? We just published a detailed blog all about the Box Tree Moth, including how to spot it, treat it, and protect your landscape. Check it out here!

Spongy Moth: Watch Out for Hidden Egg Masses

Even though the spongy moth caterpillars are gone for the season, their next generation is already hiding in plain sight. Right now, these pests are laying egg masses—fuzzy, tan-colored blobs that stick to tree trunks, branches, fences, sheds, and even outdoor furniture. If left alone, they’ll hatch in the spring into hundreds of hungry caterpillars that can quickly defoliate your trees.

What to do:

• Look for egg masses on oak trees and nearby surfaces. They’re about the size of a quarter and feel soft and fuzzy.

• Scrape off egg masses plastic scraper or putty knife and soak them a bucket of in soapy water.
• Check oak trees and nearby structures.
• If you’ve had spongy moth problems in the past, consider professional treatment to prevent a repeat outbreak next year.
  

Taking action now helps protect your trees and shrubs before spring arrives—and it’s one less thing to worry about when the growing season kicks off!

Scale Insects & Spider Mites: Still Sucking the Life Out of Your Plants

Just because the temperatures are dropping doesn’t mean all pests have packed up for the season. Some pests don’t mind the cold. Scale insects and spider mites are cold-weather survivors that can stay active well into late fall—especially on evergreen trees and shrubs. These tiny pests pierce plant tissues and suck out the nutrients, slowly weakening your plants before winter even begins.

Signs of Scale Insects:

• Sticky residue (called honeydew) on leaves, branches, or nearby surfaces.
• Black, sooty mold growing on that sticky residue.
• Small, round or oval bumps on stems or leaves—these are the scale insects themselves, often mistaken for part of the plant.
  
  

 Signs of Spider Mites:

• Tiny webbing between leaves or needles, especially on evergreens.
• Speckled or yellowing leaves from feeding damage.
• Fine dust or tiny moving dots—these are the mites, which are hard to see without close inspection.

What to do:

• Apply dormant oil spray in late fall or early winter. It smothers overwintering pests and eggs.
• Prune away heavily infested branches to help stop the pests from spreading.
• Prune heavily infested branches.
• Keep shrubs well-watered until the ground freezes—healthy plants are better at resisting damage.

These pests may be tiny, but they can cause big problems if left unchecked. A little attention now can help your trees and shrubs stay strong through the winter and bounce back beautifully in spring.

Japanese Beetle Grubs: Trouble Beneath the Surface

You won’t see adult Japanese beetles flying around this time of year, but their grubs are still active underground, quietly feeding on the roots of your grass and shrubs. This hidden damage can weaken your lawn and landscape before spring even arrives. If you’ve noticed signs of grub damage—you still have a short window to act before the ground freezes.

Signs of Grub Activity:

• Brown or thinning patches in your lawn, even though you’ve been watering and caring for it.
• Spongy or soft turf that lifts easily like a carpet—grubs feed on the roots, making the grass lose its grip.
• Increased animal activity, like raccoons, skunks, or birds digging in your yard. They’re often hunting for grubs.
• Wilting or stressed shrubs, especially if grubs are feeding on their roots underground.

How to Check for Grubs

• Use a shovel to cut a small square of turf (about 1 foot wide).
• Peel it back and inspect the top 2–4 inches of soil.
• Look for white, C-shaped larvae just below the surface.
• Finding more than 5–10 grubs per square foot that’s a sign of a significant infestation.
  
  

Grub Activity in November

• Grubs (the larvae of beetles like Japanese beetles and European chafers) are still present in the soil during November.
• By this time, they are larger and feeding deeper, which makes them harder to control with treatments but still detectable through inspection.
• Preventive treatments are best applied in late spring to early summer, so November is not the time for those.

What You Can Do Now:

•  Curative grub treatments (like Dylox or BioAdvanced 24-Hour Grub Killer) can be applied in early November before the ground freezes, but they must be watered in thoroughly to reach the root zone where mature grubs are feeding. This is the only time watering is recommended—outside of treatment, avoid overwatering, as moist soil encourages grub growth. 
  
• Avoid unnecessary watering, grubs love moist soil, which creates ideal conditions for grub growth.
• Consider a soil test to check for nutrient imbalances that could make your lawn more vulnerable and check your lawn's overall health
• Plan ahead for next year’s preventive treatment in late spring.
  
  

A little attention now can save you from patchy lawns and stressed shrubs when the growing season returns!

Spotted Lanternfly: Keep an Eye Out

The Spotted Lanternfly (Lycorma delicatula) is making its presence known in Southeast Michigan. It was first detected in Monroe County in 2024, this invasive insect has now spread to Jackson, Lenawee, Macomb, Monroe, Oakland, and Wayne Counties as of November 2025. While it doesn’t harm people or pets, it’s a major nuisance and a threat to trees, grapevines, and other plants.

Even in late fall, adult lanternflies and their egg masses may still be visible, especially on hardwood trees, grapevines, and outdoor surfaces like fences, furniture, and vehicles.

 What to Look For:

• Adults: About 1 inch long with tan wings covered in black spots. When wings are open, you’ll see bright red and black hind wings.
• Egg Masses: Look like smears of dried mud or old chewing gum—it's grayish and waxy. Found on trees, rocks, outdoor furniture, vehicles, and firewood.
  
  What You Can Do:
• Report sightings to the Michigan DNR using Michigan’s Eyes in the Field tool. [michigan.gov]
• Destroy egg masses by scraping them off and placing them in a bag with rubbing alcohol or hand sanitizer.
• Check your vehicles and outdoor gear before traveling—egg masses can hitch a ride and spread the infestation.
• Avoid moving firewood or outdoor items from infested areas to new locations.
  
  

Bonus Tip: Don’t Prune Oaks Now!

If you have oak trees, do not prune them between April and November. This is prime time for oak wilt to spread via beetles attracted to fresh wounds. Wait until winter to prune safely.

Fall Isn't Pest-Free

Just because the bugs aren’t buzzing doesn’t mean your trees and shrubs are safe. Late fall is a strategic time to inspect, treat, and prepare your landscape for winter. A little effort now can prevent big problems come spring.

Need help identifying pests or planning treatments? Safari Tree’s certified arborists are here to help. Reach out for a free consultation and let’s keep your trees healthy year-round!