These 7 Garden Pests and Eggs Are Easy to Remove During Fall Cleanup – If You Know Their Hiding Places

By late October, the vegetable beds are mostly dead vines, and the shrubs are dropping leaves. At that point, fall cleanup is usually just tidying up. Next year's garden pests are still in that mess, though. Squash bugs shelter under the old vines, moths leave egg masses on bark and lawn chairs, and beetles seal their eggs inside viburnum twigs.

Many common garden pests don't die off in winter. They spend it as eggs, pupae, or dormant adults in one spot, and they mostly stay there until spring. That makes them pretty easy to find and remove right now. A pair of pruners, a putty knife, or a rake can take out a whole tent caterpillar colony before it ever hatches.

Where you look depends on the pest. Some hide their eggs inside twigs, while others leave them right out on bark or a fence post. A few of the egg cases and cocoons you'll find belong to beneficial insects, though, and those should stay put.

Why Fall Is the Best Time to Reduce Next Year's Pest Problems

Insects that overwinter usually ride out the cold in a resting stage. For a lot of garden pests, that means an egg mass on a twig, a pupa in the soil, or an adult wedged under leaf litter. Eggs and pupae can't scatter, and dormant adults barely move. Bare branches help too – egg masses hidden by summer foliage are much easier to spot once the leaves fall. One scraped egg mass in October can mean hundreds fewer caterpillars in spring.

So why not rake up everything? Good insects spend the winter in the same spots as the bad ones. Lady beetles and ground beetles burrow into leaf litter, and many native bees tuck into hollow stems. Strip every bed bare during fall cleanup, and those go, too. Focus on whatever had problems this year, and leave the rest a little messy.

7 Pests and Egg Masses to Clear Out This Fall

Here's where some common pests spend the winter and how to clear them out.

1. Squash Bugs

Squash bugs (Anasa tristis) are still around after the plants die. Adults crawl under dead vines and leaf litter for the winter, and some hide under nearby boards. Clear that out once the squash and pumpkins are done. Those vines are prickly, so you'll need good protective gloves like these nitrile-coated garden gloves from Home Depot. Bag the vines rather than piling them up, or the bugs move right in.

2. Viburnum Leaf Beetle

If your viburnums got chewed up this summer, the leaf beetles (Pyrrhalta viburni) probably left eggs in the twigs. You won't see the eggs, just little rows of bumps near the tips of this year's branches once the leaves are off. Those are the caps the females made from chewed bark. Cut the twigs off with sharp bypass pruning shears (these Fiskars bypass pruners on Amazon are good value for money if you need a new pair) and trash them before spring.

3. Eastern Tent Caterpillars

Eastern tent caterpillars (Malacosoma americanum) mostly feed on cherry and apple trees, so start there. Look along the thin twigs for a shiny black band, like someone dripped varnish around the branch. That's the egg mass. Snip the twig off or crush the band, and throw it out. For a big tree, Monterey horticultural oil works as a late-winter dormant spray that can smother the eggs.

4. Spongy Moth

Anyone in the Northeast or upper Midwest has likely heard of spongy moth (Lymantria dispar), once called gypsy moth. Its caterpillars can strip a tree bare in a bad year. Right now, though, they're just eggs, packed by the hundreds into tan, fuzzy patches on tree trunks and fences. Check sheds and the underside of patio chairs, too. Scrape each patch into a bucket of soapy water – a soft-sided tub like this Tubtrugs one from Walmart works well – and let it soak for several days.

5. Iris Borers

Iris borer moths (Macronoctua onusta) lay their eggs on old iris leaves in late summer and early fall, and the eggs wait there until spring. Then the caterpillars hatch, climb the new leaves, and tunnel down into the rhizome. Wait until after a hard frost, since the moths can keep laying until then, and cut away the old leaves. Dispose of the foliage in the trash rather than adding it to your compost pile.

If you've had trouble with iris borers before, consider keeping a spinosad-based insecticide, such as Bonide Captain Jack's Deadbug Brew, on hand for spring, when newly hatched caterpillars are vulnerable to treatment before they burrow into the rhizomes.

6. Scale Insects

Scale insects (Coccoidea) stay stuck to the stems and branches of shrubs and trees all winter. They look like small bumps that come off with a scrape of a fingernail. It could be an adult female, a young one, or a cover with eggs under it, depending on the type of scale. Scrub off what you can, and treat the tiny crawlers with Garden Safe insecticidal soap, available on Amazon. Look over potted citrus before bringing it inside, since scale can keep breeding indoors.

7. Aphid Eggs

Plenty of aphids (Aphididae) get through winter as eggs on rose canes and fruit tree twigs, especially on apples. Those eggs are tiny, black, and shiny, and they're usually near a bud or in a crack in the bark. They're hard to see without a 10x handheld magnifier, like this one with a built-in light on Amazon. Winter pruning gets rid of many, and a dormant oil spray before the buds start to swell can kill more. If some still hatch, a spray of Bonide neem oil from Walmart can help.

Helpful Insects to Leave Alone

Lady beetles, lacewings, mantises, butterflies, and native bees overwinter in the garden too. Don't remove these beneficial insects.

1. Ladybug Clusters

Lady beetles tend to bunch up in winter, and raking into the leaves at the base of a tree can turn up a whole cluster. Cover them back up and move on. Both adults and larvae eat aphids, and every beetle that survives the winter is one more working the garden next year.

2. Praying Mantis Egg Cases

Mantis egg cases look like dried globs of tan foam, sometimes as big as a golf ball, glued to a stem or twig. If one is on a stem, you need to cut below the case and tuck the stem into a shrub, off the ground. Mantises do eat helpful insects, too.

3. Lacewing Eggs and Cocoons

Lacewing eggs are easy to recognize – each one perches on the tip of a hair-thin silk stalk. By fall, you're more likely to find the round, papery cocoons that larvae spin in hidden spots on plants, or adults sheltering in leaf litter. The larvae are voracious aphid predators. Leave both stages in place.

4. Butterfly Chrysalises

Black swallowtail caterpillars spend the summer eating parsley and dill, and the last ones of the year don't leave in fall – they hang on through winter as brown chrysalises, sometimes on the old herb stems. One looks a lot like a scrap of dead plant, so go slowly when you cut those herbs back.

5. Native Bee Nests

Native bees need a winter spot, too. Many of them nest in the ground, and bare soil is easier to dig into than mulch. Leave a patch or two uncovered. Other bees use hollow or pithy stems like raspberry canes, and their young spend the winter sealed inside. Leave those stems standing until spring warms up, then cut them back to about knee height.

A clean garden and a healthy garden aren't always the same thing. Cut the marked twigs, scrape the egg masses, and clear out the old squash vines and iris leaves. Then let the rest of the leaves lie. Next spring should bring fewer squash bugs and more lady beetles.

Pest Control Essentials