Japanese Beetles: How to Get Rid of Them and Protect Your Plants

By the Garden Voila editorial team · Updated October 30, 2026 · How we verify

Japanese beetles are metallic green and copper beetles, about half an inch long, that skeletonize leaves, eat holes in flowers and damage fruit on more than 300 kinds of plants, especially roses, grapes, raspberries, linden, birch, crabapples, beans and basil. Adults feed for about six to eight weeks in early to midsummer, while their C-shaped white larvae (grubs) feed on grass roots in lawns. The most effective home-garden controls are handpicking beetles into soapy water in the early morning, covering prized plants with fine netting during peak flight, and removing beetle-damaged leaves and fruit. Avoid placing Japanese beetle traps near your garden; research shows they attract more beetles than they catch.

Japanese beetle facts

What are Japanese beetles?

The Japanese beetle is a scarab beetle native to Japan, where natural enemies keep it in check. The Wikipedia article on the Japanese beetle recounts how it was first found in the United States in a New Jersey nursery around 1916 and has since spread across most states east of the Mississippi and into parts of the Midwest, Canada and, more recently, isolated areas of the West. Without its native predators, it became one of the most destructive landscape pests in the eastern US. The Penn State Extension guide to Japanese beetles in the home garden notes that adults feed on the upper surfaces of leaves, chewing out tissue between the veins to leave a lacy skeleton.

How do you recognize Japanese beetle damage?

• Skeletonized leaves: lace-like leaves with only the veins left, often starting at the top of the plant in full sun.
• Chewed flowers: roses, hibiscus and hollyhocks may be eaten to tatters, often with several beetles clustered in each bloom.
• Damaged fruit: ripening raspberries, grapes, plums, cherries and peaches are chewed, especially where skin is already broken.
• Brown, wilted canopy on heavily attacked trees such as linden, birch and crabapple by late summer.
• Lawn patches that turn brown and lift like a carpet in late summer or fall, revealing white C-shaped grubs underneath.

Not sure if it is Japanese beetles or something else chewing your plants? Look for the beetles themselves on sunny mornings and afternoons; they are easy to spot. The pest identifier covers other leaf chewers.

What is the Japanese beetle life cycle?

Adults emerge from the soil in early summer, usually late June in the mid-Atlantic and Midwest, and begin feeding and mating. They release aggregation scents from damaged leaves that attract more beetles, which is why they cluster on the same plants. Females lay eggs in the soil, mostly under moist, well-kept lawns, over several weeks. Eggs hatch in about two weeks, and grubs feed on grass roots through late summer and fall, move deeper in winter, return to the root zone in spring, and pupate in late spring. Each beetle lives about 30 to 45 days as an adult, but because emergence is staggered, the feeding season lasts six to eight weeks.

How do you get rid of Japanese beetles?

1. Handpick early and often. In the cool of the early morning, beetles are sluggish. Hold a bucket of soapy water under the branch and tap or brush them in; they drop when disturbed. Doing this daily during peak season greatly reduces damage and the aggregation scent that attracts more beetles.
2. Cover high-value plants. Drape fine insect netting or row cover over roses, blueberries, grapes and young fruit trees during the six to eight weeks of adult activity. Secure the edges. Size netting with the garden netting calculator.
3. Remove damaged leaves, flowers and fruit. Overripe or damaged fruit and chewed leaves give off scents that draw more beetles.
4. Harvest promptly. Pick raspberries, grapes and other fruit as soon as they ripen.
5. Use targeted sprays only if needed. Products containing neem oil or azadirachtin can reduce feeding, and some botanical or synthetic insecticides are labeled for Japanese beetles; read the label carefully and avoid spraying plants in bloom, since many products are toxic to bees.

Do Japanese beetle traps work?

Traps baited with floral scent and sex pheromone catch huge numbers of beetles, which makes them seem effective. But studies at land-grant universities, summarized by Penn State and others, have found that traps attract many more beetles into the area than they catch, often increasing damage on plants near the trap. If you use traps at all, place them well away from the plants you want to protect, at least 50 feet downwind and ideally at the edge of the property, or encourage a neighborhood-wide effort. For most home gardens, handpicking and netting give better results.

Which plants do Japanese beetles prefer, and which do they avoid?

When planning new plantings in areas with heavy beetle pressure, favor plants they seldom touch for key landscape positions, and protect favorites with netting.

How do you control Japanese beetle grubs in the lawn?

Grubs feed on grass roots, and heavy infestations cause brown, spongy patches that peel back like carpet. Skunks, raccoons and moles may dig up the lawn to eat grubs. Healthy lawns with deep roots tolerate about 10 grubs per square foot without visible damage. Check by cutting a one-foot-square piece of sod on three sides in late summer and peeling it back to count grubs. Options include:

• Beneficial nematodes (Heterorhabditis bacteriophora) applied to moist soil in late summer when grubs are young.
• Milky spore disease (Paenibacillus popilliae), a bacterium that infects Japanese beetle grubs specifically; it builds up slowly over several years and works best in warm soils.
• Grub-control products labeled for lawns, timed to young grubs in mid to late summer, used only where counts justify it.
• Raise mowing height and water deeply but less often, since beetles prefer to lay eggs in moist, short turf.

Controlling grubs in your lawn does not stop adult beetles from flying in from neighboring properties, so combine lawn measures with protection of garden plants.

Do any animals eat Japanese beetles?

The NC State Extension guide to Japanese beetle in turf describes the grub stage in lawns and the natural enemies that attack it.

Yes. Birds such as starlings, grackles, robins and cardinals eat adults, and skunks, raccoons and moles dig for grubs. Chickens and ducks happily eat beetles handpicked into a bucket. Two parasitic flies and wasps introduced from Asia, the winsome fly (Istocheta aldrichi) and spring Tiphia wasp (Tiphia vernalis), help suppress beetles in some regions; you may see adult beetles with small white eggs on the thorax, laid by the winsome fly. Leave those beetles in place, since the fly larvae kill them.

Japanese beetles on roses, grapes and raspberries

Roses

Beetles prefer light-colored, fragrant blooms. Cut and bag open flowers during peak season, handpick daily and use netting on special varieties. See our rose garden guide.

Grapes

Heavy leaf feeding reduces sugar in the fruit. Net vines or handpick, and remove damaged clusters. See grape vine trellises for training vines so netting is easier.

Raspberries and blackberries

Beetles chew ripening berries. Pick daily, remove damaged fruit and net rows; see blackberry trellis ideas and raspberry companion plants.

Dealing with more than one problem? Our plant pests and diseases guide lists every insect and disease we cover, organized by symptom.

Japanese beetle FAQ

How do you protect fruit trees from Japanese beetles?

Young fruit trees can be completely defoliated, which weakens them and delays fruiting. Small trees are easy to cover with fine netting during the six to eight weeks of beetle flight; larger trees are harder, so focus on handpicking from the lower branches and accept some leaf damage on established trees, which usually recover. Pick ripening plums, cherries, peaches and apples promptly, and remove any fruit with broken skin, which attracts beetles. Keep trees well watered during summer, since drought-stressed trees suffer more from leaf loss. For sizing netting, use the garden netting calculator, and see dwarf cherry trees for trees small enough to cover easily.

Do companion plants repel Japanese beetles?

Lists of plants said to repel Japanese beetles, including garlic, chives, catnip, tansy and rue, appear in many gardening books, but there is little research showing they protect neighboring plants in practice. Some plants act as trap crops instead: beetles are strongly drawn to evening primrose, four o’clocks and smartweed, and a few gardeners plant these away from the main garden and handpick beetles from them each morning. Four o’clocks are toxic to people and pets, so avoid them where children or animals play. Diversity in the garden still helps by supporting the birds and parasitic insects that feed on beetles.

Is it worth spraying insecticides for Japanese beetles?

For most home gardens, no. Sprays need repeating every few days because new beetles keep flying in, many effective products are highly toxic to bees and other pollinators visiting flowers, and systemic insecticides applied to flowering plants can harm pollinators for weeks. Neem oil and products containing azadirachtin offer modest protection and break down quickly. If you choose a spray for a valuable plant, read the label carefully, apply in the evening, avoid open flowers and never treat edible crops with products not labeled for them.

With daily handpicking during the short adult season and netting on your most valued plants, Japanese beetle damage stays manageable even in heavily infested areas.

Sources: Penn State Extension, Japanese Beetles in the Home Garden; NC State Extension, Japanese Beetle in Turf; Wikipedia, Japanese beetle.

Beetle timing, why traps backfire, and grub control

Penn State Extension’s Japanese beetles in the home garden says adults, about 3/8 inch long and coppery-green, emerge from soil pupae from mid-June to early July. Each female lays up to 60 eggs in the ground over about two weeks, and grubs feed on grass roots, with most damage from late August through early October. Roses and grapes are favourites. Pheromone traps were designed to monitor the beetles’ spread and are not recommended for control: they catch only about 75 percent of the beetles they attract, so the rest feed on your plants.

• Handpick in early morning or evening when beetles are cool and sluggish, knocking them into soapy water.
• Insecticides: insecticidal soap is not effective on adults; neem and pyrethrin are somewhat effective; spinosad is effective but slow. Broad-spectrum pyrethroids, carbaryl and acephate kill adults but harm other insects and should not be applied to flowering plants; systemic imidacloprid harms pollinators.
• Grubs: treat in late summer to early fall, not spring, when grubs are large, deep and feeding little. Beneficial nematodes (Heterorhabditis or Steinernema) are applied after the ground warms in late spring; Btg is effective against all grub species.
• Milky spore builds up slowly in soil and affects only Japanese beetle grubs.
• Lawn care: mow higher, water deeply but infrequently, and consider letting turf go dormant from late June to late July.

Reviewed October 2026. Sources: Penn State Extension, Japanese Beetles in the Home Garden