Plum curculio (Conotrachelus nenuphar) is a small native weevil, about ¼ inch long with a curved snout, that attacks apples, pears, plums, cherries, peaches and other fruit east of the Rocky Mountains. Females cut crescent-shaped scars in young fruit right after bloom and lay eggs inside, causing knobby, scarred apples and wormy, dropping stone fruit. Control centers on the four to six weeks after petal fall: shake beetles onto a sheet, collect fallen fruit, use kaolin clay or fruit bags, or apply a labeled insecticide at petal fall and repeat as the label allows.
Plum curculio fact sheet
| Scientific name | Conotrachelus nenuphar (a snout beetle, family Curculionidae) |
|---|---|
| Range | Native to eastern and central North America, east of the Rockies |
| Hosts | Apple, pear, quince, plum, cherry, peach, nectarine, apricot; wild plum, crabapple and hawthorn |
| Adult | About 1/6 to ¼ inch, mottled brown, gray and black, long curved snout, four humps on the back |
| Larva | Legless, cream-colored grub with a brown head, up to about 1/3 inch |
| Key damage sign | Crescent-shaped scar on young fruit |
| Critical period | Petal fall through about 4 to 6 weeks after bloom |
| Generations | One in the North; a partial second in the South |
What does plum curculio look like?
Adults are small, hard-bodied snout beetles roughly 1/6 to ¼ inch long. Their mottled brown, gray and black color makes them look like a bud scale or bit of bark, and they have four small humps on their back and a long, curved snout about a quarter of their body length. When disturbed, they fold their legs and drop to the ground, playing dead, which is the behavior that makes the “shake the tree” control method work.
The larva is a legless, curved, cream-colored grub with a brown head that grows to about 1/3 inch. Gardeners often mistake it for codling moth larvae, but codling moth caterpillars have legs and leave sawdust-like frass at the entrance hole.
What damage does plum curculio cause?
Damage depends on the fruit.
- Apples and pears: The female cuts a small hole, lays an egg and then cuts a crescent-shaped flap below it to protect the egg. In firm apple flesh most larvae die, but the fruit grows around the scars, becoming knobby, dimpled and misshapen. Many infested young apples drop in June. Adults that emerge in late summer also chew small round feeding holes in the surface of ripening fruit.
- Plums, cherries, peaches and nectarines: Larvae survive in the softer flesh and tunnel to the pit, often causing gum to ooze from the wound. Infested fruit usually drops early or rots, and the wounds let in brown rot.
The University of Wisconsin–Madison Extension plum curculio guide notes that a single female can lay 100 to 500 eggs, mostly during the three to five weeks after bloom, so a small population can damage a large share of a home crop.
What is the plum curculio life cycle?
- Winter: Adults overwinter in leaf litter, hedgerows and woods near orchards.
- Spring migration: They move into fruit trees around bloom, walking in cool weather and flying on warm, humid nights. Activity jumps when daytime temperatures reach the 70s°F.
- Egg laying: Starts as soon as fruit sets and continues for several weeks. Eggs hatch in about a week.
- Larvae: Feed inside the fruit for about two to three weeks. Most infested fruit falls to the ground.
- Pupation: Mature larvae leave the fruit and burrow 1 to 2 inches into the soil to pupate.
- New adults: Emerge about a month later, usually from late July to September, feed on fruit and then move to overwintering sites.
In the North there is one generation a year. In the southern US, a partial second generation can attack peaches and plums in midsummer.
The West Virginia University Extension plum curculio guide has close-up photos of adults, larvae and egg-laying scars that help confirm what you are seeing.
How do you know if you have plum curculio?
- Look for crescent scars. Starting at petal fall, check 20 to 50 young fruits, especially on trees nearest woods or hedgerows, for small, D-shaped or crescent cuts.
- Do a beat test. Early on a cool morning, spread a light-colored sheet under the tree and sharply tap a branch with a padded stick. Curculios drop and play dead; they look like small dried buds.
- Check dropped fruit. Cut open fruit that falls in June and look for small, legless grubs.
- Remember last year. Damage tends to recur on the same trees and orchard edges, so note where you found it.
If you are not sure what you are seeing, the pest identifier compares common fruit pests.
When should you treat for plum curculio?
Timing is everything. The beetles are most active and fruit is most vulnerable from petal fall, when the last petals drop, through about four to six weeks later. Wisconsin Extension advises starting protection around petal fall, particularly with the first warm, humid nights, and continuing roughly every 7 to 10 days for several weeks. Cool springs stretch the egg-laying period, so protection may be needed longer.
Commercial growers in the Northeast use a degree-day model developed at Cornell: protective coverage is maintained from petal fall until about 308 degree-days (base 50°F) have accumulated, when egg laying has largely ended. You can track degree-days with our growing degree days calculator. Never spray insecticides during bloom, when bees are working the flowers.
How do you control plum curculio without chemicals?
Shake or jar the trees
For a few small trees, jarring works surprisingly well. Each morning while it is still cool, spread a sheet or tarp under the tree and strike the branches sharply with a padded mallet or pole. Gather the fallen beetles and drop them in soapy water. Repeat daily from petal fall for about four weeks. It is labor-intensive but costs nothing and spares pollinators.
Pick up dropped fruit
Collect fallen fruit at least twice a week in June and destroy it by bagging it in the trash or burying it deeply. This removes larvae before they pupate in the soil and reduces next year’s population. Composting does not reliably kill them.
Kaolin clay barrier
Kaolin clay (sold as Surround and similar products) is a fine white clay sprayed on the fruit and leaves. The film makes trees less attractive and harder for the beetles to grip and lay eggs on. Start at petal fall, cover thoroughly and reapply after heavy rain, typically every 7 to 10 days for several weeks. It is approved for organic production and is one of the best options for home growers who want to avoid insecticides.
Fruit bagging
Thin apples to one per cluster when they are about the size of a marble, then slip a small paper or nylon “footie” bag over each fruit and close it around the stem. Bags block curculio and several other pests. They take time to apply but work well on small trees.
Clean up wild hosts and edges
Abandoned fruit trees, wild plum and hawthorn near your garden act as reservoirs. Remove unwanted wild hosts where practical, keep grass mowed under trees and prune trees to an open canopy. Adults can travel more than a quarter mile, so this helps most in combination with other methods.
Chickens and ducks
Poultry foraging under trees in June eat dropped fruit, larvae and beetles. They help reduce numbers but rarely provide control on their own.
What insecticides control plum curculio?
Home orchard fruit-tree sprays that list plum curculio on the label can be used at petal fall and again at the interval stated on the label. Which active ingredients are available to homeowners varies by state and changes over time, so check your state extension fruit spray guide each year. Wisconsin Extension cautions that some insecticides, such as pyrethroids and carbamates, can lead to mite outbreaks, and recommends using as few sprays as necessary and rotating modes of action. Sprays work best when combined with sanitation and monitoring.
Pesticide label note: The label is the law. Use only products registered for your fruit and for plum curculio in your state, and follow the label for rate, timing, protective equipment, re-entry and pre-harvest intervals. Do not spray during bloom or when bees are active, and keep sprays away from water, children and pets. Learn how to read a label on the EPA pesticide labels page.
Which fruit trees are most affected?
| Fruit | Typical damage | Notes |
|---|---|---|
| Plum | Larvae in fruit, early drop | Native wild plums are a main host |
| Peach and nectarine | Wormy fruit, gumming, brown rot entry | See our peach tree and nectarine tree guides |
| Cherry | Larvae in fruit, drop | Sweet and tart cherries both affected; see cherry fruit tree |
| Apple | Crescent scars, knobby fruit, June drop | Larvae usually die, but fruit is deformed |
| Pear and quince | Scars and deformities | Usually less severe than apple |
West of the Rockies plum curculio is rare, and some regions treat it as a quarantine pest, so do not move fruit, soil or nursery stock from infested areas into those regions without checking the rules.
Plum curculio vs other fruit pests
| Pest | Sign | Difference from plum curculio |
|---|---|---|
| Codling moth | Hole with brown frass, tunnel to the core | Caterpillar with legs; no crescent scar |
| Apple maggot | Pinprick holes, brown winding trails in flesh | Attacks in mid to late summer |
| Oriental fruit moth | Wilting shoot tips, larvae in peaches | Caterpillar; shoot damage in spring |
| Stink bugs | Dimpled, corky spots | No crescent cut or larvae |
For leaf problems on peaches at the same time of year, see peach leaf curl.
Can you eat fruit damaged by plum curculio?
Yes. Scarred apples and pears are safe to eat; cut away the damaged parts. Wormy stone fruit is unappetizing but not harmful. Use lightly scarred fruit for sauce, cider or drying.
Plum curculio control calendar for home orchards
| Time | Tree stage | Action |
|---|---|---|
| Late winter | Dormant | Prune for an open canopy; clear leaf litter and brush along nearby fence lines |
| Bloom | Flowers open | No insecticides; bees are working. Prepare tarps, bags or kaolin clay |
| Petal fall | Last petals drop, fruit sets | Start jarring, kaolin clay or a labeled spray; begin scouting for crescent scars |
| 1 to 6 weeks after petal fall | Young fruit sizing | Repeat kaolin or sprays at label intervals and after heavy rain; jar trees daily |
| June | June drop | Collect and destroy dropped fruit twice a week; thin and bag remaining fruit |
| Late July to September | Harvest | Watch for round feeding holes from new adults; pick up fallen fruit |
| Fall | Leaf drop | Remove mummified fruit and fallen fruit; note which trees were hit hardest |
How do you prevent plum curculio next year?
Plum curculio returns every year to the same places, so prevention is about breaking the cycle. The most effective habits are removing every dropped fruit in June, so larvae never reach the soil, and protecting the fruit for the full four to six weeks after petal fall, not just once. If wild plums, abandoned apple trees or hawthorns grow at the edge of your property, they will keep supplying new beetles; managing or removing them helps, as does keeping a mowed strip between woods and your fruit trees. Small, well-pruned trees are easier to jar, spray thoroughly and bag, so dwarf and semi-dwarf trees are a practical choice in areas where curculio pressure is high. Keeping a simple record of which trees showed scars, and when, lets you start protection on time next spring.
Is plum curculio worse on some fruit varieties?
No common apple, peach or plum variety is truly resistant, but early-blooming trees and trees closest to woods are usually hit hardest because they are the first fruit available when beetles arrive. Smooth-skinned fruits such as plums, nectarines and cherries tend to suffer more than fuzzy peaches. Late-ripening stone fruits can also be attacked by the partial second generation in the South. Choosing disease-resistant varieties still pays off, because trees that need fewer fungicide sprays are easier to manage with kaolin clay and sanitation alone.
Planning more fruit? Browse every variety, planting and care article in our complete fruit tree growing guide.
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Frequently asked questions
What does plum curculio damage look like on apples?
Small, crescent-shaped scars on young fruit that grow into knobby, dimpled, misshapen apples. Many damaged apples drop in June.
When do you spray for plum curculio?
At petal fall, after bees have finished with the flowers, and then at the label interval for about four to six weeks.
Does kaolin clay work for plum curculio?
Yes. Kaolin clay starting at petal fall, reapplied after rain, deters egg laying and is approved for organic growers.
How do I get rid of plum curculio naturally?
Jar trees over a sheet each morning, collect dropped fruit twice a week, bag fruit and use kaolin clay.
Where does plum curculio live in winter?
Adults overwinter in leaf litter in woods, hedgerows and fence lines near fruit trees.
Is plum curculio found in the western US?
It is native east of the Rocky Mountains and rare in the West, where it is watched as a quarantine pest in some areas.
Last reviewed October 2026. Key references: University of Wisconsin–Madison Extension, Plum Curculio; West Virginia University Extension, Plum Curculio; US EPA, Pesticide Labels. Check your state extension fruit spray guide for current products.
