How To Get Rid Of Acorn Weevils

Acorn weevil grubs can infest and damage acorns. Do you want to avoid them? You just got lucky because we've researched methods on how you can do this!

Eradicating acorn weevils can be difficult since they emerge from the ground during summer, and using an insecticide to get rid of them can be expensive.

However, if you are gathering acorns for seed collection, pick acorn fruits before they drop on the ground and chill them in the fridge to slow down the life cycle of grubs. Then freeze the acorns to terminate the larvae permanently.

Even though there is no lasting way to eradicate acorn weevils, there are ways to control them and the damage they cause. Please continue reading to learn more about acorn weevil control and management.

How To Get Rid Of Acorn Weevils

Getting Rid Of Acorn Weevils

Curculio nucum, the nut weevil, is a beetle, with an especially elongated snout, characteristic of the Curculionini tribe of the weevil family (Curculionidae). Its larvae develop in hazel nuts.

Eradicating acorn weevils and grubs through insecticides isn't feasible since sprays are expensive and insecticides won't go through the nut. But you can try this method if you have the resources.

If you are collecting acorn seeds, gather the nuts before they fall to the ground and immediately put them in the refrigerator. After chilling, put them in the freezer to eliminate the grubs.

One way to safeguard your acorns from weevil grubs is to immerse your nuts in heated water. The intense hotness of the water will kill the grubs before they can cause severe damage to the fruit.

Another way to get rid of grubs is to put them in a bag and with an insect strip. This strip diffuses a suffocating vapor that kills pests, insects, flies, bugs, cockroaches, and beetles. As grubs emerge from the nuts, they will immediately die as they inhale the air in the bag.

As weevil grubs surface from the nuts, you can expect them to die, and you will have grub-free acorns in no time. You can use one strip for a 30-55 gallon bag.

Click here to see these insect control traps on Amazon.

You can also manage acorn weevils by striking your oak tree with a pole and placing a sheet under the tree to catch the weevils as they fall. Spray an insecticide as the weevils start dropping off the tree. Regularly shaking your tree will prevent acorn weevils from infesting your oak nuts.

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Acorn Weevils And Grubs

Adult acorn weevils are brown beetles that grow up to 3/8". The weevil has a long, narrow mouth called a rostrum. In midsummer, female acorn weevils lay their eggs inside acorn nuts using their mouths to bore holes.

These eggs then hatch into larvae called grubs that stay inside the nuts until the fall season. The grubs stay inside the acorn nuts to feed themselves.

As the nuts fall on the ground in late summer, the grub munches a hole from the inside to be able to come out. These larvae enter the soil and stay put for a year or two to develop as mature acorn weevils.

Mature weevils can live for two to three months and mate to produce eggs numerous times. The life duration of acorn weevils depends on their species and conditions that affect their overall health. The average lifespan of an acorn weevil is one to four years.

Float Test For Acorn Weevils

When you see tiny holes on acorn nuts, that's a sign that grubs have been inside the fruits. The larva inside an acorn nut will feed itself, resulting in a useless fruit that won't grow into a tree.

You should conduct a float test to determine whether acorn grubs have been at work. If the acorn nuts float on water, they are spoiled, and you should throw them away.

Acorn Weevil Features

  • The acorn weevil has big dark eyes and a long mouth similar to an elephant's trunk.
  • Weevils connect and commune with other beetles biochemically. The male weevils detect female weevils by smell, creating jerky movements to transmit messages to other weevils.
  • Acorn weevils can grow up to 0.4 inches long.
  • Weevils have wings but cannot fly for long periods. 
  • Adult acorn weevils eat oaks and other flowers in summer.
  • It takes two hours to three days for an acorn weevil to chew an acorn nutshell.
  • Acorn weevils are herbivores.

Are Acorn Weevils Harmful To Humans?

Acorn weevils bring about problems by damaging food and crops, but they pose no physical threat to humans or pets. They can bite humans, but their bite is not dangerous or poisonous.

Are Acorn Grubs Safe To Eat?

Acorn weevil grubs are entirely edible and delicious. They taste best when you cook them over low heat.

Moreover, grubs are highly nutritious, containing protein, minerals, and vitamins. They can be a good source of daily health nutrition for adults.

Common Types Of Weevils

Boll weevil, on leaf with black background

Numerous types of weevils consume various plants and seeds. Here are the nine most common types of weevils indoors and outdoors. 

Boll Weevil

Boll weevils eat flowers and plants, making them extremely harmful. They sleep during winter. The weevils can grow up to six millimeters in size.

Bean Weevil

Bean weevils have a more circular body shape than wheat and rice weevils. They are hairy and blue-green. They will eat any accessible edible items but usually feed on seeds.

Flour Weevil

This weevil, also called the flour beetle, grows up to four millimeters. It consumes flour, cornstarch, and other food items. However, it doesn't eat whole grains.

Wheat Weevils

This type of weevil damages farming and cultivation. Because wheat weevils cannot glide in the air, they feed on stored food instead of available field crops.

Black Vine Weevil

Macrophotography of a Black Vine Weevil (Otiorhyncus sulcatus) with green and black background.

Black vine weevils are common in the northern United States and Ohio. They can grow up to 12 millimeters and feed on plants and trees. Black vine weevils consume the plant's foliage and stalk, while larvae feed on plant roots.

Rose Weevil

Rose weevils grow to five to six millimeters in size and are black and red. This weevil type feeds on blossoms and can bring significant danger to gardeners.

Matured rose weevils devour plant blossoms and lay eggs inside the flowers. If blooms are unavailable, they feed themselves on the plant's stalks.

Rice Weevil

This type of weevil has a reddish to brownish body color and can grow up to four millimeters in size. These weevils do not harm humans but can be very annoying with their eating practices. They feed on rice and other whole grains like cereals and corn.

How To Get Rid Of Weevils

A black vine weevil, Otiorhynchus sulcatus, Family Curculionidae, on a wild privet leaf.

Weevils do not threaten humans physically but are destructive in many ways. You need to control them to prevent damage to crops and food items. Here are several ways to effectively get rid of these destructive beetles.


Prevent weevils from infesting your food by freezing your food upon purchase for at least four days. Freezing your food will kill the weevils and larvae that are already inside. After freezing, place your food outside the fridge and inspect for dead weevils and larvae.

Use Laurel Or Margosa Leaves

Use bay or margosa leaves to effectively kill weevils by placing the leaves in your food container. Neem leaves are known to be sources of organic pesticides and are widely accessible.

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To eliminate weevils, use cloves. Weevils don't like the smell of cloves, and the scent drives them away.

Place cloves in your kitchen areas that you suspect weevils are infesting. You can also put cloves inside storage containers and jars to eliminate weevils.


The most convenient way to get rid of weevils is to put your infested food items in direct sunlight. Weevils love wet, dark areas and can't tolerate heat, so placing food items in sunlight effectively drives away weevils.

Cleaning With White Vinegar

One way to keep weevils away from your pantry and kitchen is to clean those areas regularly. You should wash with soap and water and then use white vinegar to wipe down counters and other spaces.

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Final Thoughts

When not adequately treated, acorn weevils and grubs may cause severe damage to oak trees, acorn nuts, and other crops. Proper control and management of these pests can prevent severe damage. 

Before you go, check out these related posts:

Are Black Vine Weevils Harmful?

Does Vine Weevil Attack Roses?

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