When you manage your garden, you may see the indication of a few notches on the edges of leaves or scalloped, and only a vein remains.
It’s a pure indication that the garden has a weevil infestation. Besides the grubs are super destructive to the plants and retard growth and finally wilt.
So, it’s a problem for the gardener and should take measures.
That is why maintaining the above citation, to get rid of weevils in your garden, you can use sticky traps, Diatomaceous Earth, or organic pesticides designed explicitly for weevil control.
Besides, the other methods that are effective yet naturally deter them are-
Physical Control:
- Crop Rotation
- Sanitation Practice
- Plants Repelling weevils
- Trap Crops
- Sticky Traps
Biological Control:
- Diatomaceous Earth
- Beneficial Nematodes
- Neem Oil
- Mulching
Chemical/ Synthetic Processes:
- Insecticidal Sprays
- Systemic Insecticides
- Contact Insecticides
However, all of the above methods can not be applied simultaneously.
But reading the benefits and the effectiveness of each technique will help you to select the right procedure to get rid of weevils in the garden.
What are the signs of weevil infestation?
Weevil infestations in gardens can be spotted by looking for some specific signs. Every pest has its own mode of action on plant attack and the nature of damage, and so does it.
You can identify whether your garden is infested with weevils or not by checking-
Holes in leaves and stems:
If you have small, irregularly shaped holes in the leaves and stems of your plants with brown to blackish color then it is supposed to be weevils.
These holes are a sign that weevils have been feeding on them.
Chewed edges or notches on foliage:
Weevils are notorious for their habit of chewing on the edges of leaves, resulting in a distinctive notched appearance.
So, If you notice these chewed edges or notches, it’s likely that weevils are present in your garden.
They have a slender snout with a labrum, a pair of mandibles, a pair of maxillae, and a labium. You search it by insect morphology.
With these mouths, it can easily damage the plants. However, if the weevils are large number then this can be destructive and should need immediate measures.
Presence of adult weevils on plants:
Adult weevils can often be found on the surface of plants, particularly during the evening or early morning. These small beetles have a characteristic snout and can be easily identified by their presence.
Credit: Flickr ( Studio stack: Leaf Rolling Weevil )
Damage to flower buds or fruit:
Weevils have a particular affinity for flower buds and fruit. If you see damaged buds or fruits with irregular holes or feeding marks, it’s a clear indication of weevil activity.
Different Types of Weevil Infestation in Garden
There are approximately 97,000 known species of weevils, which belong to several families, the majority of which are in the family Curculionidae. However, not all weevils directly affect plants.
For the gardener, we don’t need to know all species. Some of the most important weevils to know are-
Type of Weevil | Description and Habits |
Rice Weevil | Size: 1/16 inches long Feeds on grains like rice Particularly fond of whole grains Can survive without food for extended periods Female weevils lay eggs inside grains, and larvae hatch and eat the grain from the inside out Infest pantry items |
Vine Weevil (Otiorhynchus sulcatus) | Small, dark beetle Found in vineyards across Europe Feeds on grapevines and plant roots Can cause serious damage to crops |
Corn Weevil (Sitophilus zeamais) | Snout beetle Dark brown or black with a long slender nose Damaging to stored grains like rice, wheat, and corn |
Boll Weevil | Feeds on cotton plants Lays eggs inside cotton bolls, damaging the plant Can fly long distances and adapt to different cotton plant varieties |
Rose Weevil (Grapholita janthinana) | Serious pest of roses Adults are about five millimeters long with a brown or reddish body Lay eggs inside young rose buds Larvae develop and feed on developing petals, rendering flowers unsellable |
What Are the Primary Prevention Measures for Weevils?
If you have weevils in your garden, use prevention methods to keep them away and your plants healthy.
Here are some primary prevention measures-
First, make sure to regularly clean your garden by removing leaves, grass clippings, and old plant bits since weevils like to hide in these spots.
Next, you can use special covers called floating row covers to protect your plants from weevils while still allowing sunlight, air, and water to reach them.
Another good idea is to plant types of plants that weevils don’t like as much, which are called weevil-resistant varieties.
And lastly, if you see plants that are really infested with weevils, remove them quickly so the weevils don’t spread to other plants.
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Top 10 Methods of How to Get Rid Of Weevils In Garden?
If you’ve ever encountered the frustrating presence of weevils in your garden, you know just how troublesome these tiny pests can be.
But fear not, for there are effective ways to combat these garden intruders and restore the health and vitality of your green space.
Here are discuss the methods that are popular and 90%-99% effective. So start here-
1) Diatomaceous Earth
Diatomaceous Earth is a natural and effective solution that can help eliminate these pests without harmful chemicals.
How does Diatomaceous Earth work against Weevils?
Diatomaceous earth is a fine powder made up of the fossilized remains of diatoms, which are tiny aquatic organisms. When applied to the garden, diatomaceous earth works in the following ways:
- Mechanical action: Diatomaceous earth has microscopic sharp edges that physically damage the exoskeleton of weevils, causing them to dehydrate and die.
- Abrasive properties: As weevils crawl over the diatomaceous earth, it creates friction that further damages their bodies.
- Desiccant action: This powder absorbs the waxy layer on weevils’ bodies, stripping away their protective coating and leading to dehydration.
Step-by-step guide for applying diatomaceous earth in the garden:
Before you choose the products, must ensure that are food-graded substances without harmful chemicals.
The next thing is to identify the infested areas. Different places in the garden are living spots for weevils. Such as-
- Leaf litter
- Under organic debris
- Behind loose bark
- Inside curled-up leaves
- Under plant pots, in the bases, and under benches
After finding the place, sprinkle the powder directly onto the surface of the soil around the infested plants, creating a thin layer.
You should also focus on areas where weevils are likely to crawl or rest, such as the base of plants and the topsoil.
N.B: After rain or heavy irrigation, diatomaceous earth may lose its effectiveness, so it’s important to reapply it whenever the powder becomes wet.
2) Crop Rotation
“Crop rotation is a farming technique where various crops are planted in a specific order on the same piece of land. This method aims to enhance soil quality, optimize nutrient levels, and effectively manage pests and weed issues.“
Crop rotation is a vital practice in gardening that can help effectively minimize weevil, termites populations.
If you do a crop rotation, you disrupt the life cycle of weevils and discourage their establishment.
Here’s why crop rotation is so essential:
Prevents Weevil Build-Up:
Weevils have specific plant preferences, and by rotating crops, you can prevent the build-up of their favorite plants in one area.
This makes it difficult for weevils to find an uninterrupted food source, reducing their populations over time.
Generally garden has the plants that weevils like most are-
- Vines,
- Rhododendron,
- Azaleas,
- Bergenias,
- Heucheras,
- Primulas,
- Cyclamen,
- Hydrangeas,
- Strawberries.
For these crops consult a crop rotation practice with the agriculture extension department. Otherwise,
Breaks Life Cycle:
Simply, weevils lay their eggs in the soil, and the larvae feed on plant roots.
If you rotate crops, you create a disturbance in their life cycle.
Weevil larvae encounter different host plants, interrupting their development and reducing their overall numbers.
Minimizes Disease Spread:
Some plant diseases are specifically transmitted by weevils. These could further make damage such as
- Dutch elm disease
- Erwinia tracheiphila
- Oak wilt
- Alfalfa weevil larvae
So by knowing the system, you can limit the spread of these diseases as you change the placement of susceptible crops year after year.
Soil Improvement:
Different plants have varied nutrient requirements and contribute differently to soil health.
If you grow leguminous plants in crop rotation, it will further give nitrogen and fertility to the soil.
Overall healthy soil promotes stronger plants that are better able to resist weevil attacks.
3) Sanitation Practices
Sanitation is like a shield that protects your garden from weevils.
Weevils don’t like clean and tidy gardens. When you remove their hiding spots and food sources, they’re less likely to stick around.
Best Sanitation Practices
To maintain a weevil-free garden, here are some top sanitation practices to follow:
- Weed Control
- Pruning
- Cleanup
- Watching the Water
- Inspect New Plants
- Tool Hygiene
4) Weevils Repelling Plants
Some plants naturally produce substances that negatively work on weevils. So does if you plant these species in your garden area or corner of the garden, it eradicates the weevils.
However, it is highly effective because it doesn’t need further maintenance. Just plant and take care and get rid of weevils.
You should plant bay leaves, cloves, garlic, catnip, and mints. If possible try the essential oils by their generic.
5) Trap Crops
Trap crops are those crops that attract certain pests and help protect your precious plants like tomatoes, roses, cabbage, and broccoli.
Generally, gardens consist of precious vegetables that you don’t want to hurt by weevils. So plants some garden defender which will work against these insects.
Let’s learn more about these plants that make great trap crops.
- Marigold
- Nasturtium
- Cherry Tomatoes
- Buckwheat Flowers
- Lavender
6) Sticky Traps
Insect behavior, such as finding food, mating, and reproduction, is all affected by color orientation. Due to the phototaxis, these insects are showing this behavior.
And sticky traps are yellow in color.
It is designed to attract and stick with it, especially for flying pests. By the way, the yellow color is also ideal for outdoor visibility for these insects.
Put traps in pest pathways (corners, damp areas) for cost-effective pest control.
7) Beneficial Nematodes
You can use helpful nematodes to manage garden weevils. These tiny creatures enter the weevils through their natural openings and release bacteria that make them sick.
These microscopic worms actively seek out and destroy weevil larvae, effectively controlling their population and protecting your plants.
What Are Beneficial Nematodes And How They Help Control Weevils?
Beneficial nematodes are naturally present in healthy soils. Heterorhabditis bacteriophora nematodes (HB) are species that are good against Weevils, and many other target pests in the garden.
They can burrow the soil from the upper layers of 1 inch to 7 inches or even more.
If you tend to use the nematodes for weevil control, here are some other names that you must introduce-
Nematode | Target Pest | Method of Attack |
Steinernema kraussei | Vine Weevils | Enters larvae through natural openings, attacks them |
Heterorhabditis Bacteriophora (HB) | Japanese Beetles, Grubs, Weevils | Effective against various pests, measures 0.6 mm |
Steinernema carpocapsae | Parasite of Insects | Parasitic nematode attacking a range of insects |
Soil-dwelling larvae of weevils | Black Vine Weevil, Cutworms, Clearwing Borer | Targets soil-dwelling larvae in trees and gardens |
8) Neem Oil
Neem oil is a natural and effective solution for combating weevils in your garden.
It is derived from the neem tree and is widely used in organic gardening. It possesses properties that make it a great choice for controlling weevil infestations.
Here are some of the reasons why neem oil is so effective against weevils:
Contains Azadirachtin: Neem oil contains azadirachtin, a compound that disrupts the feeding and breeding habits of weevils. This naturally occurring insecticide targets the nervous system of weevils, leading to their demise.
Repels Weevils: Neem oil acts as a strong repellent against weevils, deterring them from infesting your garden. It creates an unfavorable environment for weevils, making it difficult for them to feed and reproduce.
Interrupts Life Cycle: Neem oil not only kills adult weevils but also disrupts their life cycle. It affects weevil larvae, preventing them from reaching maturity and causing further damage to your plants.
Safe for Beneficial Insects: Unlike synthetic insecticides, neem oil is non-toxic to beneficial insects such as ladybugs and bees.
Usage: Neem oil can be applied to plants as a foliar spray or soil drench.
9) Mulching
Weevils are attracted to moist soil, so it is important to remove mulch and other hiding places from around plants.
This will make it more difficult for them to find a place to lay their eggs.
Additionally, watering only when necessary will help to keep the soil dry and less attractive to weevils.
As non-flying insects, weevils travel from plant to plant by walking.
This makes the Tanglefoot Sticky Barrier an effective way to control them.
Tanglefoot is a sticky substance that can be applied around the base of plants.
When weevils walk across it, they become stuck and die.
10) Insecticidal Sprays
These sprays contain targeted ingredients to eliminate these pests and protect your plants. It contains organophosphate insecticide like Malathion 57%.
It is effective against a variety of insects along with garden weevils. So the solution and spray over the insect will deter them from the garden.
Malathion is mainly used with a professional skid sprayer or boom sprayer on large garden or lawn areas.
Insecticidal spray can be differentiated into two groups.
- Systemic Insecticides
- Contact Insecticides.
1) Systemic Insecticides
Systemic Insecticides are powerful pest control agents that penetrate plants, providing long-lasting protection against weevil infestations. It will work internally within the plants, providing long-lasting protection against weevils.
Here’s how systemic insecticides work on weevils:
First, you put these insecticides on the soil or directly on the plants. The plants, like tomatoes or flowers, take in these insecticides through their roots or leaves. It’s like the plants are drinking a special bug-killing juice.
Now, when weevils come to snack on these treated plants, they’re in for a not-so-yummy surprise. They end up eating the insecticide along with the plant parts.
But here’s the tricky part for weevils: the insecticide doesn’t just stay in one place.
Nope, it goes all over the plant, even to the leaves and flowers. So, no matter where the weevils are nibbling, they’re getting a taste of this bug-fighting stuff.
This insecticide is like a terminator for the plants because it’s toxic to weevils.
It messes up their nerves or makes it hard for them to have baby weevils.
So, it’s kind of like a sneaky poison for the weevils, but it helps keep our plants safe.
List of the Systemic Insecticides available online :
- Acephate 97up Insecticide
- BioAdvanced 3-in-1 Insect Disease & Mite Control
- Safari 20SG Dinotefuran Systemic Insecticide
2) Contact Insecticides
This works through contact with the weevils and it will damage its skin and body parts directly. It will be less effective against systemic as it is contacted by plants and insects. Also less long residual effects.
KeyTakeway of Contact Insecticides:
- Contact insecticides are pesticides that directly target and kill insects upon contact.
- These insecticides come in various forms such as sprays, dusts, or granules.
- They work by disrupting the nervous system of the weevils, causing paralysis and eventually leading to their demise.
- Highly effective in quickly eliminating weevils and preventing further damage to your garden.
List of the contact insecticides available online:
- Control Solutions Cyonara 9.7 Insecticide
- Tempo Ultra SC 240ml Multi-Use Insecticide
- Sevin Insect Killer Concentrate
11) Other Biological Controls
It offers a natural solution to eliminating weevils in your garden without the use of harmful chemicals.
These eco-friendly methods involve introducing natural predators or using beneficial organisms to control the population of weevils and protect your plants.
Examples Of Biological Control Agents For Weevil Infestation:
Control Method | Description |
Birds | Attract robins sparrows, and wrens to your garden for natural weevil control. |
Bacillus thuringiensis (Bt) | Use Bt, a natural soil bacterium, to target weevil larvae and eliminate them. |
Beneficial Fungi | Employ fungi like Beauveria bassiana to safely infect and kill weevils as a biological control measure. |
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Frequently Asked Questions
How Do You Kill Weevils In Your Garden?
If you want to get rid of weevils in your garden, you can try using some special stuff that won’t harm your plants.
One thing is organic pesticides.
These are like the good guys that fight the weevils without hurting the plants. You can also use neem oil spray, which comes from a special tree.
Neem oil makes weevils stop eating and having babies, so they go away.
What Kills Weevils Instantly?
If you want to zap weevils really fast, you can use things from nature.
High-temperature flow is effective against weevils, and flame guns should be your choice.
Another quick way is freezing. If you put the weevils in the freezer, they can’t move, and they won’t bother your stuff anymore.
What Naturally Kills Weevils?
Nature has some tricks to get rid of weevils.
One is neem oil, which comes from a special tree. It messes up the weevils’ eating and baby-making, so they don’t stick around.
Diatomaceous earth is also natural. It’s like super tiny rocks that scratch weevils and make them dry out and go away.
Cloves, White vinegar, and Bay leaves are also effective in eradicating the weevils naturally.
How Do I Get Rid Of Weevils Completely?
To totally say goodbye to weevils, follow these steps:
Clean Your Pantry: Start by cleaning your pantry really well. Throw away any food that has weevils. That’s where they hide.
Use Tight Containers: Put your food in containers that seal tightly. Weevils can’t get in, so they won’t make more babies in your food.
Freeze or Heat-Treat: If you’re not sure about your food, freeze it for a few days or heat it up above 120°F (49°C). That’ll kill any hidden weevils or their eggs.
Natural Helpers: Use natural stuff like bay leaves or diatomaceous earth in your pantry. Weevils don’t like them, so they won’t come back.
Conclusion
So, by using nature’s tricks and keeping our pantries clean, we can make those sneaky weevils say bye-bye forever. Happy gardening and pest-free snacks ahead! 🌱🐞
Let us know if you have any further queries.
Reference:
https://ipm.ucanr.edu/PMG/GARDEN/FLOWERS/INVERT/weevil.html
I am a graduate of Bangladesh Agricultural University, where I delved into various agricultural disciplines, equipping me with a profound understanding of agriculture. Beyond academics, I have hands-on experience in gardening and crop cultivation. My passion is to embrace sustainable farming and horticulture. With a BSc in Agriculture, I am dedicated to promoting environmentally conscious and efficient agrarian practices.
Bachelor of Science (BSc) in Agriculture (Hons.)
Master of Science. (Sustainable Agriculture & Food Security ) (MS)
Bangladesh Agricultural University