Weevils have a way of surprising you, turning up on your pantry shelves or in a bag of pet food you just bought at the grocery store. They’re tiny, black or red bugs with a long pointy snout and they multiply like rabbits. They can explode from a handful to hundreds, seemingly overnight.
Their reproductive ability makes it difficult to control them once they get a foothold. That means as soon as you spot them you need to identify them to make sure what you’re dealing with, then snuff ‘em out before their population explodes.
The good news is, if you move fast and know what you’re doing, it can be easier than you think. So, if you want to know how to get rid of weevils, you’ve come to the right place. Keep on reading and we’ll turn you into your own DIY expert.
This Pest Strategies guide will cover the following:
- What is a weevil?
- What does it look like?
- How to get rid of weevils
- And more!
If you’re short on time, click here to jump straight to our tips and tricks for ridding your home of weevils.
If trying to exterminate weevils on your own becomes too challenging, we recommend Orkin, Terminix, and Aptive. These exterminators have some of the best trained professionals that are able to use traps, baits, and other chemically treated solutions that are often more effective than standard DIY methods.
Ed has been working in the pest control industry for years helping 1,000's of homeowners navigate the world of insect and rodent management. He manages Pest Strategies now helping homeowners around the world!
Table of Contents
What Attracts Weevils in the First Place?
Grain weevils (Sitophilus spp.) come in three basic varieties; granary weevils, maize weevils, and rice weevils. They are naturally attracted to grain products, corn or corn meal, maize, and dry food. Flour weevils are so named because they’re found in kitchen cabinets infesting various food products.
Stored whole grains in silos are prone to a weevil infestation. While in food storage bins, a female weevil will lay eggs in the grain products. When the grains are taken to be processed, some of the adult weevils and many of the eggs will survive.
They’ll wind up in food items that are in sealed containers you wouldn’t think they’d be able to penetrate. And they didn’t. They were already infesting the grains before they were sealed inside the plastic containers you get them in at the grocery store.
So, what attracts weevils in the first place? Nothing. These pantry pests aren’t attracted to your pantry or house per sé. You put them in the pantry without even knowing it when you brought them home from the store.
There’s not much you can do about it either. The federal government has set standards for different types of grains and how many weevils can be in it before it has to be sold “as is”. Below that threshold, there can be weevils in the grain and it’s still legal.
Weevil Life Cycle
Adult weevils are flightless, usually dark or gray, with curved snouts and elbow-like antennae. They’re generally less than 4/10″ long. A female weevil can lay up to 500 eggs which hatch into white larvae that feed on the plants where the eggs were laid.
Their population hits its peak during summer and early fall when grain harvesting is at its height. The grain, with the eggs, larvae and adult weevils in it is taken to silos for storage, then shipped to the factory to be ground into meal.
Check out the video below for more information on the lifecycle of a weevil.
The best suggestion for getting rid of weevils
Raising the temperature to 140ºF for 15 minutes or lowering it to 0ºF for three days is the easiest, most effective method of controlling weevils. Furthermore, it’s the only one that works 100% of the time.
Find A Local Exterminator
Six Natural Remedies to Get Rid of Weevils From Inside Your House
Because so many people are concerned about pesticides and chemicals, let’s look first at some natural, non-chemical methods of pest control for a weevil infestation. One of the easiest ways to kill weevils without losing your grain is to raise or lower the temperature.
Weevils are susceptible to temperatures over 140ºF or below 0ºF. To save a small quantity of grain or flour, heat it to 140º for 15 minutes. Don’t leave it in the heat for longer than that or it will start to cook. Let it cool then put it in an airtight container.
You can also freeze them out. It takes three days at 0º to kill all the weevils but they can’t possibly survive it. After you’ve heated or frozen the grain or flour it’s safe to use. The dead weevils are so small they can’t hurt you if you swallow them.
You could also sift the flour to get rid of the bodies of any adult weevils.
If you have one container in your pantry that is infested but you’re sure the rest of your stored food isn’t contaminated, put the safe food into airtight containers. Weevils are small but they’re not that small. They can’t get through an airtight seal.
After you’ve cleaned out the food products that infested, continue to keep your food in airtight containers until you’re sure all the eggs have hatched. You don’t want to give the next generation an available food supply. Six to eight weeks is the minimum.
Vacuuming & Cleaning
If you prefer to throw out any contaminated dry food products, you’re still not out of the woods. Weevils are often found crawling out of the box or bag they came in and exploring the cracks and crevices of the shelving in your pantry.
Get in there with a good vacuum cleaner. Use the corner attachment to get down in the corners and edges of the shelves where there are plenty of cracks and crevices weevils can lay their eggs in. Vacuuming alone won’t solve the problem though.
Once you’re finished, and you’ve emptied the vacuum cleaner outside, get a bucket of hot soapy water and wash all the shelves. Put a disinfectant soap in the water or spray the shelves with a disinfectant after they’re dry.
Weevils don’t like the smell of bay leaves. Many people swear the odor of a bay leaf is an effective repellent. They recommend putting a bay leaf or two in each container of grain, cereal, or flour in your kitchen pantry. No matter what species of weevils you’ve got, the bay leaves will supposedly drive them away.
This is mainly for situations where you’re trying to keep weevils from spreading from one grain product to another. If you catch the infestation during the early stages, bay leaves will be very effective. If you don’t, population pressure will force the weevils to overcome their distaste for bay leaves.
However, we haven’t been able to find any scientific research to back up this claim. It may be true – anecdotal evidence is still evidence – but we can’t verify it.
Diatomaceous earth is made from the fossilized remains of microscopic sea creatures called diatoms. It’s an edible product that can be used for digestive problems, as a replacement for sand in swimming pool filters, and as a method of pest control.
How’s that for multitasking?
Diatomaceous earth acts as a desiccant on insects, sucking the moisture out of them and killing them by dehydration. The individual fossils are also razor-sharp, cutting the shells of any insect that walks across it, accelerating the process of killing them.
Spread a thin layer of this powder on each shelf in your pantry. When the weevils try to cross it, it will kill without hours. Best of all, it’s a mechanical method they can’t build up a resistance to.
Pheromones are chemical scents produced by the male or female of any species to attract the opposite sex of their species for reproduction. Deer hunters have long used this principle to attract deer during hunting season by using deer musk.
A pheromone trap for weevils consists of a sticky trap (glue board) with a tab or strip in a sealed plastic envelope. You’ll have to open the plastic envelope, take out the pheromone strip and put it on the sticky board. Weevils will be drawn to it by the odor, get stuck, and die.
The Pro-Pest Pantry Moth Traps is an excellent example of a pheromone trap for use in the kitchen and pantry.
Four Additional Remedies to Get Rid of Weevils From Inside Your House
Licensed pest control professionals know Phantom as a termiticide for killing termites, but testing has shown it is effective against more than just termites. It also eliminates weevils. It takes 3-4 days before you’ll start seeing dead bugs, but it does work.
This aerosol spray is ready to use, so there’s no mixing required.
You’ll need to completely empty the pantry and shelves where your food is stored. Wipe the shelves down with a damp cloth. Let it dry then spray it with Phantom. Once it’s dry you can put everything back in. It won’t hurt your food.
This is another professional pesticide. It’s a broadband pesticide, meaning it kills a wide range of insects and pests. The nice thing about Deltamethrin-based pesticides is the lack of a strong odor. Within minutes, the weak smell will be gone.
You’ll need a 1-gallon pump-up sprayer to mix it in and spray it. Professionals prefer the B&G model made of stainless steel. We know a bug guy who accidentally ran over one of them with his work truck and it didn’t even get a dent in it.
Follow the same spraying procedure as above.
D-Force is also a professional pesticide, used by pest control technicians nationwide. It’s a broadband pesticide with very little odor. It has to be mixed and sprayed in the same way as the one above.
Gentrol needs to be added to both of the pesticides above. It’s an Insect Growth Regulator (IGR) the interferes with the growth of insects, preventing them from maturing and laying more eggs. Think of it as birth control for bugs.
Mix it with the pesticide of your choice. Shake the sprayer vigorously to ensure both pesticides are thoroughly mixed, then spray them together. The first pesticide (the knockdown) will kill weevils that are alive. The IGR will stop larvae when they hatch.
Two Bonus Remedies to Get Rid of Weevils From Outside Your Home
This is a liquid concentrate that can be mixed in a 1-gallon pump-up sprayer. Spray it around the foundation of the house in a continuous band. Spray the grass, bushes, and trees. If you’re on a farm, Phantom is suitable for tank spraying on your crops
This is another Deltamethrin-based pesticide but in a dry powder instead of a liquid concentrate. You’ll need to use a bulb duster to dispense it. Delta dust is an excellent way to treat tiny cracks and crevices around windows, doors, plumbing intrusions, and electrical intrusions.
Shake the duster vigorously before each squeeze, put the tip of the nozzle up to the crack or crevice and give the bulb a sharp squeeze. It will inject a small cloud of dust into the crack, coating it on all sides. Any bug that craws through there is a dead bug.
Best Product Suggestion(s) for Getting Rid of Weevils?
Raising the temperature to 140ºF for 15 minutes or lowering it to 0ºF for three days is the easiest, most effective method of controlling weevils. Furthermore, it’s the only that works 100% of the time.
None of the other methods, including using professional pesticides, works 100% of the time. There will always be one or two bugs that might survive. This is the only way to be sure.
BUT, it only works on small packages of grain or flour. If your weevil problem is bigger than that, your best bet is D-Fense SC and Gentrol in a 1-gallon pump-up sprayer.
How to Prevent Weevils in the First Place?
Modern agricultural practices and field spraying of pesticides keeps weevils from being the problem they were as little as 60-70 years ago. Still, now and then some do get through. Unfortunately, there’s very little you can do about it.
What you can do is sift all of the flour and grain as soon as you bring it home from the grocery store. Many people store their flour products in decorative glass jars anyway, so adding the extra step of sifting it isn’t too much extra work.
If your glass jars have an airtight lid, so much the better. You can see if any bugs are crawling around inside but they can’t escape to spread their infestation. Doing that with all your rice, cereal, meal, grains, and flour products is the best way to stop weevils in their tracks.
Final Thoughts On Weevils
Weevils are a problem but they’re a manageable one. If you take a few sensible safety precautions such as keeping your dry goods in airtight glass jars or clear plastic ones, you’ll be able to keep the weevils under control.
If they’ve already escaped and are spreading, follow our recommendations and you’ll soon gain the upper hand and retake your house.