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How To Control Granary WeevilsImage result for granary weevil

Storing too much food in your pantry that you don’t intend on eating anytime soon can be rather risky. One day when looking in your pantry or cupboard hoping to fix up some dinner, you’ll notice to your horror hundreds of little brown bugs crawling out of your food boxes and pouring out onto the floor. One of the notorious culprits that can alarm homeowners in this type of way is the Granary Weevil. This pantry pest is known for contaminating grains and wheat products by laying eggs in the kernels and making the food unfit for human consumption.

Granary weevils are also called grain weevils or wheat weevils and are closely related to the rice weevil. Granary weevils easily stand out with their reddish-brown color looking similar to a beetle. They are cylinder shaped and average between 3 and 5 mm in length. The larvae of granary weevils are the ones that unleash the most damage. They appear to be white legless grubs that are nearly microscopic.

Granary weevils enjoy grains and a variety of dried foods but they can also consume fabrics and books and even wallpaper. Adult granary weevils lay eggs in food and can release eggs rapidly to bring upon a new generation of contaminators. Unfortunately for homeowners, the presence of weevils are nearly impossible to detect until there is a massive number crawling around in your food storage.

If you have a problem with granary weevils in your pantry, there is a way to eliminate them with the help of products we carry here at Solutions Pest and Lawn. We can also help you with how-to advice so you can conduct a control program yourself.

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How to Get Rid of Granary Weevils: 4 Step Solution

Fortunately, once you discover a granary weevil infestation in your pantry or cupboards, it is quite easy to get rid of these pests by conducting a clean out of your pantry. We here at Solutions Pest & Lawn recommend a control approach which includes a thorough clean up of your pantry, applying chemical treatment in the cracks and crevices and setting pheromone traps. Check out our simple to follow steps below to learn how to properly dispose of infestations of granary weevils in your pantry.


Step One:  Identify the source of the infestation and remove the product immediately from your pantry or storage area. We also recommend that all already opened food containers you have be stored in airtight containers made of hard plastic. By doing this step you can prevent further infestation. You will need to completely empty out your pantry and check EVERYTHING. Completing this step properly and being thorough in your approach is half the battle. For the best possible results in eliminating an infestation, we suggest tossing everything in your pantry, even unopened new containers. Don't leave anything to chance.


Step Two:  Once you have decluttered your pantry and removed unwanted foods and foods you feel are infested, vacuum and clean the shelves and surfaces of the pantry. If necessary, use caulking on the cracks and crevices of the shelves and apply fresh paint.


Step Three: Apply a residual insecticide spray. An easy to use aerosol like Novacide Flea & Tick Killer or CB PCO Insect Fogger are excellent options then follow up with an Insect Growth Regulator Gentrol Point Source IGR, which is also available in an aerosol spray and has a crack and crevice tip for easy application.


Step Four: Finally, use pheromone specific traps like X-lure Beetle Floor Trap to catch granary weevils that are moving around in your home and then regularly clean the pantry of any spills and clutter. By capturing the adults you will prevent them from laying any more eggs and continuing the infestation cycle.


Follow these steps as we have laid out and your granary weevil problem will be solved. Browse our granary weevil control products below and if you ever have any questions or concerns, we have pest control experts standing by to assist you via email, phone or online live chat.


Learn More About The Granary Weevil


By just taking a look at our pantry pest section, you can see that there is a wide selection of pantry pests which can find their way into your home or business and put your food at risk for contamination. Though some of the most common culprits in a pantry are Indian meal moths or flour beetles, granary weevils can be just as common in food storage spaces and also just as damaging.


Much like it’s cousin, the rice weevil, granary weevils are a small nuisance but can be quite easy to get rid of once they’re discovered, but the main issue they pose is how quickly they multiply as well as how in just a short span of time and egg can reach adulthood, meaning they can creative a massive infestation at a very rapid rate.


A female granary weevil begins laying eggs pretty much the moment they reach adulthood so once there is granary weevil activity in a pantry, a small number of granary weevils can very quickly grow into a large infestation that will need to be addressed as soon as possible.


Found all around the world, granary weevils are a pest which can be controlled in similar fashion tp other pantry pests which is 1) finding the source of the infestation, 2) discard infested food and then cleaning and sanitizing the pantry and finally 3) applying residual insecticides and traps. The article below will cover this process in detail but if there is anything we don’t cover, give us a call or email with your questions and we’ll try to further assist.


As prevalent as a granary weevil is worldwide, granary weevils are a pest which can be eliminated with the help of a solid pantry pest control program. Control can be successfully accomplished by locating the food source they have gathered in, dispose of the food items they have infested and apply correctly labeled bug sprays and traps.


Follow along as we cover the characteristics and habits of the granary weevil in-depth and go over the control process in detail so you can successfully achieve DIY granary weevil control


Granary Weevil Appearance

Granary weevils are an extremely tiny bug, ranging between 1/16 to 1/8 of an inch long. They are usually colored brown or black and have a spotted thorax and abdomen. As their name clearly implies, the granary weevils are frequently found infesting grains. Be that as it may, granary weevils still have a vast appetite for different pantry foods and will really eat just about anything they can get a hold of .


Granary weevils enjoy many different kinds of seeds, dried beans, cotton, nuts, cereal, any wheat product, corn, flour, pasta, bread and various other oats and grains found in a stored food area. However, granary weevils don’t just limit their diet to what they find in the pantry.


Granary weevils will gladly consume cotton fabric and materials found in furniture and clothing as well as dried flowers and plants, and flower arrangements that are beginning to show age.


What may come as a surprise to most people is that granary weevils have even been found eating up Christmas ornaments, dried flowers which have been gathered and stored clothing. Granary weevils also love to eat fruit as they have been found nibbling on pears, apples, grapes and other types of fruit.


Granary weevils are really good at flying and as a result they may easily enter the home by flying in from outside, lured by the smell of food.


The Granary Weevil Life Cycle

Like many other insects, granary weevils go through a complete metamorphosis. Starting as an egg, hatching into a larvae, going to pupate and then reaching their final form in adulthood. granary weevils begin their lives as an egg which may have been laid by an adult directly in a food source such as cereal or rice or some other grain. Once the egg hatches (which is usually within a couple of days), out comes the larvae resembling a tiny caterpillar.


It is as larvae that granary weevils are the most damaging. Once hatches out of the egg they begin to devour the food around them immediately. The granary weevil larvae will continue to feed for the next 1 to 3 weeks until it’s time to pupate, which they will they start to spin a cocoon to begin the pupation process


Pupation of the granary weevil takes between 1 to 2 weeks and after that the adult granary weevil will emerge from the cocoon. Unlike pantry moths and other pantry pests, granary weevils actually feed on food in the pantry nearly as much as they do in the larvae phase, consuming a large variety of different items.

Because they are good fliers and are small, granary weevils can practically travel to any part of the home with great ease and find all kinds of different things to munch on. Female adult granary weevils will begin laying eggs within 3 days of emerging from the pupae state. It is reported that they can lay between 300-600 eggs during the 3 to 6 month duration of their lives so just one female can end up creating a massive infestation.


Because granary weevils can go through the life cycle in as quickly as a month, they can become a great problem in a short amount of time wherever they have established. If you believe your home or place of business has come down with a granary weevil infestation, there are a number of different tasks that need to be carried out to successfully get rid of them.


Preliminary Inspection and Sanitation For Granary Weevil Control

To begin the process of getting rid of granary weevils you must begin with a thorough inspection and clean up. Start by emptying all our your pantry cabinets, shelving and closets where you have spotted them or believe they have been active.


You will need to go through all your boxed food and check them all for traces of granary weevils. Any item where you see them needs to be disposed of immediately by sealing them in a plastic bag. This will help to contain them until your garbage picked up by the garbage man.


The smart thing to do if you discover an infestation is to throw away EVERYTHING you have in your pantry, so you can ensure that the granary weevils will be eliminated from your food.  This may not sound like an appealing option but you don’t want to leave any food item to chance.


If you don’t want to throw out all your food, inspect everything (which will be time consuming). Open all your boxes, even ones that are brand new and unopened and check. If there are some that you aren’t sure about, place the item in a plastic bag and seal it. If there are granary weevils in the suspected item, they will try to escape after some time. In this case, toss the food item away immediately. If nothing comes out, you can safely assume that the food is not contaminated or infested.



The Best Methods of Chemical Treatment for Granary Weevils

Once the entire pantry has been emptied out and you have discarded the infested foods the granary weevils were in, you can then move on to insecticide treatments.  


We highly recommend prior to using any pest control products that you first vacuum the entire interior of your pantry as well as your cupboards, cabinets and all other previous infested areas that will be treated.


This helps by sucking up some granary weevil eggs and pupae that may be resting in a crack or crevice as well as any crumbs or grains that have spilled which can be food for a lingering granary weevil larvae.


When laying eggs, granary weevils utilize a secretion that is similar to glue which they use to protect their young, attaching them to surfaces so they won’t be displaced and close to food so when they’ll be hatched and ready to eat, the food is right there for them. Though vacuuming helps, vacuuming alone won’t solve your granary weevil problem.

Best Aerosol Spray To Treat granary weevils

After doing a thorough cleanup, vacuuming and sanitizing of the targeted areas, you can then move on to chemical control. There are a number of products which we recommend for granary weevil treatment, such as an aerosol spray which can easily get into those hard to reach corners, cracks and crevices.


The first option is Novacide Flea & Tick Killer. This product contains little to no odor and works quickly. Use Novacide directly by spraying them in your pantry, cupboards, under the sink and in closets if you’ve seen them trying to eat clothing and fabric. This aerosol spray also comes with a straw applicator tip which you can attach to spray those cracks and crevices where adults and larvae commonly hideout.


Keep in mind that granary weevils are very small, move quickly and hide really well when threatened. Also, since they’re able to fly, they can be difficult to find and kill on contact. That’s why this product has a residual effect. Once you spray, let the place air out and the product dry and after an hour you can place everything back in the pantry.


It may be wise to treat regularly every two weeks until you do not see any more granary weevil activity. One they are gone, you can use Novacide quarterly to keep them gone.


Now if you are not sure where the granary weevils are hiding out, you could go with  CB PCO Insect Fogger. This fogging product can be set up in the pantry and will thoroughly cover all the areas where they are hiding that are hard to get to. You will need to open all cabinets and suspected areas and leave the home for a few hours as the fogging chemicals do their job and fumigate the area.


The Best Product For Treating granary weevil Eggs

Most of the insecticides we recommend will kill adult granary weevils, but not the eggs. For this you will need an insect growth regulator. These work as a form of birth control, putting a halt on the development process so eggs don’t hatch and larvae doesn’t develop. We recommend Gentrol Aerosol Insect Growth Regulator.


It's important to have an understanding of how Gentrol works. An IGR does not kill adult weevils, it only targets granary weevil eggs and larvae. It is essentially not a killer of eggs, it just makes it so they don’t develop and function normally. This is done so be Gentrol mimicking a vital protein the young weevils need to grow and disrupts the life cycle process. This disruption results in the stalling of their development, leading to death and making it so a new generation of granary weevils isn’t produced.


Using Traps To Catch Granary Weevils

Finally, we highly suggest using Pro-Pest Pantry Moth & Beetle Traps for granary weevils. These traps contain strong pheromones or sex attractants to lure adult granary weevils towards it. Once the unsuspecting granary weevil crawls or flies toward the trap, glue like adhesive will capture them and they are toast.


Install these traps after you have treated the area with insecticide. This is also a helpful way to monitor the granary weevil infestation. If you’ve done a good job spraying, the traps may only capture a few granary weevils. If you see a lot on these traps, you may have missed a spot and should retreat the area.


Place these traps in the back of each pantry shelf or cabinet. 1 should be enough per shelf or cabinet. These products last for 1 to 2 months so you may need to replace them until you no longer have a granary weevil problem.


Prevent Granary Weevils With IPM Practices


Once you have eliminated the granary weevil problem, don’t think that you will never encounter a pantry pest ever again. granary weevils are quite a persistent pest and they may make a comeback.


To prevent this from happening make sure to don’t have too much food cluttering your pantries and cabinets. Also make sure to wipe up and clean any spills and toss away old food items that you haven’t been eating. You can spray the products we’ve suggested from time to time as a preventative measure as well as set traps to monitor future activity.


As long as you maintain cleanliness and are diligent about checking your food items, even ones you newly bought from the store, you will keep the granary weevils away for good.

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