On Saturday morning we awoke to a rather horrifying sight: hundreds of little brown bugs pouring out of the pantry cupboard and across the kitchen floor. We've encountered ants, pantry moths, and grain beetles but this was a new one for us ... research revealed our new visitors to be grain weevils.
Here's what we've learned about grain weevils and how you can prevent them from invading your pantry…

Due to past insect problems, we're diligent about storing all foods in glass jars or plastic zip-top bags. Unfortunately, grain weevils (Sitophilus granarius, also called granary weevils or wheat weevils) can chew through paper and plastic packaging. That's how they got out of the bag of wheatberries you see above and into the rest of the kitchen.
But how did the weevils get there in the first place? You may want to skip this part if you're squeamish but we think it's actually quite fascinating ... A female weevil lays an egg inside a grain kernel. (She can do this up to 254 times!) The egg hatches and for one to five months depending on the season, the larva lives inside and feeds on the kernel as it grows. Upon reaching adulthood, the weevil emerges from the kernel to mate – and look for new grains to invade. We're kind of amazed to think of this process taking place inside a bag of wheatberries we purchased six months ago and forgot in the back of a cupboard!
That said, we definitely don't want it to happen again and these are the steps we're taking to eliminate and prevent grain weevils from our pantry:
Prevent
• Inspect all grains upon purchase.
• Freeze grains for at least 1 week (or store permanently in the freezer) to kill any eggs.
• Buy grains in small quantities and eat within a reasonable period of time. (We certainly learned our lesson with this one!)
• Store grains in tightly sealed glass, metal, or sturdy plastic containers (not bags).
• Regularly clean pantry cracks, crevices, and shelves.
• Small bags of black pepper placed around the pantry may repel weevils.
Eliminate
• Discard any infested foods. Grain weevils can bore through plastic and cardboard so inspect everything thoroughly. (We chose to be safe and got rid of everything that wasn't already stored properly.)
• Vacuum pantry shelves, cracks, and crevices.
• Wipe shelves with white vinegar.
• Dispose of garbage and vacuum bags outside, away from the home.
• Check regularly for reappearance – it may take awhile to get rid of them completely.
Have you ever dealt with grain weevils? Any stories or tips to share?
• More information: Granary and Rice Weevils (William F. Lyon, Ohio State University)
Related: Do You Have Grain Beetles Hiding in Your Pantry?
(Image: University of Missouri)
Red-and-Pink-Stripe...

I was absolutely DISGUSTED when I bought a bag of rice from the store that had apparently been contaminated with weevils. Disgusted!!
I threw away anything remotely grain related, wiped everything with vinegar within an inch of it's life and transfer everything into small plastic bins. Now, I only buy small quantities of grains (even though it pains me to pay more) and I have never bought grains from that supermarket chain ever again. Disgusting to open a bag and see all those icky flying bugs. Ew!
We ended up with weevils from a bag of garbanzo beans. We now keep all of our whole grains and beans in the freezer. It helps keep the oils in the whole grains from turning rancid too.
I've gotten these in my spices on various occasions. In fact, just last week I was making a salad with smoked salmon and decided to toss in some dried dill-- but ended up tossing in a bottle full of these guys.
The same thing happened to me with curry as well in a bottle of paprika. When I brought back some spices from Morocco last year I froze them for exactly this reason.
Oh so gross :(
After a grain beetle incident, I try to keep everything in glass or hard plastic, clean the shelves regularly and never, ever leave crumbs or flour dust anywhere.
Some might think I'm going overboard but living in a densely populated clutch of buildings where I have no clue how my many, many neighbors keep house, I don't want any potential neighboring BUGS to think I'm giving them an invitation.
I used to buy in bulk from a co-operative and after getting weevils more than once I stopped. We tossed all food that wasn't in cans or jars, vacuumed the pantry (and tossed the bag), cleaned everything with a homemade vinegar and peppermint spray. All grains and legumes that we buy are now frozen for a full week or longer before going into the pantry, and we buy in much smaller quantities.
I know we got the weevils from the co-op because one large bag of grain went from the bag to a brand new plastic bucket with a gamma seal and still had bugs.
I never thought to freeze the grain I purchase. Never had a problem before but will start freezing just to be safe. *shudder*
I bought a bag of calrose rice, the bag was made of paper, when i wanted tu use it, it was full of mini black insects!!! I throwed everything up!!!
So after the freezing the grain or flour can you just use it straight from the freezer or does it need to come to room temperature before using it in recipes (particularly the flour)?
Plaidpants, I think for most recipes, the cold flour would be fine. The exception would be yeast doughs. For these, you want the flour (and all other ingredients) to be room temp.
What I do with my flour is to store a large bag in the freezer and transfer small amounts at a time to a sealed container in my cupboard, refilling as necessary.
Thanks so much for the info! I've never had them (knock on wood!), but I do know that wheatberries will go rancid more quickly than other grains. My food scientist sister shared that bit with me and when I've bought them, I store them in the refrigerator or freezer as a precaution.
If I learned anything in the Peace Corps is that a weevil in your meal just means there's extra protein. And that grasshoppers are chock full of nutrition - twice as much protein as an egg in one grasshopper! And they're kind of tasty fried up....oh....too much information?
grasshopper nutrition
egg nutrition
Wow. I'm kind of surprised at the degree of the "ewwwww! icky! bugs!" reactions here. Kids, they're just insects. Sure, you don't want to eat them, and you want to do all that you can to prevent them. But... chucking out everything in your pantry that could possibly have a weevil in it? That's going a bit overboard.
I thought I found weevils in a bag of flour once, although now after seeing those pictures I wonder. They were just little oat-coloured wormy things, I guess they were the larvae, but I never saw any black bugs. I just sieved the flour several times to get them out, then froze it for a week to kill any eggs. And then I put a couple of bruised fresh bay leaves into the jar when it went back in the pantry; they're meant to detract weevils.
Just... calm down, people. accidentally eating a weevil or 3 during your lifetime is not going to do any harm whatsoever.
I have been putting bay leaves on my shelves for years. I have never had a problem with weevils or bugs of any kind. My grandmother-in-law taught me this over 30 years ago. As an extra measure for flour, I tape a bay leaf to the inside of the cover of my flour jar. Works like a charm.
if you eat one something that has weevil eggs in it but has not hatched can it get you sick?
Cestlaviejess: I guarantee you've eaten unhatched weevil eggs many times and just not known it. They can be found in any grain, so that includes any type of flour, oatmeal, breads and rice.
The Food and Drug Administration provides guidance for the allowable amounts of bugs and such in our food. I have seen estimates that each of us eats 1 to 2 pounds of insects each year without knowing it. In addition the FDA has standards for feces and rodent hair and the like. Their jargon for this is 'Food Defects' the current limits are given in this document:
http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/Sanitation/ucm056174.htm
In the tropics, these little guys are just a fact of life. I remember, when I lived in Singapore as a little girl, it was my job in the grocery store to look through the bags of rice and try to find the one with the fewest weevils. There sure weren't any that were weevil-free. And this was the nicest grocery in the city!
Anyway, they're not that bad, though lots and lots of them are certainly a problem. I keep finding one or two, lately, and it's annoying that I can't seem to locate a source. Thanks for the tip on freezing grain - that'll be my next step.
Throwing out an entire bag of rice because there are weevils is ridiculous. Rice should be washed anyway before cooking til the water runs clear. Any bugs will float to the top. Just wash them out.
Freezing is an excellent suggestion though.
We had weevils get into our cabinet. Had to throw a lot (just about everything) out, but after that all we did was start storing things in glass jars, and that was enough. No need to go berserk with vacuuming and disinfecting.
The bay leaves really seem to work--I do that too. And I freeze my flour (and use it directly out of the freezer).
thanks sillybee! I figured that much, I'm just a paranoid parrot and I get scared those things will pull some live in my stomach and hatch out of me sort of deal even though thats obviously... not possible.
Also - if you find weevils in your pasta, they float to the top when you cook it so you can just skim them off :)
Several years ago, I had some decorative balls in the living room that were covered with different types of beans and grains. One of them had weevils. Thankfully, that was an easy fix--no more decorative tchotchkes with food items glued on them.
The one time we've had weevils in a food item we ate, it was a baking mix. Just threw that box out and was extra-vigilant for a while.
Growing up we periodically had them. My mom treated it like it was a part of life. You get weevils, you get rid of them and try your damnest not to again.
That said as an adult, I haven't ever gotten them (go through flours/ grains too quickly?) but growing up plain ol AP flour was our main culprit. Then they'd go to dog food, rice, you name it. The worst was bags of crab boil (the ones full of spices) you cant easily discern pepper or spices from weevil bodies til its too late!
i know it's not cool to be like, "eww, bugs!" but when you have grain moths flying out of your cabinet every time you open it, it is a little freaky. three months after inspecting all of my pantry and trashing contaminated things, i still get a few flying around.
i am going to tape some bay leaves to my cabinet doors, but this article from care2 indicates that an expert at king arthur flour said bazooka bubble gum will also repel grain moths & weevils!
Similar to the bay leaves, I heard an old folk remedy about putting a dried hot pepper in the containers of grains and beans to repel insects. I did it for a while but then must of forgotten about it. After reading this I think I'll start again :) Maybe trying the bay leaves this time.
cestlaviejess, your stomach juices will kill anything live that you eat. Don't stress about bugs.
Ugh, we had pantry moths for a YEAR before we finally got rid of them. What finally worked? We scoured the old place and moved. Even then some came with us that were living inside of the couch. The only thing that killed them was a combination of hormone based traps, killing them on sight and cornmeal spiked with boric acid.
My grandmother (Pakistani) taught my mummy a trick- we were living in Lagos, Nigeria and we had taken tons of basmati rice with us. We got weevils in them. My grandmum said that we should put sheets in our garden and spread the rice over them in the sun for a few hours. It was the only way we could save the rice. So the weevils were dead and in the rice, but all you had to do was wash them out, they usually flow to the top when youre washing them. It sounds gross, but it was the only way to salvage the basmati and still be able to eat it. xx
I don't know about this particular type of grain weevil (which auto correct wants to change to "devil," btw), but we had a TERRIBLE grain moth infestation (the wheat colored little dudes with wings), that very quickly became out of control. Before we knew what happened, every food item not in the fridge was infested, even many spices! For these types of grain pests, you actually can't even use heavy plastic. They had found their way in to plastic bins and containers. They were even living inside the clean blender, maybe because there was some molecules of fruit in the bottom. Gross! And this all came to light a mere two days after we noticed the first one flying around the kitchen, and absentmindedly thought, "Where did that little devil come from?" The only thing that keeps these guys out are glass vessels with metal lids. Luckily mason jars are cheap and look good on a shelf.
Ps: sure, there's no need to freak about a few bugs you can wash out of your grains...but when they are leaving eggs, webbing, and carcasses through every food item in your pantry, and flapping around your cabinets by the hundreds, the problem is pretty hard to ignore. In fact, I actually started crying when I tried to relieve my roommate from the job of spraying bleach in the cabinet corners...I became irrationally afraid of putting my head in to the dark cabinet, which had webbing hanging in the corners. I know, this makes us sound like we lived in a nasty, dirty house. But it happened really quickly and was easy to miss until the problem was out of control. Let this be a cautionary tale!
I only remember having weevils once when I was a kid. I remember we were making biscuits and my aunt said "Ew! Weevils we can't make this" and threw out the flour. I remember them looking like little tiny worms. 0_0 I had no idea they turn into bugs.
I am super paranoid now because every time I buy polenta or cornmeal I always end up with a few guests already inside the bag. My solution was to stop buying grains from that particular grocery store. I mean, I really don't know what to do and I buy other grains by that maker at other places in town with no problems, so it's gotta be the store. I haven't seem them in anything else and I have been checking every weekly for months.
After reading a post here about pantry moths maybe two years ago, every grain, flour, etc. I buy goes straight into the freezer for a few days to a week before using. Never had a problem since.
My wife and I are currently fighting a battle with these little buggers. They came with a largish bag of brown rice that we didn't immediately dig into. Now I know some ways to kill the buggers or keep them dormant until we can use the whole bag. Thank you!
We had an awful infestation for a while, but now freeze everything until we forget about it after we buy. (Usually a week or two).
My favorite time, though, is when I was growing up and on Thanksgiving was making our mushroom-barley pilaf (family tradition) and the dead weevils started floating to the top. Scooped them off, and no one ever knew:-)
This morning I ate some cereal, Honey Bunches of Oats to be exact, but I also obliviously ate weevils too! They have infested the bag of cereal, and as I later found out everything in my pantry! I don't how I didn't notice them in my cereal, maybe because they seemed to camouflage with it, but its disgusting to know that there are dead weevils in me! o_0 eew!
It's not whole grains but last year I had a terrible infestation from raw (supposedly fresh) walnuts. I had a plastic bag full of it and didn't eat them right away. Then I had to move and I must have tossed the bag in a box. It took a couple of months or so to get to unpack the box and until then, I started seeing moths flying around the apartment. I immediately suspected the spices but they were all fine. Good thing months are kind of dumb and easy to kill but it took a few months to get rid of them all. Every once in a while I'd open a drawer from the room and still find a dead egg or two....
Now my raw walnuts are in the freezer, much to the displeasure of my boyfriend and his frozen foods/pizzas.
Put all grains newly purchased in the freezer before putting them in the cupboard. Also I used Aunt Norma's pantry moth spray and it worked like crazy... those little buggers hate the smell and it kills eggs and larvae (eww!) in the corners and hard to reach places. I have never had a problem again after using this spray!!!
I have kitchen cabinets that are made of that cheap glued together pasteboard crap, and I think the weevils in my apartment are living on the glue. I have cleaned until my fingers bleed, and it has been literally years since any grain has seen the outside of my fridge, and it doesn't matter. I can;t get rid of the things, and now they are all over my house.
When I realized that the tiny black bugs I've been finding in my house are grain weevils, I checked the bag of birdseed I'd bought months before, which turned out to be massively infested. I have two other separate closed containers of the same seed. One is for squirrels, which was also infested. The other is for birds and I had been adding cayenne pepper into it to keep squirrels away. Interestingly enough, apparently it keeps the weevils away too. It contained had No weevils!... From now on, I'm putting my bird seed in the freezer for a week just to make sure.
This will take care of your weevil problem and it totally safe as a food grade item.http://www.ebay.com/itm/FOOD-GRADE-DIATOMACEOUS-EARTH-10lb-Kills-Bed-Bugs-Fleas-Insects-Roaches-/251017658046#vi-content