Posting this to IMHO as I am not sure there is a clear scientific answer, but I would appreciate any technical insight if it exists.
For years now my wife and I have been battling with bugs (maggots and small moths) that miraculously appear in pretty much all of our foodgrains after some time. We have tried a range of containers, most recently this one from Ikea, but the little buggers always seem to get in there. And it isn’t just one of the grain types, it’s pretty much all of them. If it is relevant, we keep basmati rice, regular white rice, white flour, whole wheat flour, oatmeal, polenta, corn meal, Bhutanese red rice and chick pea flour. Originally we suspected that the moths might be coming from the ones that were imported from South Asia (my Indian MIL thinks that the Indian grains often have eggs in them), but keeping the grains in the Ikea containers did not stop the others from getting the moths too. And after one time when a batch of the red rice was totally overrun with the moths, we baked the next batch in the oven to kill any eggs, but it still got infested.
We are getting really sick of having to throw out the grains frequently and/or not being able to depend on having something when we need it. And to add to the fun, my 4 yo daughter is terrified of the little moths when they get out and fly around the apartment.
Do other Dopers face the same problem, and do you have any advice for how to deal with it?
We found rice weevils in a bag of rice once. We’ve since learned that it’s advisable to put a new bag of rice in the freezer for a few days to kill any weevils/eggs that might already be present, and then store it in an airtight plastic container to prevent re-infestation. Haven’t seen any problems since we started doing that.
Don’t know about your other grains, but you might try freezing rice for a few days when it arrives at your home.
How hot did you bake it? The Wikipedia page says >140F should do the trick.
Throw away all grains and cereals (and probably pasta and dry beans, and anything in a box) in your cupboards. Take everything else out of the cupboards, and clean them thoroughly. I know that 409 spray does a job on ants (they’d get on the kitchen counter when I lived in L.A.), so I suspect it would do well with other insects. Or maybe use vinegar. Pay special attention to the joints and cracks. Vacuuming after the cleaner dries might be overdoing it, but it couldn’t hurt. (I’d clean again after using a vacuum.) Clean everything that’s going back into the cupboards before you put them in. If there are bugs in your grain, it’s not unlikely there are bugs and/or eggs elsewhere.
Buy cereals and grains in smaller amounts, which can be consumed in a reasonable amount of time. Store them in containers like the one you pictured. I’ve heard that weevils can chew through zip-top bags.
I guess I will have to do a major cleanout as described. But I am just wondering about how they ended up in all the containers. Does this mean that each of my grains were independently infested when I bought them? Doesn’t seem likely. It seems more likely that the moths traveled from one contaminated container to the others. But I would have thought the Ikea containers would have done the trick.
The only thing I can think of is perhaps the lids were not as tight as I had hoped. They seem to be airtight when they are shut, but there isn’t much resistance when I open them, so perhaps they open accidentally? I think I need to get containers with a latch and rubber gasket…
Buy smaller quantities and/or store these products in the freezer. It sounds like you are keeping your flours and grains lying around for too long.
I used to get bugs in my flours and grains when I’d make overly ambitious shopping trips and buy a lot of stuff, then get busy and not use it up quickly. It doesn’t happen any more, because I’ve learned not to leave products like that lying around. If you can’t use it up in two or three weeks at most, and you don’t have freezer space for it, don’t buy it.
freezing will kill the non-egg forms of the bugger. then let it warm and let any eggs hatch, refreeze before any adults emerge and lay new eggs. repeat until you see no more live things. do this by observation (use a magnifier) and knowing the life cycle of what the bug(s) might be.
do for each item. keep in tight plastic or glass containers. they can make their way through paper or plastic bags (they will chew their way out of a ziplock bag).
I have a few OXO Good Grips storage containers. I didn’t buy the linked set; I just get them as I need them. I have the four-quart containers for flour, sugar, coffee, and oats. The buttons on the top push flush with the lid, and create an airtight seal.
I can’t say whether they work to keep bugs out, as I haven’t had bugs. I keep my rice, beans, and pasta in bags in the cupboard. But the containers should work since a seal is created. And they’re convenient.
I took the scorched earth approach a few years ago. I had been having problems with what I think were carpet beetles but they were in the flour, crackers, etc. Eventually, I just tossed EVERYTHING that they were in or that they might get into. Pasta, crackers, flour, cereal etc. Cleaned out the pantry and the cabinets and now I keep everything in some kind of container. Pasta in tupperware type containers of some kind. Flour in freezer bags (even before it’s opened) and I keep an eye on everything all the time. It was another week or two before the rest of the bugs disappeared, but eventually they were all gone.
About two years later I started finding them again, but I traced them back to a big bowl full of candy (hershey bars, kit kats etc). Dumped the whole thing (which were all chewed up by the bugs), washed it, took out the garbage and haven’t seen anymore since.
At this point I figure there’s probably always going to be a few in the house and since they don’t hurt people and aren’t wrecking fabrics it’s just a matter of keeping them at bay. As soon as I see one, I find the source and deal with it. But as long as I keep everything sealed up, I seem to be in good shape.
But if you have an infestation, the easiest thing to do is to just throw away every single open thing you have. Actually, I found that with the beetles that I had, they would even gnaw right through closed pasta/cracker bags to get in. I just threw out everything. Why start buying new stuff when there’s still bugs in the house. Scorched Earth. Don’t throw good money after bad.
Pantry moths are really hard to get rid of. I’ve had them a couple times and each time, I’ve had to do the scorched earth methodology that Johnny L.A. and Joey P describe. You just have to throw out EVERYTHING.
The worst time was when they got in some birdseed I had in my attached garage. I thoroughly cleaned and threw out every possible thing they could get into in my kitchen two or three times, and they kept coming back. It was only months later when I decided to refill my much-neglected bird feeders and I opened the big container of birdseed in my garage and found it teeming with moths did I realize where they were coming from. For whatever reason, they didn’t seem to hang out in the garage so I never noticed them there. They must have hatched and made a beeline for the pantry.
I think they’re right. Dump everything potentially infested, scrub everything down with hot water, chemicals, and abrasion. Trash any containers that may not seal airtight. Buy only single-serving packages of food, then buy one bulk ingredient, freeze it on entry, then right into a sealed container. Leave for a while, watch for hatching, freeze again as needed. Gradually reintroduce more bulk ingredients.
We had them when I was a kid. Here’s the Wiki page on them. (fun fact: you need to freeze stuff for a whole week to get rid of them! hardy little buggers.) I have occasionally seen pantry moths on new packages from the organic store. You can tell if you shake the grains in the plastc bag and you see some of the grains webbed together and held to the plastic by silk thread.
I still sometimes see the grains clinging to the plastic of the bag of container, but when I look closer it is just static cling, fortunately.
As stated previously, it is possible that bugs/eggs were in the grains when you purchased them. If not, the insects are common and could easily have gotten in there after you got it home.
It is difficult to seal tightly enough to keep them out - you would be amazed at what they can get in to.
As a routine, I freeze store dried grains, rice, beans and peas when I buy them and then store them in the refridgerator as a matter of course.
I have also noted (anecdotally - NOT DATA) that often you’ll find them in one specific bag and for whatever reason not in others. We one had a major issue and I finally found a small bag of mixed dried beans in the back of the pantry that was teaming with larvae - once I threw that out the problems stopped. Of course this may not (likely not) be true in all/most cases).
Seriously though, freeze it first then keep that stuff in the fridge.
Also, eating the larvae won’t hurt you in the least, they’re nutritious actually.
But it’s kinda gross and sort of embarrassing when you have friends over and your making dinner and one of them says ‘what’s that’ and you say 'meh, just some bugs, pick around them" which I had to do once or twice.
I had them years ago. They were impossible to get rid of. We were only successful when we gutted the kitchen down to the studs during our remodel. The trouble is that they’re prolific as bunnies and the larvae can crawl into the tiny crevices. I’m talking behind and under shelves, and in the crack between the door and the molding. When I stripped off the wallpaper border, some of them had crawled behind it.
So, yeah, my advice is to gut and remodel your kitchen.
