Weevil \ Saw tooth grain beetle infestation. Anyone ever experienced this?

[krazydave]

So, this is mostly my fault, but I had a sack of grain that I knew had some bugs in it. I separated that sack from the rest of my stored grain so that I could finish fermenting some stuff in my chest freezer and throw the sack in there for a few days to kill them off. I've done that previously and it worked like a charm.

However, due to being busy, days turned to weeks which turned to months and through the summer heat in my garage, that sack basically exploded with what I've now identified as saw toothed grain beetles. I've found them inside my kegerator where it appears the cold in there has killed them, they were in my chest freezer, they made it across the garage and I found a few of them on my other sacks of grain. I have about 15 buckets of various grain stored also, but as of now, they all seem bug-free.

The affected sacks of grain have now been in the freezer for about a week, but I'm still finding the bugs throughout my garage. What concerns me, is that I'm also starting to find them in my house near the entry door, but so far they seem to be staying right there.
I definitely do not want these little pests making it to my pantry and making a mess out of that!

Last week I tried using a fogger in the garage overnight that listed rice weevils as one of the pests that it killed. It, however, didn't affect the beetles.

I did see a fogger that's meant for bed bugs, that specifically lists "grain weevils" which I'm considering trying next.
But has anyone here had a problem like this and know what definitely works to kill them all off?

Trying to avoid calling the Orkin man, if I can.

 

[grampamark]

Short answer-call the Orkin man.

I'm a farmer. We raise various cereal crops, including wheat and barley. Keeping bugs out of stored grain is just one of the many things we have to deal with.

We use a product called Phostoxin to kill bugs if we do get an infestation. The problem with using it is that it is highly toxic to humans and requires a license to purchase and apply what are classified as "restricted use pesticides". The stuff is basically mothballs infused with phosgene gas. Even brief exposure to the vapors can cause respiratory irritation; prolonged exposure can kill you.

The fogger you referenced is worth a try. If that doesn't work you should probably call in a pro.

Mark

 

[IslandLizard]

How about putting out some bait (grain, flour may work) to attract, then eradicate them. Poison would be my last choice, it may render your stored grain useless.

I had a small but contained weevil infestation in a few paper bags with raw grain kernels I bought at Whole Foods. They were about to crawl out of the storage tote looking for a better venue because they couldn't get inside the plastic zipper bags also stored in there. My dog actually heard them a week or 2 before and alerted me, but I ignored his curiosity until I opened that tote on brew day...

Anyway, those paper bags were rustling and crawling from weevils. 100s. I simply drowned them in a large bucket with water. Poor buggers.

 

[krazydave]

How about putting out some bait (grain, flour may work) to attract, then eradicate them. Poison would be my last choice, it may render your stored grain useless.

I had a small but contained weevil infestation in a few paper bags with raw grain kernels I bought at Whole Foods. They were about to crawl out of the storage tote looking for a better venue because they couldn't get inside the plastic zipper bags also stored in there. My dog actually heard them a week or 2 before and alerted me, but I ignored his curiosity until I opened that tote on brew day...

Anyway, those paper bags were rustling and crawling from weevils. 100s. I simply drowned them in a large bucket with water. Poor buggers.

I think the problem is that because my garage is about one half brewing equipment at this point, they are able to find enough flour or random grain bits that they still stay pretty widespread.

The remainder of stored grain I have is all in sealed containers, so poison shouldn't spoil it.

So going on what grampamark said, I think I'm going to try the bed bug fogger first and see how that does. And if that doesn't work, I'll have to just suck it up and get the Orkin man out.

Thanks!

 

[lump42]

Foggers are mostly ineffective. I would avoid them.
Source:https://entomology.ca.uky.edu/ef643

To keep them out of the pantry, keep stored food products in hard plastic air-tight containers, or zipock-style bags. Freezing for four days or heating to 130 for 30 min will kill them as well. The first step is to remove any infested items (not just grain, but also pet food, bird seed, flour, prescriptions) or treat to kill anything that is infested. Then clean the entire area thoroughly.

You should also invest in large air-tight containers for the sacks of grain. Vittle vaults are a popular brand. Helps prevent and infestations and keeps any contained.

Here is a pub from Univ of Missouri on dealing with stored food pests in the home. Prevention and eradication are at the end.
http://extension.missouri.edu/p/g7370

 

[IslandLizard]

I think the problem is that because my garage is about one half brewing equipment at this point, they are able to find enough flour or random grain bits that they still stay pretty widespread.

The remainder of stored grain I have is all in sealed containers, so poison shouldn't spoil it.

So going on what grampamark said, I think I'm going to try the bed bug fogger first and see how that does. And if that doesn't work, I'll have to just suck it up and get the Orkin man out.

Thanks!

When you see them trying to find different areas, they're out of food. They lay their eggs inside the kernels (after boring a perfectly round hole in one end). Keep your grain stockpile sealed (as you have been), and prevent them from laying new eggs that can hatch. They'll die out after a few weeks.

Foggers are bug specific, aren't they. Not sure a bed bug fogger will do them in. Maybe it will, interrupting a certain metabolic or reproductive cycle. A garage is airy, and the vapor needs to penetrate areas to kill them. Seal all cracks, like around the threshold and sides.

 

[lump42]

When you see them trying to find different areas, they're out of food. They lay their eggs inside the kernels (after boring a perfectly round hole in one end). Keep your grain stockpile sealed (as you have been), and prevent them from laying new eggs that can hatch. They'll die out after a few weeks.

Foggers are bug specific, aren't they. Not sure a bed bug fogger will do them in. Maybe it will, interrupting a certain metabolic or reproductive cycle. A garage is airy, and the vapor needs to penetrate areas to kill them. Seal all cracks, like around the threshold and sides.

Most foggers contain a general insecticide in the pyrethroid type insecticides that target a wide range of insects. Foggers won't get the insecticide into the cracks, crevices, and other hiding spaces. They just leave a film of insecticide on horizontal surfaces. Better results will come from move everything out and cleaning first. Insecticides should not be relied on sole for any pest control situation. Targeted sprays around the grain storage area will have more effect after the area is clean. There is no quick and easy way to deal with them.

 

[krazydave]

According to that missouri.edu link that lump42 just shared, it states this:
"The most commonly used insecticides for this purpose are pyrethroids (active ingredient ending in -thrin). Common pyrethroid active ingredients include pyrethrin, cyfluthrin and cyhalothrin."

The bed bug fogger does have pyrethrin as its active ingredient, but it does also seem that they aren't very effective.
They also have an aerosol spray that has lmiprothrin and cyhalothrin that I can buy and use to spray in the cracks and crevices that I'm finding them in or around.

Also, from my research, I've read that the life cycle of the adults is an average of 6-10 months, and even up to 3 years in some cases.

If I didn't have so much stuff in my garage, I would likely pull it all out and clean it. However, my garage contains likely enough tools and equipment that I'd have to spend days doing so.

 

[krazydave]

BTW, all of the infected grain should be good now as it's been in the freezer at -20F for a week, and I am going to be buying some more sealed containers for it today so I can get it out of the freezer and keep any living bugs from attacking it all over again.

 

[Trail]

BTW, all of the infected grain should be good now as it's been in the freezer at -20F for a week, and I am going to be buying some more sealed containers for it today so I can get it out of the freezer and keep any living bugs from attacking it all over again.

"Should be good now" as in... you're going to mash some grain with a bunch of dead bugs in it?

Nope. Noping right the hell out. Remind me never to drink a beer at your place.

 

[krazydave]

"Should be good now" as in... you're going to mash some grain with a bunch of dead bugs in it?

Nope. Noping right the hell out. Remind me never to drink a beer at your place.

Probably not the one that was the source of this infestation (that's a little too much insect matter for me, even), but the remainder of my base malt, yes.
It happens a lot more than you think and I can guarantee you that you've already drunk plenty of beer that was mashed with bugs.
It's not like they're going to make it through the whole mash and boil and end up as a solid bug in the final product, after all.

Maybe I'll just brew a really big beer and call it "Weevil Dead"

 

[GPP33]

"Should be good now" as in... you're going to mash some grain with a bunch of dead bugs in it?

Nope. Noping right the hell out. Remind me never to drink a beer at your place.

That was my thought as well. When the first infestation was noticed it should have gone in the trash, the whole thing. Killing em and leaving them in the grain, nope.

Check out the ziplock storage totes. Cheap and air tight.

 

[krazydave]

Just a follow up on this for anyone who may encounter issues with these pests.

I sealed all of my clean grain up and bombed my garage with two bed bug foggers and sprayed the perimeter and connecting hallway to my house with a bed bug spray.
Then after three days, I moved most of the stuff in my garage to clean up any dead and check for any survivors.
For the most part, it did the trick as the infestation has been knocked WAY down to the point of them not existing anymore.

It’s been over a month now and I’ve only seen a couple living in the hallway of my house, but other than that, it seems I’ve managed to eliminate them.

On another note, it also killed off the spider population in my garage and I haven’t had to deal with them anymore either.
Kinda makes me wonder why I didn’t fog the garage a long time ago!

 

[IslandLizard]

[...] On another note, it also killed off the spider population in my garage [...]

Pour spiders... :weep:

 

[MaryB]

I spread diatomaceous earth around doorways, window sills, the foundation... it doesn't kill immediately but it a good long term pesticide that will keep them from coming back. And it is 100% human safe, you can eat it!

I heat with a corn/pellet stove so I have ~ 100 bushels of corn in storage all summer. I covered the top of it with DE, raked that in, then added another heavy dusting. This is in an unsealed storage building and zero bugs! But I do it anytime I have to store corn over summer.