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House Infested with sow bugs

Priscilla writes in, asking...

We moved into a house that was infested with sow bugs.  It is a post and beam house.   When I say we had an infestation, I mean that we were sweeping up dust pan loads of the critturs on a daily basis.  We think we now have them under control - but I wonder if there is a specific poison for such varmits.  My husband used about everything he could find - spraying inside and outside.  We never could find any information about them.

Thanks for any suggestions you might have to make sure we never have them again!


And I wrote her back with....

Hello, Priscilla:

Certainly sounds like you had a lot of sow bugs!

First of all, don't worry about the bugs!  Sow bugs are outside bugs and won't normally survive inside a house.  They need moisture, so they will be wherever you have enough moisture.  Outside, you can find them everywhere.  Turn over a rock, they are there.  Also, they are not dirty, are not vectors or carriers of any disease, they are a nuisance factor only.

You didn't say whether your new house was vacant for a period of time before you moved in, but if it was, this will be part (or most) of the problem.  If it was vacant, hold off doing anything for awhile to see if it ends.  It will end, if this is the case, without using any chemicals.  

Sow bugs like moisture, so make sure that leaf debris (leaves hold moisture and hides the bugs) is cleaned up from around the outside of your house.  Instead of chemicals, use a caulking gun to close any cracks or crevices at or near ground level.  You didn't mention what part of the country you are in, or what kind of foundations (concrete slab, crawl space, basement) your house has.  If your house is on a concrete slab, built more than ten years ago and poured directly on the ground, then this type of construction can have more of a problem with sow bugs or pill bugs.  Houses with basements or crawl spaces tend to absorb these problems before they enter the living spaces.  I don't believe that post and beam construction would be the factor, it depends more on the number of entrance points into the structure, within the first few inches of the outside and, of course, the moisture problem.

Built-in planters (inside) are usually a bad idea for many reasons.  If you have one of these, let me know and I'll go into more detail.

Also make sure all your doors (ground level, to the outside) are weatherstripped.  If your garage is attached or integral with the house, make sure those doors are properly weatherstripped also.  Watch for obvious moisture problems in the garage and bottom level.

Moisture, however, is why these little fellows stick around, so if you can solve that problem, they will disappear on their own.  Sow bugs or pill bugs are not problems that you need an exterminator for, nor are they something you need to use chemicals (inside) for.  Outside is the only place you would use an insecticide - and remember, if you don't solve the moisture problem, the bugs will return no matter what chemicals you use, or how much you use them.

By the same token, if you solve the moisture problem, seal off all the cracks, then you won't need to use the chemicals at all!  Try this way first.  

Your Email address indicates you are in our Great Northeast.  We are in South Jersey, and I can also find sow bugs in our own office basement.  So if the exterminator has them I guess anyone can.

Priscilla, I am going to give you the name of an insecticide to use even though I said that you don't need to use any.  I give you this information only because I don't want you using the WRONG insecticide, if you so decide to use insecticide.  I am not sure what state you are in, but you need to use a granular-type insecticide labeled for use with pill bugs or sow bugs.  Usually the cheapest to use will be diazinon granular at the LOWEST percentage rate, usually "one half G".  This is usually denoted on the label as ".5G" do not use anything stronger.  Don't buy too much, it DOES have a shelf life.  Buy no more than you would use in a summer season and keep it in a dry warm place where it can't be misused by anyone.  Keep it in it's original container and keep your original sales ticket with it.  Best place to buy this product would be in a local garden store.  Make sure it's FRESH!

Apply the granular in the afternoon or early evening by sprinkling lightly (on the ground) around the outside problem areas.  You don't need to do the whole house if they are only on one side.  Sweep or brush any granules off the plants, shrubbery or concrete, this chemical is no good unless it's on the ground.  The rain or dew will help it get to where it has to go.  After 3 or 4 "dews" or a rainfall, it's gone, even though you might still see the "granules."  If you have no rain or dew it can be (lightly) watered in, although at dry times you probably wouldn't need it.  

That's about it.  Hope something here helps you.  And naturally, if there is anything else I can answer, ask away.


Priscilla wrote back with....

I do appreciate your response and want to answer a couple of your

1.  We are on Cape Cod (as our e-mail address suggests).  We have a full basement but we found when making a significant addition, that the walls of the original building did not have full "closure" from the foundation: i.e. - we could see daylight between the supporting walls and the concrete of the basement walls!   We have had that closed with a plastic foam  - so that it is now secure.

2.  We have suspected that the bugs got up in the house  - and bred in the the beams of the post and beam construction.  Moisture probably was a factor as the owners would go to Florida in the winter and while they shut down the house (toilets and pipes drained) there was no heat in the building.

3. I was delighted that you suggested diazinon as that is exactly what my husband ended up using - (plus some other stuff!)

Thank you for your suggestions  - I have given your URL to our three children in St. Louis, Lexington (KY) and Richmond, VA  -  you may hear from them also!


I sent this back....

Hi, Priscilla:

Glad I could help - if I did!  Couple of comments here...

Your #1
That could definitely be the problem.  Closing foundation holes would be a necessity.    If they are actually "holes," I would rather see you do it with (maybe) concrete - something a bit more substantial than plastic foam.  Don't, however, REMOVE the foam to do this.  If you have to replace the foam in the future, do it with concrete, if you can.  You can get a lot of concrete for $5.00!  Cracks can be done with the foam or caulk.  Inspect yearly, in the winter, on a very cold and windy day and you'll be able to find those flaws more readily.

Your #2
It would be unusual for these bugs to actually breed inside.  Although I'm old enough now where I never say "never."  And for them to close up a house, turn off everything such as you describe is false economy.  It would be much better to maintain the environment inside "operational" except for maybe turning down the heat to about 50 degrees.  If you don't maintain the inside of a structure like this, what happens is that moisture accumulates in unexpected areas and can wreak havoc on anything that is moisture sensitive.  Actually, if you were to do it this way, it would be better to leave all the windows open so that the inside would be just as it is on the outside!  Of course, you can't really do this, so the best would be to leave the heat on (low) so there is sufficient air circulation and no moisture build-up.

Your #3
The other "stuff" is a waste - save your money, use as little as possible. (Can you tell that I have some Scots' blood?)

Hope all goes well!


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