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Insect in brick mortar #587898

Asked August 10, 2019, 10:55 AM EDT

These pin head size insects are in the mortar of my brick in the front of my house. What are they and how do I get rid of them?

Washington County Minnesota

Expert Response

I'm having a little trouble IDing this insect for you. The first image looks like a moth. I need some clarifying questions -

1. Do you believe that this insect is causing the damage?
2. When did you first notice the damage?
3. It is only happening in one spot? Outdoors or indoors?

I know of no insect that would bore into grout like that. I think a safe first step would be to take a shop vac to the area and clean it up as best as you can. 
An Ask Extension Expert Replied August 13, 2019, 11:37 AM EDT
1) yes 
2) several seasons now. Have had pest control companies out with no results. 
3) yes so far it is contained to a spot outside the garage doors. Outdoors.
I have cleaned up area completely several times. Mortar dust continues to accumulate. 
The Question Asker Replied August 13, 2019, 12:03 PM EDT
I am waiting to hear back from an Entomology professor at the U of MN, I will get back to you as soon as I hear back from him.
An Ask Extension Expert Replied August 15, 2019, 12:28 PM EDT
Thank you!
The Question Asker Replied August 15, 2019, 5:25 PM EDT
Hello,

I heard back from Jeff Hahn in regards to the insect issue. I will paste his response below:
I have had a chance to talk to my colleague. He agrees that insects are not causing this damage, they are not capable of it. He speculates that it is possible that mortar was not mixed properly which could result in it crumbling now.

When I first looked at the pictures of the insects, I identified the first one as a small moth. Looking at it a second time, I realize it is actually a scaly-winged barklouse. This is important because barklice are associated with damp conditions. The second insect picture looked like it could be a springtail which is also associated with a damp environment. It is possible that the area where the problem is occurring is damper and could be contributing to the damage.  

Ultimately, they need a builder to look at the problem and see if they can determine the problem and a solution.

Jeff Hahn
An Ask Extension Expert Replied August 20, 2019, 4:34 PM EDT

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