Apparently, these little pests - just one to two millimetres in length - are attracted to white and yellows. Unfortunately, those are the most popular colour choices for picture mounts.
These are what you’d call super pests. You never get one of them because they travel in swarms. There’s nothing in the frame for them to damage. They just find the tiniest gap in the frame, crawl in, suffocate and die.
By the time you notice it, there’s likely about a hundred of the little tiny black speckles all over your mount, most often at the bottom of the frame.
They don’t bite humans. They don’t breed and they don’t do anything to the frame to damage it, other than make it look really bad.
When thrips are most active
Thrips are also known as thunder flies and you’re best to remember them as that name. Because it’s usually when the weather takes a thundery storm that swarms of these tiny insects escape indoors; although they do prefer garden plants, and greenhouses but often by accident they land indoors and make their way to somewhere warm, cosy, and white or yellow. Then they settle, suffocate and die.
How do they get in when the frame’s supposed to protect your prints?
No matter how careful you are, there’s always going to be a tiny bit of leeway in the frame where insects will crawl through. Mostly it’s on old picture frames with damaged taping around the back edging of the frame.
When you’re putting frames into storage, such as in the attic, you’re best to ensure there’s superior quality masking tape, or even duct tape around it, perhaps sealed with newspaper first to prevent the tape contacting the frame.
The risk of damage by thunder flies
When you don’t know what these things are and only know you’ve these ugly looking black things all over the inside of your picture frame, it can leave you worried about opening it, touching them, inspecting for damage and so on…
They don’t damage any material, frame, mount board or a wooden frame. They only affect its appearance.
There’s only three things you need to do to get rid of thrips and you don’t need a professional to do it either.
Take the picture out of the frame and use blasts of air, such as from an air gun or hose to spray them away from the mount board or the picture or painting they’re on. You don’t need chemicals for this because you are only removing the body of the insects, and not any larvae left behind.
There’s none of that.
When the insect bodies are gone, you won’t even know they were there. However, you may as well take the opportunity to dust the print down while you have it off the wall and cleaning it anyway.
Cleaning picture frames that are affected by thunder flies
- Step 1: Use air to blow the insects off the print or mount
- Step 2: Inspect the frame for any gaps and worn out sealer tape
If the sealer tape is ripped or not tight enough replace it with quality sticky tape to get a tight fit between the backing board and the frame. We’ve heard that blue traps are ideal for monitoring thrips however, since they aren’t going to damage your prints, nor are they that common, you likely won’t need to go to too much hassle.
- Step 3: Put the frame back together when it’s insect free
That’s all there is to it. Take the frame apart, the picture or print out of the frame, blow the insects away from it (preferably outdoors) give it all a dust while you’ve got the frame apart, and then go ahead and put it right back together.
Do thrips come back?
They may do, they may not. They’re weather dependent and only really active for a couple of weeks out the year. The most active time of year is the hottest weather. Whenever it’s hot, with high humidity levels, these swarms will be looking for shelter.
When they can’t find that outdoors, they’ll make their way indoors. Similar to what midges do if you leave a window open during the summer and the room light on.
Just as midges are attracted to light, thunder flies are attracted to white.
Disassemble the frame, air blow them off it, for which a hair dryer on the coolest setting will do the trick, dust down the rest of the picture, give the frame a clean when you’re at it, and then put it back together again.
That’s all there is to getting rid of thrips from inside your picture and again… don’t worry about them. They don’t do any harm, and it doesn’t mean your home is a breeding ground for insects.