What's that triangular purple box hanging in trees?

It's all about EAB, or Emerald Ash Borer (Agrilus planipennis), a ruthless insect invader from eastern Russia, northern China, Japan, and Korea.  How did it get here?  It's not clearly known, but it is likely that it came in ash wood used for stabilizing cargo in ships or for crating consumer products. 

Recently, an EAB trap was put in an ash tree across the street from our offices at the Old Port park.

EAB is a wood boring beetle first found in SE Michigan nine years ago.  Ever since, it has been detected in southern Prince George's County, Maryland; Indiana, Illinois, Pennsylvania, Virginia, West Virginia, and other states.  EAB is a serious pest to the ash trees as the adult beetles feed on the tree's foliage and the larvae, the most harmful life stage, feed on the inner bark of the trees creating S-shaped tunnels that damage the vascular tissues under the bark.  Of course the ash trees then die. 

The purple boxes you see in many trees throughout the state are traps set in ash trees to attract and catch the beetles.  These traps are set by the Maryland Department of Agriculture (MDA) as part of a national survey for the emerald ash borer.  People should not be worried about these traps and should actually not disturb them since this is part of a major effort to detect this pest and to save our ash trees!  Read more at the EAB website.


Just wondering I live in nort

Just wondering I live in nort east Pa. And I have seen them the other day I noticed that one was on the ground don't know if it was knocked down by people or maybe an animal but I'm tring to find out who to contact about it. ?

Nice to know what there are,

Nice to know what there are, we live in western WI and have been seeing a lot of the boxes.

been seeing theses boxes for

been seeing theses boxes for a long time, glad to know action has been taking place.

I hope this method works,

I hope this method works, it's the first time I hear about these insects and they are not good news. I assume pest control companies in the area have the situation under control, I cannot think about the alternative.

Inside the purple box appear

Inside the purple box appear to be an over sized silica packet hanging in the middle. It is completely hollow on the inside, ill try to take a picture

i understand the purpose of

i understand the purpose of the boxes, but why purple? it is a strange color to see hanging from trees. i wonder if it attracts the beetles?

I think its because the color

I think its because the color purple attracts the betles

I too would like to know

I too would like to know this. why purple?

Purple Boxes

I have noticed these around my home in NY then on a recent trip throughout New England,noticed them also.

Glad to see PA down with the

Glad to see PA down with the Ravens Purple!!!!!! Go Ravens

Purple boxes

Thanks for the info. I have an ash tree and am glad to see somebody is looking for these nasty bugs

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Thank you!

Wow!! Ive been seeing these boxes on my way to work. I live in the Allentown, PA. I figured it had to do something with bugs. Well I'm glad somebody notices these things and cares enough to save our trees! I wanna say a big THANK YOU!!

Purple Boxes

What is inside the box? Anyone know? It would be nice to make a couple myself and hang them in my woods. There's a lot of ash around here and having more traps might be a good idea in this case. Thanks.


I see numerous purple boxes in the upper poconos of PA. I always wondered what they were for.Thnks for clearing that up.

Purple Box

Glad to finally find out what these boxes r for. Also glad to know the Dept. of Agriculture has come up with a "PLAN" to try and stop these tree killing pests!! Your posting of info was very mind settling to many people! Thanks :)

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Purple Boxes

I would like to thank you for clearing this up for me, I was thinking they were bird houses, Ive been seeing them on my way to campground and to/from my family. Hope the DNR can find a way to stop them.

Thank you for clearing up

Thank you for clearing up this for me. I noticed a couple purple boxes in the trees on my drive in Ct./NY. This was very helpful....

Purple Boxes

We live in upstate New York and are also seeing these boxes.  It's nice to know what they're for - thanks!

purple boxes

I live in central Virginia and everyone around the office was wondering what the purple boxes were for. Thanks for helping me get informed!

Ah...the mystery solved.Β  I

Ah...the mystery solved.  I just started seeing them along the eastern part of the PA Turnpike and was wondering.  Thanks.

Thank you for this

Thank you for this information.

I've seen a number of these

I've seen a number of these traps set up here in Western Massachusetts. I first read about the EAB infestation early last year, so I had a guess that these were to combat the beetles. I'll be sure to let my friends and coworkers know what exactly they are. Thanks for your efforts to stop the EAB!


Whoops, my mistake. It was the Asian Longhorn beetle infestation that I read about early in early 2010. That infestation still seems to be spreading like wildfire. Are there any plans of setting up similar traps to stop the Longhorns?

Purple Boxes

Thanks! This was a great debate. We have one at the entrance of our subdivision. We live in Central Kentucky.

ash borer


RE: ash borer

Hey Janice,


I recommend contacting the folks at the Maryland Department of Agriculture (http://www.mda.state.md.us/about_mda/staff_dir/index.php) --or if you don't live in MD, any state agency related to forestry, agriculture or natural resources-- for more information about getting a purple box installed on your property, because I'm pretty sure that is not something you can buy at a store.


Hope this helps.




Jorge Bogantes Montero

AWS Conservation Biologist

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Why are they purple?

Why are they purple?

purple boxes

Thank you for clearing up the mystery of purple boxes in the trees up here in Vermont and for your efforts in battling the EAB.

RE: purple boxes

You are welcome!

Purple boxes

Recently have seen lots of these in our area of Western Kentucky. I finally had to Google them and find out what they were. This was useful, thank you.

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I was suggwsted this website by my cousin. I am not sure whether thiks post is written by him as no onee else know suuch detailed abbout my problem. You are incredible! Thanks!

RE: Purple boxes

You are very welcome!  It really is an important effort to manage one of the worst invaders in the country.

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You're so interesting! I do not think I've read through a single thing like this before. So wonderful to find somebody with a few unique thoughts on this subject matter. Really.. thank you for starting this up. This web site is one thing that is required on the web, someone with some originality!

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