Have you ever heard that question, while showing property?  If so, chances are good that you didn't know the answer.

That purple thing, my friends, is a trap for Emerald Ash Borer.  Which leads to the next question... what's an Emerald Ash Borer? (And tell me again, why do I care?)

Emerald Ash Borer is an exotic beetle from Asia that attacks ash trees. It has killed many millions of ash trees in Maryland, Michigan, Indiana and Ohio, and recently it's been found in Virginia, West Virginia and other states.

This invasive species of insect was the topic of a horticulture presentation made at my garden club meeting last week by Dick Bean, an Entomologist with the Maryland Department of Agriculture. 

I'll be the first to admit that lectures are not my favorite programs... I much prefer flower arranging workshops and field trips to interesting places (like the one to Mount Vernon in June).  BUT I always learn something when an expert like Dick speaks at one of our monthly meetings, and this was no exception.  In fact, I was glad to learn about these traps in case a client does ask me about them someday, because they have been placed by the Maryland Department of Agriculture along roadsides and in neighborhoods in Anne Arundel, Prince George's and Anne Arundel Counties.

These purple traps are three-dimensional triangles or prisms made out of thin, corrugated, purple plastic that has been coated with non-toxic glue on all three sides. They are about 24 inches long and hang vertically in an ash tree or are secured to the trunk of a tree.  The traps are baited with a lure (Manuka oil) to increase the attractiveness of these traps to beetles. They are not toxic, but they are very very sticky.  If you find one on the ground, you should call local authorities (In Maryland, the number is 1-800-342-2507) rather than pick it up yourself.

You can re-assure your prospective buyers that:

1.  These traps will not harm people, pets, or wildlife (BUT the non-toxic glue can be extremely sticky and messy.)

2.  The presence of "that purple thing" does not indicate any tree in the yard, or even the neighborhood, is affected.

Photo at left shows trees that have been affected by the Emerald Ash Borer.

Here's how the trap works (just so you can sound like a know-it-all when your buyer asks):

During adult emergence of these beetles, they fly around ash trees, nibbling on leaves and looking for a mate. If an one lands on a purple trap, it will get stuck in the glue. In the fall, crews will return to trap sites to collect samples and remove the traps.  Any insects collected from the traps will be cleaned and sent to the USDA identifier for verification, which will be communicated to the appropriate State plant regulatory official.

Maryland agents (and their clients) can learn the latest about the spread of this invasive species of insect on the MD Dept. of Agriculture website.  I'm sure there is information on othe state websites, as well.

You just never know what you're going to learn on Activerain, do you?  I'll bet it never occurred to you this morning when you woke up that you'd be learning about purple things hanging in trees.  But you'll be glad you did read this if a client ever says to you "What's that purple thing in the tree?"