Saving Ash Trees with Beneficial Insects

Posted by A. Caleb Hartley

 Ash trees are being threatened all over the midwest (starting in Southeastern Michgan in 2002 and spreading to Ohio and other locations in the midwest) by an insect called the Emerald Ash Borer. If you haven’t heard about yet, you most likely don’t live in the Midwest. Consider yourself lucky…

The Emerald Ash Borer, as an adult, feeds on Ash tree foliage - not a big deal. The larvae, however, feed on the inner bark of the trees, which disrupts the ability of the tree to absorb nutrients and water, often killing the tree. This has caused many states to start campaigns advising residents and capers not to move firewood; such as these examples:

Midwest states are actively promoting these campaigns, and are also looking for ways to eliminate the beetle, which originally made it to the US, it is believed, on (or in) wooden crated shipments from Asia.

One of the ways that might be used to eliminate this Ash parasite is to import wasps from Asia.  Eek, you say?  Bringing an invasive species in to take care of another invasive species?  Seems to defeat the purpose… especially with something like a wasp! 

But here’s the kicker - these wasps are not even as large as a poppy seed, and they don’t have any stingers!  The way they can help control the wasps, though, is through their own reproduction - the wasps lay their eggs in the eggs of the Emerald Ash Borer - and the wasp larvae eat the Emeral Ash Borer larvae, stopping them before damage to the Ash trees occurs.

The wasps are only just being tested - about 1,500 wasps were released in Central Michigan.  Hopefully, the wasps will be able to hunt down and kill the Ash Borers and the test will be a success… and that the wasps won’t cause problems of their own!

Namaste,
A. Caleb Hartley

What do you think? Is releasing another foreign insect a good idea to help control the first one, or is it just asking for trouble and new problems? Leave a comment and let us know how you feel about it!