Usually, when we talk about conservation and preservation, it's in the context of a natural balance - an equilibrium among life forms. But when that balance is disrupted, conservation of one creature may mean trying to stamp out another. Maryland just placed about half the state – all of the counties west of the Chesapeake Bay – under quarantine. Wood quarantine that is, because of an invasive pest. The Emerald Ash Borer has already killed tens of millions of trees nationwide, and now it's in Maryland and Virginia.