Out botanizing today John and George saw ailing Red Bay (Persea borbonia) trees, probably thanks to Laurel Wilt Disease. The victims had characteristic black staining in the young wood, and I thought I saw galleries in a freshly sawed fallen trunk. Whether or not my Dr. Oz diagnosis is any good is no biggie, because the important—or at least odd—thing is an approaching parallel disaster. Most of this week I’ve been in southeastern Michigan, my botanical homeland, and the epicenter of yet another U.S. tree calamity headed our way, the Emerald Ash Borer. The first U.S. Emerald Ash Borer and the first U.S. Laurel Wilt Disease both date to 2002. (And for the hat trick, the Oriental Fruit Fly made its U.S. continental debut in Florida likewise in 2002.)
Both diseases spread southward from more northern origins:
- The Emerald Ash Borer first turned up near Detroit. (It had probably been around awhile.)
- Laurel Wilt first appeared in Georgia.
Asian beetles are to blame for both:
- The Redbay Ambrosia Beetle drills fungus-lined galleries into red bay wood.
- The Emerald Ash Borer destroys the inner bark and youngest ash wood.
Both beetles were probably stowaways in wooden pallets or other wooden shipping materials. (So was the Asian Longhorned Beetle, another pest on ash, maples, and more.)
Both beetles have broadened the attack to species beyond the initial hosts.
This week botanizing around Toledo, Ohio, and Adrian, Hillsdale, Ann Arbor, and Jackson, Michigan was a thrill in wild flowers, native orchids, grasses and sedges, and butterflies, but….all silver linings have their dark cloud, and not just the mosquitoes. The area looks in places like Florida after a hurricane but the Michigan hurricane selected ash trees. As the decaying bark falls away, the Emerald Ash Borer galleries suggest ancient scripts…spelling doom. Ash seedlings come up, but who knows how they will fare?
So why fret in Florida? Since 2002 the EAB has sprinted across most of the Midwest into Canada, some western states, New England, and as far south as central Georgia. Here it comes. Does a warm climate protect us? Probably not much, as the beetles live in even hotter Asian locales.
The USDA lists parts of Palm Beach County along with most of Florida as at risk. Does the fact that White Ash has a limited Florida distribution protect us? Not so much: the EAB reportedly can get into any species of ash. We have three in the sunshine state, including in our immediate area, even in my back yard. And to add angst, the bugs have broadened the attack to fringetree (Chionanthus virginicus). Florida has that species plus the endangered endemic pygmy fringe tree (C. pygmaeus), and several more members of the Olive Family, including the ubiquitous Swamp Privets (Forestiera species).
Sure do hope that nobody reading or writing this post spots the first Emerald Ash Borer in Florida.
Note: Forgive me for using the same post in both of my blogs.