Paul H. solved his own tree mystery. I’ll allow his words to tell the tale:
“In August I sent you an e-mail concerning a problem I was experiencing with my Yoshino cherry trees. As I explained, the bark was being chewed off up high in the tree – sometimes removing the bark completely around the limb and thus killing that limb. I went on to explain that definite teeth marks gave rise to suspecting some sort of rodent – perhaps a rat! After spotting a pair of rats, which had taken over the occupancy of a bird house in my garden, I was almost certain this was the source of the problem. Given that the chewing problem occurred only at night I became certain that it was a nocturnal creature of some sort.
“My county Extension agent thought it might be a beetle that lives in the soil and chews bark like a beaver. I treated my three trees with insecticide as he directed but continued to see the damage.
“Well, I have captured our culprit in a trap! It was indeed a rat, a roof rat. After the demise of this critter I obtained some rat bait. Using masking tape, I taped a bag of bait to a limb about six feet up in each of the trees. The next morning each bag had been chewed into and the bait eaten.
“Now the bark is no longer being chewed off my trees! I have since taped new bags in those trees and they have remained intact. MYSTERY SOLVED!”
Garden mysteries such as these are sometimes never resolved. The damage is observed, theories are conjectured but the ultimate cause is never discovered. Paul and I are lucky we sleuthed out the miscreants so we have a resolution to our tales of tree woe!