We recently experienced the emergence of the 17-year cicadas. They have left us now but will come again in 17 years. Their egg-laying has affected the trees, leaving orange or brown leaves. But the trees (at least the mature ones) will not be permanently damaged. I was reminded of Handel’s wonderful aria from Serse in which King Xerxes sings of his love for a beautiful plane tree. Trees are sources of oxygen and collectors of carbon dioxide. They are the treasures that may save us from our careless abuse of the planet.