All in all, I thought this was a pretty darn good foliage season. The reds were especially good up here and there were no storms to knock the leaves off early. At Tuckaway, leaves seemed to fall overnight on the 15th of October and our road became a golden carpet.
But, like last year, there was a lot of premature browning of the Sugar Maples. Part of that was due to the Maple Trumpet Skeletonizer that was discussed last month in Splendid Splinters. However, the majority of browning was caused by the Maple Leaf Cutter (Paraclemsia acerifoliella (Fitch)). The Cutter is widely distributed over southern Canada and the northeastern U.S. and prefers Sugar and Red Maples. Beech and Birch that grow nearby can also be affected.
The adult moth is blue and emerges in late May. It lays its eggs in mini slits on the undersides of the leaves and the newly hatched larva "mines" the leaves for about two weeks. It then cuts two oval pieces of leaf and sandwiches itself between them to form a protective home. From there it reaches out to eat the surface of the leaf in all directions.
When done, it picks up its "home" leaving a green oval area where the home was. It then drags its little shelter to another part of the leaf and starts over. The end result is a leaf with a bunch of brown circular areas that can become holes.
The larva is dull white with a brownish head and thorax. It crawls or drops to the ground in September to pupate. Like the Skeletonizer, the damage done is usually more visual than lethal. However, populations in small areas can become abundant and if damage occurs several years in a row, older or already at risk trees may be severly weakened or even killed.