Clean up Debris to Reduce Skeletonizer Populations

Q. Although I was able to control the grape leaf skeletonizer all summer, I came back from a three week trip with 99% of the leaves stripped and dried up.  The grapes were picked in August and September. Should I still treat the vines with BT or just forget it since it is October and the leaves

would have soon turned brown anyway?

Skeletonizer feeding on the bottom side of grape leaves.

A. I would just let it go at this point. The only thing I worry about a little bit is regrowth (new leaves produced) because the temperatures are still warm. Regrowth will drain stored food reserves from inside the plant.

            These reserves are used for next year’s production but there should be plenty of “food” left even if it regrows this fall. I would not worry about it if that happens.

            Make sure you cleanup the leaves at the base of the plants. This is where the pupal stage (cocoon) will overwinter and if you do not cleanup this debris the attack on the plants next year will be earlier and more intense. The adults are winged moths so they will move from neighbor’s vines to neighbor’s vines.