We had a problem with too many bees, yellow jackets, wasp near willow trees and were advised by Lone Oak Aborist Services that the reason is an aphid infestation: aphids secret honeydew which bees etc. like. The remedy suggested was to spray against aphids. They did spray for ca. 5 minutes, couldn't reach the top of the tall trees with their jet, and the next days we had even more bees, yellow jackets swarming! They charged for this "service" $250.00. I stopped the payment after we discovered the misinformation we had received and observing the results. I strongly recommends against this type of "services"! Unhappy customer Huntington, NY