Pine needle scale crawlers are present in northern Illinois. Scout for the brick red crawlers on the needles and stems. Application should still be effective in southern and central Illinois, as well as northern Illinois. Spray with acephate (Orthene), bifenthrin (Onyx, Talstar), cyfluthrin (Tempo), insecticidal soap, or summer oil.
Euonymus scale crawlers are lemon yellow and should be present in southern and central Illinois. Spray with the same insecticides as recommended above for pine needle scale crawlers.
Maple petiole borer has been found in northern Illinois. This sawfly tunnels as a larva in the petioles of maple leaves, severing the petiole, and causing leaf drop. Dropped leaves have just a short portion of the petiole still attached to them. This allows one to distinguish from physiological leaf drop due to heat and drought, as those leaves have complete petioles attached. Because maple petiole borer does not seriously harm the tree, no control is recommended. The sawfly larva remains in the portion of the petiole that remains attached to the tree, so raking up and destroying the fallen leaves has no effect on the borer. (Phil Nixon and Morton Arboretum)