Question
Hi Jim, I live in Muskoka Ont. This year in July we had a sticky covering on deciduous trees especially maples. What could this be?

Answer
This sticky is called honeydew. Honeydew is excreted by an insect called an aphid. These soft bodied insects suck the plant juices from the plant and excretes the honeydew. The aphids will need to be controlled before the dripping will stop. The foliage will need to be sprayed but this may not be possible with large trees. a systemic insecticide can be used as a soil drench--the roots will absorb the insecticide and transport it to the leaves and twigs and when the aphid suck the juice they will be killed.

Sprays recommended are: Contact Insecticides Numerous contact insecticides are registered for aphid control. Since aphids are often placed under considerable pesticide pressure in field crops and greenhouses, they may be resistant to certain categories of insecticides. Therefore, if you do not obtain reasonable control, consider rotation to another insecticide. Contact insecticides currently registered for aphid control include: acephate (Orthene),  bifenthrin (Talstar), chlorpyrifos (Dursban),  diazinon,  malathion, nicotine sulfate, pyrethrum,  rotenone, resmethrin, and tetramethrin + sumithrin.

The soil drench is Imidacloprid (Bayer Advanced Garden Tree and Shrub Insect Control) is a newly available systemic insecticide that can provide aphid control on trees for several months following application to the soil.