I have a line of 10 maple trees planted fairly close together which are shedding some leaves which I have not observed before and the leaves on the trees have a sticky substance on them. Cars parked next to them will have small sticky droplets on them. Must be a bug. Thank you, Paul.
Multnomah County Oregon
The sticky droplets are probably from "honeydew from insects in the trees. Aphids are the most common culprit. They produce sweet honeydew that attracts other insects, especially ants. This is why you see ants in your rose bushes. You can dislodge aphids from the trees with a hose, or use insecticidal soap. Lady beetles are enthusiastic predators of aphids. Cars need to be cleaned, as the honeydew can damage the car's finish. This article has more information: What is this Sticky Substance on My Car? http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=25168.