Shiny substance on narrow leaf cottonwood trees

Asked August 23, 2019, 11:30 AM EDT

What is the shiny (NOT sticky) substance on some but not all leaves of narrow leaf cottonwood trees along Blue River in SIlverthorne (and probably in other places too)?
Thanks!

Summit County Colorado

1 Response

I believe it is the honeydew from aphids. It isn't always very sticky.