Willow Trees Are Spitting Down Sap

Question From: r. james - Belmont, North Carolina, United States
Q: OUR TORTUED ( CORKSCREW) WILLOWS HAVE BEEN IN FOR AROUND 15 - 20 YEARS AND THIS year they have started to exude tremendoub amounts of sap -you can stand under them and can feel the sap spitting down - i am loathe to remove the trees but the sap is becoming a real issue...i can see no obvious insect infestation

A: I'm pretty sure your trees have aphids. They give off honey dew which drips like sap when the infestation is bad. Best And Happy Yardening, Nancy