I just noticed my Hackberry tree is being invaded by what I believe to
be mealybugs. The leaves have little fuzzy white spots on them.

f
you look closely, it looks like a light mist of sap(?) is raining down
from the tree. Ants are attracted to this sticky substance. This
happened last season, and it got terribly sticky on the back porch. I
can't imagine it's good for the tree either.

What can I do to rid my poor tree of these pests?


You are describing what is probably the Asian Wooly Hackberry Aphid (Shivaphis
celti Das). While a nuisance because of the honeydew (not sap) they produce,
they most likely will not harm the tree. They are difficult to control because
the fuzzy white material that covers them is waxy and protects them from
insecticides. Many places have had pretty good control with just hosing them
off with a periodic (they continue to reproduce all summer) insecticidal soap
spray. This is especially effective when used in early spring when the leaves
begin to break out, and will reduce the amount of honeydew dripping down onto
your back porch.
Lacewings have shown good effect as a biological control.
sed5555