We have had a widespread and heavy infestation of what looks like a white wooley aphid on Chinese Hackberry trees this year.
The trees began dripping honeydew in early summer. I have never seen so much honeydew!
I would like to find information about monitoring this pest, to see if it will be a problem next year.
Another fellow worker has charge of pesticide applications, and he has suggested using a soil drench systemic during the dormant season.
Many of the trees have very limited soil exposure due to pavement. Also, I am wondering if treating all the trees in the area is a bad idea. It seems to me that lesser affected trees might be harboring beneficial insects, which might be harmed.
Can someone with more understanding of IPM give me a clue here?
The trees are in and adjacent to parking lots. They have not had this problem every year. The location is Northern California Sacramento Valley.

Reply to post by Mark Goodwin, on October 24, 2002 at 11:02:34:

By the way, the soil drench systemic is 'Merit'.
And the applicator intends to apply the material every year to all trees of this species indefinitely, without monitoring, as a prophylactic.
Does anyone see a problem with this approach? Anyone have relevant experience they wish to share? Thanks.

Reply to post by Mark Goodwin, on October 24, 2002 at 11:02:34:

For anyone interested, there is some information about the aphid pest at the site linked below.

Reply to post by Mark Goodwin, on October 25, 2002 at 11:10:14:

The City of Chico announced this week that it was treating 1200 Chinese hackberry trees with a soil drench of 'Merit' insecticide to control the Asian wooly aphid problem.

Reply to post by Mark Goodwin, on November 26, 2002 at 13:09:32:

Systemic tree injections of merit would be more efficient then soil drench. The later has proven to lead to long term residual quantities of merit found in the soil and eventually drinking water. Injected Merit would not kill beneficials directly, but may kill them if they feed in aphids with sublethal doses as imadiclorprid would would accumulate in a preditor feeding on many such prey.