Hi Chuck and All:

>Until recently there was no known insecticide which would kill the
>beetle. However just recently
>I read that they had found that Imidacloprid was "75% effective"
>against the Asian longhorn beetle.
>The city is undertaking a massive treatment program to try and contain
>the outbreak What effect
>this will have on Chicago and near-suburban beekeepers I don't know.

A Reference:

Sclar, D.C. and Cranshaw, W.S.;  1996;   Journal of Environmental
Horticulture 14 (1)

Injections of Imidaclopride in the soil around the feet of Elms are
particularly effective against principal pests (beetles and Elm aphids).
The persistence is particularly long, such that the pests are under control,
even in the following season wherever the treatment has taken place.

end of abstract quote

If the hardwood trees are types where bees work the pollen, then it could it
be big problem.  If not (like elms, I *think*) then unless there are
flowering weeds under them, it might not be a problem.  The quote is
interesting because it shows that the chemical is persistent for years.

Regards,
Stan