don't have a pest identification guide (any www resources appreciated),
but
in the meantime, if anyone can identify the pests at:

http://www.lpmd.org/gardens/spirea1.jpg and
http://www.lpmd.org/gardens/spirea2.jpg

i would certainly appreciate it. they don't seem to be stressing the plant
in any way, but i'm just trying to ascertain (1) what they are; and (2)
what, if anything, i should do about them. i'd like to avoid poisions if i
can.

Ya got aphids there, John. Obviously they're not good for the plant but
the solution is pretty easy and quick -- go down to your local nursery and
buy yourself a whole boatload of lady beetles. In the evening, dump them
all over the shrubs -- they'll eat 'em right up and then likely stick around
to help ensure the little buggers never come back.

You can also use something like Neem or a soap/oil concoction, but ladybugs
are the best way and if you can get the ladybugs to stick around you'll be
REALLY happy to have them (one of the best beneficial insects you'll ever
have in the garden).

James