On Mon, 12 May 2003 23:04:36 GMT, "seepnezorf1"
wrote:

I'm in zone 6 and our guide books tell us that for taking care of lilacs and
systemic insecticide must be used. What exactly is that and what makes it
different from a regular insecticide?


A systemic insecticide is absorbed into the plant tissues, then kills
the insect when the plant is consumed. Other insecticides kill
insects by direct contact, usually blocking their breathing pores
(stoma) leading to suffacation. One advantage of a systemic
insecticide is that it remains active after a rain. Systemic
insecticides should not be used on human-edible plants.