Pesticides are chemicals formulated to kill living organisms. The suffix “-icide” means “to kill”.
Pesticides are divided into categories such as insecticides, fungicides, and herbicides. While a pesticide typically targets one or a few types of organisms, its effects are often not confined to the target. Some of the ingredients in pesticides are known to be human carcinogens, while many of the ingredients have not been tested for their human health effects.
For this reason, pesticides can be more dangerous than the organisms they’re meant to eliminate. Dandelions are harmless, and fewer than 1% of insects cause any trouble for people. In Madison, insect problems are rare enough that preemptive pesticide use is not warranted. If a problem does arise, ask a qualified entomologist for advice. Be wary of asking an exterminator – remember that they have a financial incentive to exaggerate the problem.
If you do choose to use pesticides, read the label carefully and follow the instructions exactly. Using a pesticide in any other way is a violation of federal law.