Pesticides are composed of synthetic and/or organic compounds. Many gardeners have shied away from the use of synthetic pesticides in favor of organic. Organic pesticides are those pesticides that come from natural sources, usually plant-based and therefore less feared, but while organic pesticides are normally safer than synthetic, safer does not mean harmless.
Even if the product is considered organic, it is still a pesticide and the consumer must be aware that many organic pesticides are more toxic than their synthetic counterpart. Some organic pesticides that are considered nontoxic or only slightly toxic to humans can be very toxic to animals. Some organic pesticides are very toxic to fish when carried away by storm water runoff.
Pesticides are one of the main groups of Persistent Organic Pollutants or POPs that are presently polluting lakes, rivers and streams throughout North America. Also, organic or plant-based pesticides aren't selective; they will kill the beneficial insects such as honeybees and ladybugs along with the unwanted pests.
The one benefit found when using organic versus synthetic pesticides is that many organic products break down much faster than do the synthetics. This means the threat to humans, pets, wildlife and beneficial insects is of a shorter duration than with most synthetics.