This post is the third in a series of posts on the control of pests.
The third question a gardener has to ask is “Will the pests spread to other plants?”
Knowing about  the pest that is affecting your plant is important so that you can know enough to outsmart the insect with the minimum amount of force or effort. Some insect pests love many crops while others insect prefer only one family of plants.
The insects that eat only one family of plants are easiest to eradicate. By getting rid of the family of plants, you eliminate that insect population. Sadly, that is what is happening to the Monarch butterfly. The Monarch butterfly’s caterpillar can only feed on the asclepias or milkweed plants – no other plant family. Milkweed is a weed pest on farms and are destroyed when builders build houses with gorgeous lawns. So the Monarch butterfly is dying out.
Insect pests that eat a wide range of plants are more difficult to eradicate but many can be foiled or eliminated without toxic chemicals. More about this in a later post.
When a gardener opts to use chemicals that kill harmful insects, remember that most of these insecticides will kill the beneficial insects as well. Most insecticides are equal opportunity insect killers, not being able to discriminate.
Ami Zumalt of Odessa, a certified organic farmer and owner of Red Ridge Farms in Kansas, said that “There are more than 1 million species of insects in the world, and only less than 1 percent are considered harmful,”