Pesticides Harm the Environment 273
Resistance to pesticides
There are always a few pests that do not die
when they are sprayed because they are
stronger or have chemicals in their bodies that
block the pesticide. They give birth to other
pests that have the same strengths and are not
harmed by pesticides. This is called pesticide
resistance. More and more pests are born with
resistance, and that leads to a whole population
of resistant pests that can no longer be killed
with the same chemicals.
How pests become
resistant to pesticides
Pesticide companies then create new
or stronger pesticides to kill resistant pests.
Farmers buy the new chemicals, spending more
money each season. Each year the environment
is poisoned with more chemicals, more pests
become resistant, and the pesticide companies
make more profit.
The pesticide kills most pests,
but some survive because
they are resistant.
While pesticides may reduce crop losses from
pests for a few seasons, in the long run they
poison people, animals, the ground, and the
water. The only long‑term benefit goes to the
chemical companies that make and sell them.
Pesticides kill helpful insects
Not all insects are pests. Many insects are
helpful to farmers. Bees pollinate plants and make
honey. Ladybugs attack insects that damage
crops. There are more helpful insects than there
are “pests.” But pesticides usually kill both the
“good” insects and the “bad” insects.
The pests that survive give
birth to more resistant pests.
For example, when a field is sprayed to
kill aphids, the poison also kills the spiders
and ladybugs that eat aphids. Without spiders
and ladybugs to control them, more aphids
come back.
Soon, all the pests are resistant,
and pesticides no longer work.
A Community Guide to Environmental Health 2012