Safefertilizer’s Weblog

Insect 101

As a natural gardener, you will need to wrap your
brain around one thing: you have to get used to
a little bit of insect damage. The only
alternative is to live awash in highly toxic
pesticides­both organic and natural. The only
way to completely eliminate insects is to
constantly apply pesticides. One or two
applications do not do the trick because the
surviving insects will breed, and never
leave. There are so many things a gardener needs
to know about insects in their gardens­, some of which may come as a surprise.

Pesticides aren’t always the best solution.

Beneficial Insects

Not all insects are considered “pests.” Some
insects are highly beneficial. The drawback to
applying pesticides, both organic and synthetic,
is that broad-spectrum pesticides kill every
insect in reach, including beneficial
insects. This wide-scale destruction destroys
the balance of insects, good and bad, within the
garden, usually resulting in more insect damage,
and the need to continually apply pesticides.

The most commonly known beneficial insect is the
ladybird beetle, or “ladybug.” Ladybugs are
carnivores! These cute critters love to eat
aphids and other soft-bodied insects. Another
beneficial insect is the lacewing. The adults
are lovely with sheer green wings. The larvae
look like little dinosaurs and are chewing
machines. They also eat mites and aphids with abandon.

Insect Damage Threshold

Backyard gardeners and commercial growers each
must establish what is called a tolerance
threshold for insect damage. As a home gardener,
you have the luxury of setting your threshold
much higher because your tomatoes don’t have to
look perfect for your own use on salads and juicy
burgers. All plants will sustain some insect
damage, that’s a given. In order to reduce your
need for pesticide use, sometimes you just need to lower your expectations.

Applying Pesticides Does not Make Pests Go Away

Each yard, each city, county and state are made
up of delicately balanced ecosystems. The
healthiest ecosystems are generally those
untouched by human hands because they are
composed of naturally occurring and diverse
species. If an insect pest is introduced to a
well-balanced ecosystem, it may damage some of
the plants, but certainly will not damage all of
them. The reason that large farms require so
much in the way of insect control is that most
large scale farms are composed of fields of
thousands of the same type of plant. If an
insect that likes that plant comes in, the farmer is out of luck.

Home gardeners have the luxury of growing
flowers, shrubs, trees and vegetables in their
own diverse, if not naturally occurring,
blends. Doing so helps avoid some insect
problems. The other way to avoid insect problems
is to avoid using insecticides. Damaging insect
populations naturally cycle. Insect numbers grow
and grow until their population is so large that
it cannot sustain itself with the available food
sources (your garden). Then, the population
crashes and you have few, if any, problems with
that pest for several years. This is called
“overshoot,” and is illustrated in the diagram below.

Applying pesticides disrupts this natural
cycle. Applying pesticides actually helps
sustain a fairly steady insect population. So,
instead of having a lot of insects one year and
no insects the next, you have some insects all of the time.

Additionally, insects have rapid life cycles, and
can quickly develop resistance to pesticides, as
illustrated by the diagram, below.

Diagram from Manitoba Agriculture, Food, and Rural Initiatives Program. 

Insects in the garden are frustrating, yet
beautiful and necessary. The most important
general tip for dealing with insects over time is
to think before you act. This will allow you to
make the decision that is best for the effective caretaking of your garden.