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Photo Credit: ©2002 Dolezal Publishing/John M. Rickard

Toads and frogs are welcome visitors to any garden, eating their fill of flying and crawling insects.

Protecting the environment and working with nature to control pest outbreaks should be a priority for every vegetable gardener seeking healthy, tasty crops. In study after study, organic growing methods reap produce and fruit equal in quality and quantity to those drawn from fields treated with pesticides. How can this be?

The answer lies in the dynamic of insect populations. As with other animals, insects are divided into two large groups: the herbivores (those that eat foliage) and the carnivores (which eat other insects). For any given population of herbivores, a small number of carnivores (or predators) exist to keep the population in balance. Pests that harm vegetable plants are drawn from the more numerous herbivore group. These plant-eating insects reproduce quickly because predator insects, which reproduce more slowly, easily deplete their ranks.

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Photo Credit: ©2002 Dolezal Publishing/John M. Rickard

Organic controls for pests include disbursing beneficial insects, like ladybird beetles, in infested areas.

When pesticides are applied to an insect population, most of the plant eaters – and nearly all of the predatory insects – are killed. Of the small number of each type that remain, the herbivores bounce back faster than the carnivorous insects, since few predators remain to stem the tide. Even more pesticide is needed, then, to control this pest population boom, and the natural balance that once held the two populations in check is destroyed. Pesticides, therefore, aren’t always the best method of action to take.

Scientists studying these control outcomes have reached general consensus about the best ways to manage infestations of harmful insects. The USDA now recommends following an approach called Integrated Pest Management, or IPM, to best take advantage of the natural dynamics of insect populations. With IPM, a small amount of residual crop damage occurs, but surprisingly, that damage is little more than what would be the case if crops were treated with pesticides.