Many common insects are truly beneficial because they seek and destroy insect pests.
This small, but important group of insects, includes both predators and parasites. Common
predators include ladybird beetles, ground beetles and praying mantids who feed directly on
pests. Parasites include several tiny wasps and some moths and butterflies. Most go unnoticed
or are mistaken for harmful insects. They are one of natures ways of keeping insect pests in
check but often their number may be insufficient to control a pest outbreak. Beneficial insects
occur naturally but many can also be purchased locally at specialty stores or mail ordered.
Beneficial insects can and do control insects but results are often mixed. Several factors
increase their effectiveness. First, there must be insects present for beneficials to eat or
parasitize. If food isn't available or is eaten up, the beneficial will go elsewhere to find food.
This also means that you will have to tolerate a low level of pest insects in your garden to
provide food for the beneficial insects.
Ladybugs are more likely to stay close to the release site if a water source is available.
This could simply be droplets of moisture from a hose sprayed on nearby plants. Ladybugs are
also less likely to fly away if they are released in the evening hours and spend their first night in
When using benefical insects be very careful when using certain pesticides. Broad
spectrum pesticides will kill beneficial insects as well as pests. If you do need to use pesticides
spot treat only and avoid treating large areas to limit damage to beneficial insects. Insecticidal
soaps and horticultural oils are good choices should a spray be necessary to reduce the damage
level before beneficial insects are introduced or their population builds naturally in the garden.