The Benefits of Beneficial Insects and Plants

As gardeners become more educated on the impact of chemicals on the environment, many have embraced the concept of organic/eco-friendly practices and recognize the many choices available. However, when you see an entire crop eaten by an insect literally overnight, the temptation to grab the nearest insecticide still exists for many frustrated gardeners. There is an alternative that does require some planning. Bringing beneficial insects into your garden is one organic answer to pest management.

Spirea aphid and syrphid fly larvae predator. Photo by G. Krawczyk.

Spirea aphid and syrphid fly larvae predator. Photo by G. Krawczyk.

Penn State research states that beneficial insects include lady beetles, syrphid fly larvae and lacewing larvae. These useful insects will eat aphids and scale crawlers. One source of these valuable insects is to buy directly from a supplier and then release them into your garden. Gardeners need to know which problem insects exist in their garden to be able to bring in the correct beneficial for the job. Therefore, gardeners need to research or seek assistance from a local Master Gardener program, such as the Penn State program.

Another solution is to attract beneficial insects naturally by planting host plants right in your vegetable garden. Some of these plants include sunflowers, sage, lantana, basil, cosmos, marigolds, fennel, sweet alyssum, dill, parsley, zinnia, bronze fennel, chives, lemon balm, and yarrow. Many of these are herbs and can blend very well into a vegetable garden.

Beneficial insect research has also been conducted on ornamental peppers. These plants can be grown in both vegetable and perennial gardens, and essentially become a host plant, or “bank,” for the minute pirate bug (Orius insidious). Pirate bugs eat aphids and thrips, but in the absence of prey insects they can survive on the pollen of the ornamental pepper.

These host plants not only attract beneficial insects that assist with pest management, but will also attract pollinators, such as bees and butterflies, and help to re-establish pollinator populations.

Before you reach for an insecticide, consider planting host plants or bringing beneficial insects into your garden. You will be rewarded with a healthier garden as well as a healthier environment!


Joanne L. Fossett
Penn State Master Gardener of Monroe County