If you plant it, they will come!

Last week our friend Mike McGroarty sent advice about how beneficial insects can help us fight plant-eating insects in our gardens. But if there aren't any beneficial insects in the garden, they can't come to our aid. This week he tells us how to attract beneficial insects.

There is a variety of common plants and flowers that attract beneficial insects. Beneficial insects are not only attracted to plants which are infected with their insect prey, but they also tend to be selective about the plants on which they lay their eggs. Many beneficial insects also spend part of their lives surviving on the nectar and pollen of their favorite plants. Ideally, your garden plants will provide food, shelter and a nursery for beneficial insects. Some of these plants
may already be in your garden.

Caterpillars, leafhoppers, beetles, moths and grubs are attacked by tiny parasitic wasps. Because they are so tiny themselves, parasitic wasps prefer tiny flowers when they want a drink of sweet nectar. Parasitic wasps will frequent a garden that features some yarrow, dill, parsley, Queen Ann's lace or tansy. These umbrella-shaped flowers are very attractive to a number of beneficial insects.

Green lacewings and ladybugs will also appreciate the same umbrella-shaped flowers. They also like cosmos, prairie sunflower and even dandelions and alfalfa. Lacewings prefer to lay their eggs in shady areas that are protected from the weather. They'll be happy to find some of their favorite plants in a quiet, protected corner of the garden.

Various herbs are attractive to some beneficial insects. Adding some herbs here and there amongst your flowers or vegetables will surely lure some beneficial insects to work in your garden. Lemon balm, pennyroyal, spearmint and parsley will attract hoverflies, parasitic wasps and tachinid flies. Tachinid flies look like hairy house flies. They lay their eggs on caterpillars, which can do a lot of damage in a garden. Tachinid fly larvae will destroy corn earworms, cabbage worms, armyworms, and other fly larvae.

Providing the proper plants for food and shelter is just one step toward attracting beneficial insects to your garden. The most important thing is to stop using chemical pesticides. Chemical pesticides are not selective and will kill both harmful and beneficial insects. Many organic insecticides are selective and when used properly, will not harm the beneficial insects.

Thanks, Mike!