Not all bugs are bad. Many gardeners are learning to leave good bugs and tolerate a bit of plant feeding. Some of us are also using plants to attract the good guys. My colleague Richard Hentschel, University of Illinois Extension horticulture educator, explains more below.
"There are a number of predator insects that can help us control the destructive ones," said Hentschel. "The commonly known ones include several versions of the lady beetle. Both the adults and larvae feed on aphids. Ground beetles also feed on both adults and larvae of destructive insects such as root maggots, snails, slugs, caterpillars, and weed seeds.
"Other lesser known predators are pirate bugs, damsel bug nymphs, and assassin bugs," he added. "These three feed on soft-bodied insects that damage our plants. Lacewing larvae feed mainly on aphids mainly whereas the adults also use nectar and pollen as food besides feeding on aphids."
"To attract and keep these predator insects in and around the garden, there are a couple of conditions that need to be met or maintained," Hentschel explained. "Without a food source of destructive insects, the good guys will go elsewhere. Without a small population of their prey on your desirable plants and vegetables, there will not be a population of predator insects when you need them.
"The other condition is a need for host plants that attract the predators into your yard. These can be cultivated flowers or more native plants. Coneflower and coreopsis are native and have interesting flowers. Cup plant and yarrow also are attractive and native. Some less ornamental plants could be wild carrot and parsnip. These two and those already noted are perennials. Anytime you have plants that self-sow, managing the plantings is needed so you do not end up with the proverbial weed patch that can be a problem in the neighborhood or for immediate property owners."
Hentschel added that there are many more plants that can be used, depending on where the home is located. Homes in more rural settings and with larger yards have more choices, he said.
"You can find plants in the carrot, aster, mustard, and legume families that could be considered ornamentals and natives," he said. "If you are going to establish insect predator-friendly plantings, remember that you will need to take care of those plants just like you do for other plantings until they are established."
Learn more about Beneficial Insects: Garden Warriors during an upcoming Four Seasons Gardening Webinar when horticulture educator Kelly Allsup discusses the most common good guys. The program is presented live for live home viewing on July 10 at 1:30 p.m. and again on July 12 at 6:30 p.m. Following the session, a taped version is available on YouTube. Registration and YouTube information are found at http://web.extension.illinois.edu/hmrs/4seasons.