Beneficial insects working in your garden
- Michelle Wood: SWCD
- October 25, 2009
- 750
We’ve also talked about adaptive pesticides, otherwise known as beneficial insects that prey on pest insects. This approach helps reduce or eliminate the need for toxic pesticides by providing natural pest control for your garden. Doing this also avoids the issue of pests developing resistance to pesticides since the beneficial insects evolve right along with the garden pests.
My friend, Liz, was recently telling about the wonderful wolf spider she located in the basement of her house. As I was excited with her discovery, I was amazed at my companions’ reactions of horror to such a beneficial insect. I have created garden insectaries in the past to attract wolf spiders in hopes of gaining their services to rid me of my aphids, fire ants, and my least favorite: spider mites.
A garden insectary is a small garden plot of flowering plants designed to attract and harbor beneficial insects. These good insects prey on many common garden insect pests and offer the gardener a safer, natural alternative to pesticides.
The garden insectary is a form of companion planting, based on the positive attributes plants can share in deterring pests, acquiring nutrients, or attracting natural predators. By becoming more diverse with your plantings, you’re providing habitat, shelter, and alternative food sources (such as pollen and nectar), something many predators need as part of their diet.
Here’s an example. You can control aphids with an aphid predator like aphidius, and you can encourage the aphidius to set up shop by planting sunflowers or lupin. Of course, the aphid predators need the pests to be present in order to eat, thrive, and reproduce—that is, they need aphids to be found in and around the general area you’re trying to protect from the aphids.
But that’s where stocking your insectary with the appropriate plants comes in.
The idea of inviting the pests in to munch on plants in your insectary may seem alarming, until you understand that you are doing so to encourage host-specific pests. The pests remain on the desired plant in your insectary yet provide an ideal breeding ground for the associated predators and parasites.
Your insectary plot does not have to be large, just big enough to hold six to seven varieties of plants that attract insects. Once the garden has matured, you can watch your personal security force of beneficial insects do the work for you.
A garden insectary should be thought of as a long-term permanent component of your garden.
Results are not instant and conclusive; rather, the benefits to your garden are cumulative. As your plantings mature and resident populations of beneficial insects are established, the need for chemical pesticides and other aggressive insect control techniques will diminish. Your garden will become a more natural and balanced environment for the healthy production of vegetables and flowers.
Until next week, this is Ruth the Grower saying, “Liz, no matter what others tell you, finding a wolf spider is a true sign to no more ants in the house.” Keep writing to ruththegrower@aol.com.