March 29, 2014 in Washington Voices

Create welcoming environment for beneficial predatory insects

Pat Munts
 
File photo

A new publication from Washington State University can help identify insects that are beneficial to your garden, like ladybugs. It includes an extensive section on some of the 90 species of ladybug that call this area home.
(Full-size photo)

Garden help

The publication, “Beneficial Insects, Spiders and Other Mini-Creatures in Your Garden; Who They Are and How to Get Them to Stay” is available to download for free at cru.cahe.wsu.edu/ CEPublications/ EM067E/EM067E.pdf

Beneficial insects are the unsung heroes of the garden. We often don’t notice them but they are there, 24/7, devouring bugs that attack plants we like and pollinating our fruit and berry crops. As we begin the spring planting season, now would be a good time to learn about them and plan a beneficial insect-friendly garden.

To help us along this path, Washington State University recently released a new publication: “Beneficial Insects, Spiders and Other Mini-Creatures in Your Garden; Who They Are and How to Get Them to Stay.” The publication discusses more than 40 types of predatory insects found in the Northwest. Some we are familiar with like lady beetles and lacewings, and a few that aren’t usually considered a helpful predatory insect like stink bugs, earwigs and ants.

The heart of the publication is a series of in-depth profiles of predatory insects commonly found in the Northwest accompanied by pictures of the larvae and adult stages of the insects to help with identification. The larval stages of insects are often the most voracious eaters. Understanding the life cycle of these various insects will help you understand when and what to look for in the garden. There is an extensive section on some of the 90 species of lady beetles that call the Northwest home including an all-black mite-eating one.

The second part of the publication focuses on how to get the beneficial insects to stay in your garden. The most effective way to create the proper environment for beneficial insects is to stop using insecticides, especially the broad spectrum ones that kill a wide range of insects including many beneficial insects. We have to learn to live with a certain amount of insect damage because as the bad guys are eating our plants, the populations of beneficial insects are building up and will soon be attacking the undesirables.

To thrive, beneficial insects need a relatively undisturbed refuge with adequate food sources, access to water, shelter from the elements and their predators and places to breed. In the wild, many of them live in moist, riparian areas not much different than a well-watered home landscape. Reproduce this environment by planting and maintaining somewhat wild areas in the garden. Install large blocks of native plants around the garden or in hedgerows along a property line. Living with a few weeds like dandelions may also help draw beneficial insects because some of them are a highly favored source of pollen and nectar.

Lastly, the publication discusses the fact that it is more effective to encourage the development of native populations of beneficial insects than purchasing them and turning them loose in your garden. Purchased insects like lady beetles, lacewings and predatory mites often disperse quickly from your garden as they seek the proper habitat. In some cases, the insects are non-native species that are not adapted to our climate and won’t survive very long.

Pat Munts has gardened in Spokane Valley for more than 35 years. She can be reached by email at pat@ inlandnwgardening.com.


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