About kathyedoisy

I'm a retired MU entomologist and stream ecologist. I've been an avid gardener for over 40 years and love to cook and preserve what we grow in our garden.

The Boone County Buzz: Beneficial Insects for Your Garden

Kathy Doisy

Kathy Doisy

Garden leader Calvin Miles, from Friendship Garden Club, recently asked me a very good question, “What are the good insects?”

Well, first off, we want pollinators. As I mentioned in my last post about “insect hotels,” these include honey bees, bumble bees, solitary bees, ants, butterflies, moths and some flies. Where this gets tricky is that some butterflies and moths are actually laying eggs so their young can devour your crops. I could go on (and on, and on), but, generally, if you see a butterfly or moth hanging around your cole crops or corn it is probably laying eggs because these plants don’t require pollinators. Of course, it may also just be taking a rest. One rule of thumb is that if it’s a pretty butterfly, give it a nudge to move it along. If it returns and especially if it’s white or yellow, get rid of it if you can.

So, beyond pollinating many of our crops, insects may be beneficial to our gardens by consuming other insects and relatives that damage our crops. There are dozens of these beneficials, so I’m just going to address the ones I most commonly see in my Columbia garden. Then I’ll list some good websites for readers who want more information.

Most everyone knows what a ladybug looks like. Maybe you also know that they help our gardens by eating aphids and other small plant pests. Did you know that immature ladybugs do the same thing? They range from a few millimeters to ½-inch in length. Here is picture of one so you know to leave it alone or move it to a plant with an aphid infestation!

ladybug larva, photo by Mausy5043

Ladybug larva

Another good type of insect to find in your garden is a praying mantis. There are three species found in Missouri, ranging in size from about 2½ to 5 inches, and in coloration from brown to bright green. These feed on most anything they can catch, even including, on rare occasions, hummingbirds. I’ve seen a picture of this and actually found a pair of hummingbird wings mixed in with the butterfly wings beneath one of my Chinese mantises! Survival of the fittest, right? EEK! That said, put a mantis on your green bean plants and forget about leaf damage.

praying mantis

Praying mantis

Lacewings are another great predator. The adults and young both eat aphids, small caterpillars, mites, etc. (and fortunately not hummingbirds). The adults are about ¾-inch long and may be green or brown. Larvae are about a ½-inch long and brown.

adult & immature lacewings

Adult lacewing, left. Immature lacewing, right

Stink bugs…are way too complicated. Generally speaking, stink bugs feed on our crops and damage them by sucking fluids. However, a few species of stink bugs suck the juices out of all
kinds of crop-destroying caterpillars. Unfortunately, even I can’t tell the good guys apart from the pest species without a magnifying glass. While all stink bugs have long, tube-like mouthparts, the predators have a broader tube than the plant feeding types. So, unless you find a stink bug in the process of killing something else, you might just go with the odds and kill any that you see. (If you’re game to try sparing the predatory species, though, read to the end for a couple good guides to common species.)

green stink bug

Green stink bug

Another group of beneficial predatory insects I often see is damsel bugs. There are quite a few species you may encounter. The one I frequently see is brown and about a ½-inch long.  These are true bugs (like stink bugs) and, therefore, grab their prey and use tube-like mouthparts to suck the juices from a variety of caterpillars, leafhoppers and other garden pests.

damsel bug

Damsel bug

So that’s just a few of the more common beneficial insects. There are also dragonflies, ground beetles, ambush bugs, assassin bugs, predatory and parasitic wasps, predatory flies, and our non-insect friends the spiders and some mites. To learn more, check out some of the websites listed below.

More information on beneficial insects and how to attract them:

More information on stink bugs:

The Boone County Buzz: Introducing Insect Hotels

Kathy DoisyHi! My name is Kathy E. Doisy, and I am a new board member for the Community Garden Coalition. I have always admired this organization because it helps so many people, and it’s completely volunteer. I’ve been an avid gardener since 1976, and I’m a retired entomologist so I have a lot of knowledge about gardening and garden pests. As the season goes forward, I’ll be posting timely information about common garden pests in a column we’re calling “The Boone County Buzz.” In the meantime I thought I might suggest a way that you can prepare for next year’s crops and help the environment at the same time.

I think we all know that insect pollinators are important for the production of many of our favorite fruit and vegetable crops. When you mention pollinators most people think of honey bees which are a lovely, beneficial species. But did you know they are not native to North America? They were introduced into the New World by Europeans. However, North America already had a huge diversity of native insects that act as excellent pollinators, including bumblebees, solitary bees, moths, ants, butterflies, and some flies.

I’ve been trying to encourage these native species in my garden for several years because it’s a LOT easier than being a beekeeper! Then I heard about “insect hotels.” Just type that or “bug hotels” into your favorite search engine, and you will be inundated with pictures and articles about how to build one for your yard or garden. I don’t know whose idea this was but it’s a good one! Below are few good websites for your perusal. I encourage you to help our native pollinators while also helping your garden!

How to build an insect hotel:

Detailed information on our native bees:

And here is my own new insect hotel:

Kathy's insect hotel

Gardening Courses

The Columbia Area Career Center has several classes happening this spring that might be of interest to gardeners. These paid classes are offered by the Columbia Public Schools through the Professional and Community Education Program.

For information on dates, prices, class openings and online registration go to:

ALSO: Mid-Missouri Expo—Small Farm to Backyard Garden is being offered by the Boone County MU Extension on Saturday, February 24 from 9 a.m. to 3 p.m. at Battle High School. There are going to be four topic areas with five concurrent sessions running on topics ranging from growing mushrooms, raising tomatoes, organic gardening, small animal rearing, pruning and much more. Pre-registration $7, door $10.

For more information go to http://extension.missouri.edu/boone/mid-moexpo.aspx

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