Bugs can help keep ‘bad guy’ insects in check

It’s still officially spring, but we’ve had a lot of summerlike weather lately. Our perennials are up and starting to think about flowering, the annual flowers add color to the now-died-out bulb beds, the vegetable garden is planted, and we’ve worked hard to control the weed population that exploded with all the spring rains.

Now we turn our attention to what’s bugging our gardens – the insects that we see in increasing numbers as the season progresses.

Approximately 1 million insect species have been identified worldwide, and more than 90,000 live in North America. The beetle, fly, moth/butterfly, and wasp/ant/bee insects constitute the majority of all species.

Believe it or not, less than 1 percent of all those types of insects are serious pests that affect our animals, our gardens or us. These can include aphids, spider mites, whiteflies and leafrollers. Far outweighing the bad guys are the beneficial insects that pollinate flowers and vegetables and attack insect pests.

We gardeners need to learn the difference, and an insect identification handbook can be invaluable in figuring out whether that big-eyed bug on your potato plant is going to eat the plant or eat the bugs that are eating your plants.

The trick is to determine whether the damage on your plants is even caused by insects in the first place, or whether cultural practices or disease may be the culprit.

If you do decide insects are to blame, keep in mind that many of the “bad guys” are prey for the “good guys” and are often controlled by them.

If you immediately attack with heavy weapons (toxic pesticides), you might make things worse. Many chemical pesticides are lethal to all insects, so if you spray your garden, you may end up killing the very ones that are best suited to control the infestation, thus disrupting the balance of nature and opening the door to a new infestation of “bad guys.”

So how do we recognize who the good guys are?

Everyone knows ladybugs (properly known as lady beetles) are fun to have around, but I bet you didn’t know they are voracious predators (both adults and young) that will gobble up aphids, scale insects and spider mites, among others.

Another common insect many of us find in our gardens is the praying mantis. Kids like to play with them because they can be counted on to fight a blade of grass or a small stick with their front legs.

They will attack and consume almost any insect they come across, even good guys, and are cannibalistic as well!

Lacewings are among the most beautiful of the beneficial insects, with their green or brown lacy wings (aren’t they aptly named?) and big eyes. They love to eat aphids, but they feed on other species as well.

Dragonflies can be almost as pretty as lacewings; they too have translucent wings and iridescent bodies that gleam in the sunlight. They eat flies and mosquitoes, and their aquatic young also attack immature mosquitoes.

Take a walk around your garden today and try to find the “good guys” – and then create an environment that will encourage them to stick around.

Besides eating “bad guys,” lots of good guys like pollen, so a wide range of pollen-rich plants such as sunflower, yarrow and daisy will attract and keep them in your garden.

This week in the garden

• With the weather warming up, set up a regular irrigation schedule and consider installing drip irrigation. For information on how to plan and install a drip system, see a free fact sheet available at the Master Gardener Web site. The address is www.spokane-county.wsu.edu/spokane/eastside. Look for the link to Free Fact Sheets, choose the Sustainable Landscaping icon, and select CO191 Drip Irrigation. If you don’t have access to the Internet, come by the Master Gardener Plant Clinic at 222 N. Havana St. or call 477-2181. We’ll be glad to mail you one.

• Mow your lawn regularly to a height of 2 to 2½ inches. Keep mower blades sharp. Lawns need about an inch of water a week. Water deeply once or twice a week.

• It’s OK to plant tender annuals and vegetables, both transplants and seeds.

• Fertilize rhododendrons and azaleas after they are finished blooming. This is also a good time to prune them if they need it.

Don’t prune later in the summer; they will be forming new buds for next year’s flowers.

• Wait for spring-flowering bulb leaves such as daffodils and hyacinths to die down before removing them; they are sending needed nutrients to the bulbs. But a month to six weeks after iris are finished, it’s OK to cut the leaves down to a few inches above the ground.

Now is also the time to divide and replant bulbs.