Tips for Gardening Organically with Beneficial Insects
A healthy garden hosts a balanced amount of both good and bad insects. When pests start destroying your plants, it’s time to consider introducing beneficial insects to keep out-of-balance populations in check.
Experts Advocate Beneficial Insects Versus Pesticides
Keep in mind that pesticides don’t discriminate because they’ll kill undesirable bugs and the good bugs who would otherwise eat them. Wiping out the first wave of pests may lead to an even feistier second wave of other pests who may move into the area because you’ve knocked out their natural enemies.
Pesticide residue can remain on garden vegetables even after a thorough washing and can be a threat to curious children and pets.
Also, over 500 insects now show immunity to conventional pesticides. But, there aren’t many insects who are resistant to being eaten!
Ladybugs Are the Best
Though there are over five hundred different species of ladybugs, we are most familiar with the seven-spotted ladybug called Hippodamia convergens. They sure are pretty but ladybugs are good bugs to have in the garden due to their predatory characteristics. Their larvae nosh on scale, mealybugs and spider mites, but they love aphids–eating as many as five thousand in their lifetime.
Common in San Diego gardens, aphids feed on plant sap causing distorted leaves and flowers. And, almost every plant out there has a type of aphid that likes to feed on it, even water-wise succulents. Spring is when aphids thrive as new growth starts to appear on plants. There’s no need to identify the exact type of aphid as ladybugs and other beneficial insects typically don’t discriminate.
San Diego: Free Garden Ladybugs at Armstrong Garden Centers –
“One of the biggest trends in gardening this year is growing your own produce,” states Eric Asakawa, Regional Manager of Armstrong Garden Centers. “Spring time is the best time of the year to begin growing warm season vegetables such as peppers, tomatoes, zucchini, cucumbers and herbs. Ladybugs benefit your garden by providing an organic method to control unwanted pests, which allows you to create a healthy, long-lasting garden.”
This weekend, free ladybug packets are available at Armstrong Garden Centers (while supplies last,limited to one per family). Armstrong Garden Centers is also hosting a free class on ladybugs and other good insects for your garden, along with other fun interactive activities for kids. The action happens on Saturday, April 26 at 9:00 a.m. On April 27, there will be another free class on organic gardening at 11:00 a.m.
How to Release Ladybugs –
Armstrong Garden Center suggests placing the ladybugs in the refrigerator for 30 minutes prior to applying them to affected areas in the yard (this is a common practice and considered safe for the ladybugs by experts). Then, spray the lower leaves of your infested plants with water and sprinkle the ladybugs on the lower 1/2 of each plant. Release the ladybugs in the evening.
Refrigeration slows their metabolism down, basically putting them to sleep through the night. When the sun comes out the next morning, their instinct is to climb up the plant in search of food. When they find aphids, or other small insects to feed on, they will feed and then lay eggs. They may fly away in search of other aphid-infested plants, but their eggs will then hatch hungry larvae who will also feed on the same pest insects. A ladybug cycle of life is now in your garden.
The larvae of green lacewings are active predators of eggs and immature stages of many soft bodied insect pests like aphids, caterpillars, mealybugs, scales, thrips, and whiteflies. They eat for 2-3 days, spin a cocoon and then emerge as adults 10-14 days later. Adults feed on nectar, pollen, and aphid honeydew but they do lay eggs, hence repeating the cycle.
Lacewings have a light green or brown bodies and grow up to about an inch in length. You probably have some in the garden, if you have native shrubs, flowers and trees. Some gardeners attract lacewings to aphids by spraying a mixture of sugar water (1 tablespoon of sugar for every one cup of water) to infestations. The sugar water causes aphids to release honeydew, which attracts lacewings.
Local nurseries begin to stock praying mantis eggs in the late winter in early spring. These insects will eat any insects, even beneficial ones. And, when we say they don’t discriminate, we mean it because in a food shortage they’ll even eat themselves.
But, generally, praying mantis are good solutions when there is an abundance of pests. They’re about 2-4 inches long, can spin their heads around and can even make eye contact with you.
Hover Flies (Otherwise Known as Flower Flies or Syrphid Flies)
Have you ever wondered what these little bee-like flies with striped abdomens are? The answer is extremely beneficial to your garden. Hover flies feed on pollen and nectar provided from flowers. Adults lay eggs that hatch into aphid-loving larvae that are able to get into little nooks and crannies other beneficial bugs have trouble accessing. They even hatch in the spring prior to when other beneficial insects normally become active.
Also, because hover flies feed on flowers, they provide a service to the ecosystem by pollinating them, too.
A Nod to a Childhood Favorite: Pillbugs
Often referred to as sow bugs or roly poly bugs, pillbugs are nature’s composters. Fun for the kids in the garden to take a close look at (and dare we say, play with), these crustaceans roll into a ball when feeling threatened. Though pillbugs are not insects. Did you know they are related to lobster? Don’t panic if you see a few cruising through the yard as they keep soil healthy.
Pillbugs will start to destroy plants when their populations are out of control. The best thing to do is to remove hiding places that lock in moisture (where they love to hang out) such as leaf piles or rocks. Also, watering in the morning so that the soil is dry at night when they’re active, helps tremendously.
Learn to Distinguish Garden Pests
Sure, most of us know what an adult ladybug looks like but their alligator-like ladybug larvae are often mistaken for pests. The same goes for lacewing larvae (pictured above). Learn to tell the difference before reaching for pesticides.
Take it one step further by actually learning about the enemy. Understanding life cycles and habits will help you manage an outbreak.
Plant to Attract Beneficial Insects
Consider planting a row of scented fennel, calendula, coriander, dill, and cosmos around vulnerable plants to attract ladybugs and the like. However, flowers in general with their pollen and nectar naturally attract them, too.
Have you introduced beneficial pests into your garden?
Photo credit: top, freeimages/afranklin; praying mantis, Flickr/ikewinsk; hover fly, Flickr/wackybadger; lacewing larva, Flickr/usdagov