Gardening tips: Using beneficial insects to manage landscape pests

Pest management for your lawn and garden is a personal choice. You choose what fits best according to your gardening philosophy.

My job is to provide you with all of the options that are available, and one of those options includes biological controls.

Biological control occurs when you use one organism to control another. For instance, ladybugs feed on aphids.

My approach to using biological controls is three-fold. The first is to be able to identify the good guys, or the bio-allies. The second is to attract them to the landscape. The third is to protect them and avoid pesticides if not necessary.

Identifying these bio-allies takes a little bit of practice and experience. Once you learn as much as you can about them, you begin to start looking for them and actually finding them.

The biggest issue here is that you have to look for them in the garden just as you would be looking for the bad bugs. Get up close and personal with your plants in order to find these good guys.

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Ladybugs are the most recognized good bug. The adults and larvae feed on soft-bodied insects such as aphids and some scale species.

Other good guys include lacewings, syrphid flies, wasps, praying mantids, soldier beetles and more. Doing an internet search for these will provide you with details and photos so that you can begin to identify them in your garden.

A few years ago I had an infestation of aphids on my tomato plants. While inspecting the plants, I also found lacewing adults, larvae and their eggs. I decided to do nothing. After about 10 days, the aphids were gone and no pesticides were used.

Attracting the good guys to your landscape is done by determining the types of plants that are attractive. Plants in the carrot and mustard family are good for attracting beneficial insects.

Plants that attract these insects also include small flowering plants such as sweet alyssum, dill, fennel, cilantro and lovage. Coneflower, coreopsis, tansy, yarrow, goldenrod, sunflowers and cosmos also attract the good bugs.

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Again, after planting a variety of flowers to attract good bugs, get close to the flowers and watch to see what visits and begin to identify the beneficial insects.

Lastly, protect those that you attract. Avoid using pesticides if possible. If you need to spray, select pesticides that are considered “soft,” or the least harmful to many beneficial insects.

For instance, insecticidal soaps and summer oil sprays are used to kill aphids but won't affect ladybugs once they dry. However, they will kill the good guys if you spray them directly. Therefore, once again, inspect and make sure you don't have good guys on the plants prior to spraying.

I rarely use pesticides in my lawns and landscape, and I try to use the above practices first. I only spray if things are really out of hand and I might lose a plant or the flowers will be destroyed (hibiscus blooms, for instance).

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