The Underappreciated Value of Predatory Beneficial Insects in the Garden

Before getting into what additions were made to “Attracting Beneficial Bugs to Your Garden” between the first edition and the second edition, Jessica likes to highlight what was removed.

When the first edition was published in 2014, Jessica went on a speaking tour to botanic gardens and gardening organizations and she gave a lot of interviews about the book as well. She had expected that gardeners were interested in how they could plan and design a dedicated insectary border for the good bugs, much like a pollinator garden, but she found that was not the case. The gardeners she met didn’t want to create a new garden just for beneficial insects; they wanted to know how they can take the garden they already have and add the right plants and adopt the right practices and care techniques to make it a more welcoming environment for beneficial insects.

“They want to know how they can enhance what they already have rather than change or put something brand new in,” Jessica says.

A section with garden plans, maps, illustrations and plant lists was removed in the new edition because Jessica discovered that gardeners did not find it to be approachable or doable. So in the new edition, she addresses the question, “How do we make what we already have better for the bugs?”

Additions to ‘Attracting Beneficial Bugs to Your Garden’

In the eight years since the first edition of ‘Attracting Beneficial Bugs to Your Garden,’ there has been new research on native plants and how they impact beneficial insects in some really cool and fascinating ways, Jessica says. Scattered throughout the new edition are interviews with entomologists from throughout the world offering “a fascinating peek at their current research and things that we as garden people might not have thought about.”

One of the interviews is with Dr. Doug Tallamy of the University of Deleware. “I was able to include this great interview that connects native plants to beneficial insects in a way that surprised me, that I hadn’t thought of even after reading all of this research so that was a pretty exciting addition for me,” Jessica says.

Jessica notes that when we think about what to plant for beneficial predatory insects, we often think in terms of flowers that will supply nectar, which provides carbohydrates that many insects need to reproduce. She wondered if native plants have better nectar for native predatory insects, but Doug says that’s likely not the case. While some pollinators may require nectar that is a perfect match, for predatory insects, nectar is just nectar.

Doug explained that native plants are important to predatory insects for another reason: They host the insects that become prey for predators. For example, native oaks trees host sphinx moths, which are prey for Cotesia wasps. Having Cotesia wasps around your garden is a boon because they also prey on tomato and tobacco hornworms (which are also sphinx months).

“If you don’t have those trees around, you’re not going to have alternative hosts for those parasitic wasps,” Jessica says. “So when you get the tomato hornworms, the wasps aren’t going to be there.”

So in addition to all the flowers Jessica plants to attract predatory insects, she has many trees and a great diversity of plants around her landscape — not just in the vegetable garden — to support them. She calls it another layer of bricks in the foundation that good bugs need to stick around in your garden.

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