Garden pests like aphids, cucumber beetles and spider mites can wreak havoc on a garden, leading to withered or weakened plants. But not all bugs are a menace to your yard.
In Good Garden Bugs: Everything You Need to Know About Beneficial Predatory Insects (Quarry Books, Beverly, Massachusetts, 2015), entomologist Mary M. Gardiner, PhD, encourages gardeners to resist the impulse to squash bugs on sight or to lay on the pesticides. Instead, she describes the beetles, wasps, spiders and other arthropods that can help protect a garden from pests naturally.
When encountering the damaging effects of insects in the garden on a regular basis, it’s easy to lose sight of how helpful some insects can be, she writes. But believe it or not, many insects actually provide beneficial services to gardeners.
In the book, Gardiner describes natural predators and details their life history attributes and behavioral traits. It’s not enough to know that a certain bug will eat a pest, she notes; it’s also important to know more, such as which insects consume garden pests in the larval stage, and which are more active as adults. That way gardeners can help select the most appropriate predatory insect at the right stage of its life to address their garden pests.
All the insects in the book are in the phylum Arthropoda. Within that group, Gardiner describes members of the Insecta, Arachnida (arachnids), and Chilopoda (centipedes) classes. There are more than 200 photos. The majority of the images are from the website bugguide.net, which is hosted by the Department of Entomology at Iowa State University.
The 176-page book’s descriptions and illustrations of bugs’ predatory behaviors can be fascinating. Tiger beetles larvae, for instance, construct narrow burrows perpendicular to the ground, then lie in wait until prey comes within striking distance. They typically eat arthropods, and can take up to three years to mature to an adult stage.
Parasitoid flies lay their eggs in or on a host; as the larva develops, it consumes the host, eventually killing it. One parasitoid, the feather-legged fly, attacks squash bugs, a common garden menace, while others may feast on cucumber beetles or caterpillar pests.
Some insects will be familiar sights to gardeners, while others will be new discoveries. Stinkbugs and ladybugs are among the insects we’ve probably all seen – often in our homes, not just outside of it. Spider wasps, on the other hand, are native mainly to the southwest, and will be unfamiliar to many Americans.
Gardiner also offers a chapter on biological controls, including a list of native plants that can be used to create a habitat that attracts natural predators. Another chapter describes how to monitor and collect good garden bugs.
With the right balance of plant-feeding herbivores and natural enemies, you can create a sustainable garden at home, she writes. Gardeners can achieve this balance in part by applying biological control tactics, which range from releasing natural enemies to conserving those already present within your landscape.
As professor and Graduate Studies chair at Ohio State University, Gardiner’s research areas focus on the ecology and conservation value of vacant land in cities, identifying contributors to native lady beetle decline, and enhancing biological control in urban agroecosystems. With Good Garden Bugs, she shares her wealth of knowledge with a broad readership in an easy-to-follow and user-friendly reference book.
Gillian Scott (11/8/19)
