Organic Broadcaster

Book shows how to boost beneficial insect populations on the farm

By Andrew Dunham, Grinnell Heritage Farm

My first introduction to the Xerces Society was at the MOSES Organic Farming Conference a few years ago when I attended an Organic University session with Eric Lee-Mader, who co-directs the Xerces Pollinator Program. The course made quite an impression on me and has directly impacted our farm in many ways.

As a result of what I learned, we have installed two beetle banks, added brush piles in the middle of a hedgerow in our hay field, managed cover crops to provide pollen, and planted pollinator gardens near our packing shed. If you are not familiar, the Xerces Society is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. The Xerces book, Attracting Native Pollinators, has proven to be very useful to us as we have added pollinator habitat. The Xerces Society’s new book, Farming with Native Beneficial Insects, furthers their mission by providing accessible information for farmers and land managers to increase the numbers of beneficial insects on our farms.

Understanding the ecology of a particular farm is one key to being able to manage it organically. One of the shortfalls in many integrated pest management plans is that much of the focus is just on pest insects and the damage they do to crops.

Farming with Native Beneficial Insects makes the case why beneficial insects should be a higher priority for farmers—organic and conventional alike. The argument is made that we should focus on the needs of our beneficial insect partners as much as we focus on the pest species.

The approach of using beneficial insects to control pests is known as conservation biocontrol; one of the most familiar examples is the use of purchased lady beetles to control aphids in greenhouses. Farming with Native Beneficial Insects, as the title implies, advocates for a more comprehensive approach to integrating beneficial insects into our pest control programs by providing the kind of habitat these insects require to thrive and do meaningful work on our farms. Many of these invertebrates are present in the environment and will populate favorable habitat on their own—all we need to do is provide the habitat. Numerous case studies and examples highlight the impact beneficial insects have in our agricultural landscapes.

Farming with Native Beneficial Insects provides practical information on how to improve beneficial insect habitat on our farms. The “how to” sections of the book provide clear instruction for getting started with different types of habitat, ranging from native field borders to hedgerows. There are numerous seed and species lists for the different types of habitat, with region-specific recommendations that make the book useful across the United States. These lists are presented clearly in tables for quick reference and are accompanied by color photographs of many of the flowers, trees, and shrubs listed. The different types of beneficial insect habitat are also well photographed, with many pictures taken during installation. If you are interested in adding a beneficial insect feature on your farm, this book is a great place to start looking for information. By following the installation photos and recommended plants, you could begin creating your own beetle bank as soon as the frost leaves the ground next spring.

Everything in agriculture needs at least a little nurturing, and beneficial insect habitat does require some maintenance, which the book explains. The beetle banks we installed on our farm did require weeding in the first few years. We have also float-mowed the beetle banks early in the season, because they are comprised of warm season bunch grasses which are late to grow in the spring, allowing some weed control without harming the beetles. We also have to be very careful about applying organically approved pesticides in adjacent fields so as to not harm the very insects we planted the habitat for. The book describes many common management methods, including burning, weeding, and disking.

Many beneficial insects are familiar to us as insect pest eaters, such as the praying mantids. Others may not appear to be beneficial, such as predatory stink bugs. Color pictures and descriptions in the section titled “Common Beneficial Insects and their Kin” add to the value of the publication by acting as a guide book, organized by families. This allows readers to narrow the identification, setting them up to better utilize help from experts at their local extension office.

A section titled “Plants for Conservation Biocontrol” also contains full color photographs and descriptions of many plants commonly used in beneficial insect habitat plantings. Fortunately many of the plants that provide good pollinator habitat also provide food and shelter for other beneficials.

Organic agriculture and native beneficials are a natural fit, as adding beneficial insect habitat is an extension of many of the things we already do in organic agriculture such as cover cropping, using buffer strips along conventional field boundaries, and building soils. There are many examples in the book that a farm of any scale or level of sophistication could implement to improve habitat.

Farming with Native Beneficial Insects belongs in every farmer’s library, as a reference and a guide for how to improve beneficial insect habitat on the farm. Fencerow-to-fencerow farming really limits possibilities for beneficial insects, but some simple adjustments, such as adding habitat diversity, flower diversity, and some undisturbed places on a property can truly make beneficial insects an integral part of a farming operation.

Andrew Dunham farms at Grinnell Heritage Farm in Grinnell, Iowa.

From the January | February 2015 Issue

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