The beginnings of a beetle bank: this installation is using dead wood as a foundation for a beetle bank., mimicing the conditions of a forrest floor - the natural habitat of many predatory beetles. Photo: Jarrod Fowler / Xerces

Beetle banks invite natural pest control into your fields. A beetle bank is a berm planted with native grasses and/or wildflowers which attracts and supports predaceous ground beetles and other beneficial insects. Decomposing wood may also be added to beetle banks to enhance the habitat opportunities for beetles and above-ground nesting bees. The predaceous beetles attracted to beetle banks are known to kill more than they can eat, providing heightened control of pests like slugs and potato beetles.  The beetles are mostly active at night, so you might not see their armies at work, but you can easily see the results: fewer crop pests. Beetle banks are typically planted within or around crops, as the predaceous beetles tend to forage only a limited distance from them. 

Beetle Bank Basics: this image from the East Multnomah Soil & Water Conservation District illustrates the basics of creating a beetle bank.
 

From the Field: At Grinnell Heritage Farm in Iowa, beetle banks are a key pest control strategy. In fact, since planting their two beetle banks the farmers haven’t had to apply any pesticides to control potato beetles, which used to be one of their major crop pests. Sighting the beetles and their excess kills has become a favorite pastime among field hands on the farm.

Where to plant: Within or around fields.

Services provided: Pest Control; Educational Resource.

Additional information:

Farming with Beneficial Insects: http://xerces.org/farming-with-native-beneficial-insects/
Oregon State University Integrated Plant Protection Center: http://www.ipmnet.org/Posters_and_Presentations/Creating_A_Beetle_Bank_2006.pdf
Tualitin Soil and Water Conservation District: http://www.swcd.net/news/beetle-banks/