Four years ago I read about the benefits of building a beetle bank as part of my Master Gardener training. While they began in Great Britain, Gwendolyn Ellen and her colleagues at Oregon State University have been studying their effectiveness on organic farms here in the Willamette Valley for years. As an ag biodiversity proponent, anything I can do on my farm to encourage native pest predators naturally peaks my interest. And so I spent the last few years reading all the research papers I could find on beetle banks and the predaceous beetles that they get their name from.
Beetle banks are raised strips of land installed in the middle of crops that are planted with native bunch grasses and sometimes forbes, which provide
habitat for an assemblage of beetles that consume both crop pests and weed seeds. By elevating the beetle banks they drain faster than the surrounding crop field and heat up quicker in the spring which allows the beetles to go out into the fields and knock down pests before they become a problem. The number one target are those pesky slugs.
With the help of Marie Vicksta from the Yamhill Soil and Water Conservation District I was able to secure funding from the Oregon Water Enhancement Board to build a beetle bank across the family farms. Construction will begin in August after the crop is harvested and planting will happen over the next couple of years. Year one planting will include five native bunch grass species and year two will include a number of pollinator plants.
I have been collecting baseline data on the various species of ground beetles that I currently have on the farm and what time of year they are active. In this way I will be able to see if the beetle bank is successful in building up these beneficial insect populations. I believe it is critical to have a before and after shot of the process in order to evaluate the effectiveness of this integrated pest management tool.
Over the next few years I will be writing about the planning, building and maintenance of my beetle bank. I do not expect it to be the one and only solution to pest management on my farm. However I do think that it is one more habitat enhancement to add to an agroecosystem to reduce the need for pesticides. It is my belief that we need to increase biodiversity if we want to have any chance of maintaining ecological balance on farms.