2.3 Predatory Insect Relationships

Native grasses provide habitat for other beneficial insects as well, such as ground beetles. Ground beetles are voracious predators. They prey on other invertebrates such as aphids, slugs, and grasshoppers, that can be pests on vegetable and row crops. For this reason, native grasses are being used in various agricultural schemes as a form of biological pest control.

In England, farmers have been using beetle banks since the 1970‘s as a way to reduce chemical inputs. Beetle banks are rows of elevated earthen embankments that have been planted to native grasses and sometimes wildflowers. Predatory beetles take shelter in these strips over the winter, and dispatch in the spring into the fields where they prey on crop pests. Beetle banks have begun to catch on in the United States largely in the Pacific Northwest (Mäder et al. 2014). They are not commonly used throughout the country as of yet. Organizations like the Xerces Society are teaming up with federal agencies to research and promote this and other biological pest control measures.