Local and landscape-scale conservation of beneficial predators in Columbia Basin Potato Crops

Biological control by naturally-occurring predatory insects and spiders is an ecologically friendly and sustainable approach to pest management. Biological control is often underutilized, however, in part because we know little about how to successfully conserve predators to maximize their impacts on pests. Here, in Washington potato fields, we investigated the effects of planting wildflower insectaries on predator populations in fields, and the effects of non-potato crops as source or sink habitats for predators across landscapes. Planting wildflower insectaries near center pivots increased predator abundance, particularly ground predators, although these effects did not extend over a large distance (< 50 m). Predator populations, however, were broadly influenced by variation in non-potato crops across landscapes. Predator abundance in potatoes increased with increasing acreage of two common crops, alfalfa and peas, within 2 miles of potatoes. Furthermore, alfalfa and pea crops did not increase pest populations. In contrast, pest populations increased (and predator populations were unaffected), as the acreage of corn and onion crops within 2 miles of potatoes increased. Thus, alfalfa and peas appeared to broadly promote predator abundance (but not pests), while corn and onions appeared to intensify pest populations without impacting predators. Our results suggest that landscape-level factors can have strong impacts on predator and pest populations in potatoes, and should be carefully considered within the context of integrated pest management programs.

Grant Information

  • Project ID: 081
  • Project Status: Complete




  1. Results of research were published in November issue of Potato Country magazine
  2. We expect to publish results of these studies in 2012 in peer-reviewed manuscripts
  3. Results from this research will be disseminated to growers and extension agents through the Potato IPM website (at potatoes.com, see above)

Additional Funds Leveraged

We have gotten $160K from the Washington State Potato Commission and the Washington State Commission on Pesticide Registration in support of this work (this funding was from 2010-2012). Our USDA-RAMP grant, which spans 2010-2013, was for a total of $2,048,490 million.;Preliminary data from this BioAg project were incorporated into successful grant proposal ($130,000) awarded to Crowder by the USDA AFRI Postdoctoral Fellows program. This grant will investigate how broad-scale variation in landscapes and climate affects populations of predators and pests on potato farms.