Integrating Bats into Organic Pest Managment

by Steve Tennes (Country Mill Farms)

Organic farming involves creating a system approach that is in harmony with Mother Nature.  Organic farmers must determine what the natural predator is of any harmful insect in order to keep its population in balance.  Across several commodities, the moth order of insects are extremely harmful as internal feeders of crops like corn, apples, pears, peaches, oranges, and even nuts.  Specific species of bats need these moths as part of their diet.  Unfortunately, bat populations continue to decline due to a number of negative human influences. Codling moth is the most destructive fruit pest for apples and pears across the United States and Canada.  Bats can potentially act as a natural predator that could reduce codling moth populations.  Targeting adult flying moths with bats in conjunction with targeting earlier life stages of the moths with existing organically approved viruses and nematodes will establish a comprehensive system approach to manage these pests.  This research project will monitor the current level of bat activity at seven apple orchards.   Furthermore, the composition of specific bat species’ diet will be determined. The number of individual bats at an orchard can be potentially influenced by variables such as the distance from the application of synthetic insecticide, an open water source, a summer habitat and hibernacula (overwintering sites) suitable for that specific species.  Building upon existing bat research, this three year fruit project will determine the species of bats that are present on project farms, the composition of their diets, their pest management contribution and the best location for artificial bat habitat.   This information will be used to develop a procedural model that organic farmers can follow in order to increase the bat populations on their individual farms. 

OBC assisted in this project by mounting 28 triple-chamber bat houses at the seven apple orchards (organic and traditional).  The bat houses were erected in early April 2010.  Two bat houses were painted black and mounted back to back on each 4x6 post.  Each farm received four bat houses.  The farmers will monitor the bat houses for occupancy.  Once bats find the bat houses, OBC will assist in species identification and guano collection.  The guano will be sent to a laboratory to determine the species of insects the bats had eaten.  Further updates will be forthcoming.  

© 2012 Organization for Bat Conservation