Fifth instar codling moth natural enemies in organic apple orchards

The codling moth (Cydia Pomonella [L.]) is a severe pest of apples and pears worldwide. Fifth-instar codling moth larvae are vulnerable to natural enemies when they leave the tree canopy and seek a location to pupate or overwinter. A variety of factors interact to determine the number of natural enemies in an apple orchard at any given time, making it difficult to predict their impact on pest management. However, general trends have been observed and these can be used to guide management decisions. For example, insect natural enemies are generally more abundant when apple growers practice certified organic management or use reduced-risk management approaches. Growers in these types of orchards might expect an increased contribution from these natural enemies as they plan their pest management strategies. Unfortunately, there is still a lack of data available for apple growers to incorporate natural enemies into their pest management decisions. To remedy this, we have spent several growing seasons assessing the potential impact that natural enemies have on fifth instar codling moth in organic orchards in Michigan using a combination of video observations, sentinel prey, and experimentation. We have identified a complex of natural enemies preying on codling moth fifth instar larvae as well as major factors affecting their effectiveness in apple orchards. I will present the key findings of this work and discuss its implications for future codling moth management and research.