An Integrated Approach to Managing Fly Pests in Dairy Calf Greenhouses 2000
Project leaders: D. A. Rutz and P. E. Kaufman, Department of Entomology, and J. K. Waldron, NYS IPM Program, Cornell University, Ithaca, NY
House flies, Musca domestica, and stable flies, Stomoxys calcitrans, are both extremely important dairy cattle pests in New York. House flies transmit diseases and are annoying, while stable flies inflict a painful bite causing weight loss and discomfort to animals. Both of these flies have the potential to move from the farm to neighboring homes creating legal challenges and extremely poor community relations.
Large, plastic covered, half-hoop structures, resembling greenhouses used for holding large numbers of calves are beginning to replace individual calf hutches on New York dairy farms. The benefits of using these atructures are numerous (easier animal handling, healthier calves, and easier cleanup), however, there is also the potential for buildup of large numbers of fly pests. Until recently, we have not had the opportunity to critically evaluate the effectiveness of our dairy fly IPM program recommendations in these facilities. Additionally, this on-farm project enabled us to evaluate our fly management recommendations and provide us with a means to solicit grower feedback and suggestions in "real time."
Eight dairy farms with calf greenhouses were used in this study with three farms serving as control sites and five serving as IPM farms. Farms chosen for this study ranged in size from 200 to over 2,000 milking cows and were located in Tompkins, Cortland, Onondaga and Cayuga counties. Fly breeding areas were observed on every farm. Maternity and calf rearing facilities were the primary sources for breeding activity.
Dairy producer opinions of fly densities on their farms do not reflect the recommended spot card-based fly treatment guidelines. Producers determined that fly densities were high enough to warrant additional management practices spot card data estimated that densities were sufficiently low. Sticky cards and calf leg counts appear to reflect producer perceptions more closely than do spot cards.
Sticky traps removed 641,000 house flies and 91,000 stable flies from five dairies throughout the course of the study. IPM farms were less likely to use insecticides and when needed used more IPM-friendly materials than Control farms. As was expected, the sticky traps were not a "silver bullet" to fly management, but were an important component in an overall strategy. Cultural control continued to exert the single greatest impact on changes in fly populations. When producers (IPM and Control) disposed of refused water out-of-doors and cleaned wet areas below feed and water buckets, fly numbers dropped. We are considering additional IPM strategies for inclusion in the second year of this study.