Murillo Amy C, Mullens Bradley A
Department of Entomology, University of California, Riverside, CA 92521 (
J Econ Entomol. 2016 Dec 1;109(6):2572-2579. doi: 10.1093/jee/tow165.
Northern fowl mite management on conventionally caged birds relies on synthetic pesticide sprays to wet the vent. Cage-free chickens cannot be effectively treated this way, and pesticide use is restricted in organic production. Dustbathing behavior is encouraged in newer production systems for increased hen welfare. Diatomaceous earth (DE) is an approved organic insecticide that can be mixed with sand in dustboxes, suppressing mites but not excluding them, and potentially allowing development of mite immunity. We tested two hypotheses: 1) that DE-filled dustboxes placed before northern fowl mite introduction (prophylactic use) prevents mite populations from reaching economically damaging thresholds, and 2) that bird exposure to low mite numbers allows for protective hen immunity to develop and suppress mites after dustboxes are removed. We also tested if different beak trimming techniques (a commercial practice) affect mite growth. Mites were introduced to birds after dustboxes were made available. Average mite densities in flocks remained below damaging levels while dustboxes were available. Average mite populations rebounded after dustbox removal (even though DE persisted in the environment) regardless of the timing of removal. Mite densities on birds where a traditional hot-blade beak trimming technique was used (trial 1) were high. Mite densities in trial 2, where a newer precision infra-red trimming was used, were lower. The newer infra-red trimming method resulted in nearly intact beaks, which were better for mite control by bird grooming behaviors. The combination of early dustbox use and infra-red beak trimming should allow producers to avoid most mite damage in cage-free flocks.
传统笼养家禽的北方禽螨防治依赖于合成农药喷雾来浸湿泄殖腔。散养的鸡不能用这种方式进行有效治疗，而且在有机生产中农药的使用受到限制。在新的生产系统中鼓励鸡进行沙浴行为以提高母鸡福利。硅藻土（DE）是一种经批准的有机杀虫剂，可与沙子混合放入沙浴箱中，能抑制螨虫但不能将其根除，并且有可能使螨虫产生免疫力。我们测试了两个假设：1）在引入北方禽螨之前放置装有硅藻土的沙浴箱（预防性使用）可防止螨虫数量达到造成经济损失的阈值；2）让鸡接触少量螨虫可使母鸡产生保护性免疫力，并在移除沙浴箱后抑制螨虫。我们还测试了不同的断喙技术（一种商业做法）是否会影响螨虫生长。在提供沙浴箱后将螨虫引入鸡群。在有沙浴箱期间，鸡群中的平均螨虫密度保持在造成损害水平以下。无论移除沙浴箱的时间如何，移除沙浴箱后平均螨虫数量都会反弹（尽管硅藻土仍存在于环境中）。采用传统热刀片断喙技术的鸡群（试验1）螨虫密度很高。在试验2中，采用更新的精确红外线断喙技术，螨虫密度较低。更新的红外线断喙方法使鸡喙几乎保持完整，这更有利于鸡通过梳理行为控制螨虫。早期使用沙浴箱和红外线断喙相结合应能使生产者避免散养家禽群受到大多数螨虫损害。
