USDA-ARS, Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, TX.
Department of Science, Schreiner University, 2100 Memorial Blvd, Kerrville, TX.
J Med Entomol. 2020 Sep 7;57(5):1575-1581. doi: 10.1093/jme/tjaa082.
With increasing development of resistance to conventional synthetic acaricides in economically and medically important ixodid species, interest in finding alternative control tactics has intensified. Laboratory bioassays were conducted, using the lone star tick, Amblyomma americanum (L.), as a model species, to assess the efficacy of a diatomaceous earth-based product, Deadzone, in comparison with a silica gel-based product, CimeXa. CimeXa is already known to be highly lethal against A. americanum larvae and nymphs. The two dust treatments were 100% effective against larvae and nymphs within 24 h after contact occurred by immersion in dry dusts and after crawling across a surface treated with the dry dusts. Contact by crawling on a dried aqueous film of the dusts, even at a concentration of 10%, was not as effective as exposure to the dusts in dry powder form. As has been demonstrated with CimeXa, it is likely that Deadzone will be capable of providing prophylactic protection of cattle from economically important one-host ixodids, such as the southern cattle fever tick, Rhipicephalus microplus (Canestrini), which vectors the causal agents of babesiosis. Diatomaceous earth can be stored indefinitely, will remain efficacious for as long as sufficient quantities remain on the substrate, it is a natural (organic) substance, and it might be amenable for limited use in environmentally protected habitats.
随着经济上和医学上重要的硬蜱物种对传统合成杀蜱剂的抗药性不断增加，寻找替代控制策略的兴趣日益浓厚。使用孤星蜱（Amblyomma americanum）作为模式物种进行了实验室生物测定，以评估硅藻土基产品 Deadzone 与硅胶基产品 CimeXa 的功效。已知 CimeXa 对美洲孤星蜱的幼虫和若虫具有高度致死性。两种粉尘处理方法在接触干燥粉尘后 24 小时内，通过浸泡在干燥粉尘中和在处理过的干燥粉尘表面爬行，对幼虫和若虫 100%有效。即使在 10%的浓度下，在干燥粉尘的水膜上爬行接触也不如以干粉形式暴露于粉尘有效。与 CimeXa 一样，Deadzone 很可能能够为牛提供经济上重要的一宿主硬蜱（如传播巴贝斯虫病病原体的南方牛热蜱 Rhipicephalus microplus（Canestrini））的预防保护。硅藻土可以无限期储存，只要在基质上保留足够的量，它就会保持有效，它是一种天然（有机）物质，并且可能适用于有限的环境敏感栖息地使用。
