Weeks E N I, Allan S A, Gezan S A, Kaufman P E
Entomology and Nematology Department, University of Florida, Gainesville, FL, U.S.A.
USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL, U.S.A.
Med Vet Entomol. 2020 Jun;34(2):184-191. doi: 10.1111/mve.12426. Epub 2019 Dec 26.
Rhipicephalus sanguineus is a canine tick that infests dogs throughout the world and is frequently found in homes and dog kennels. Management of this tick species is complicated by the presence of resistance to commonly utilized acaricides. Fungal formulations could provide a valuable alternative tool for management and are especially relevant indoors where detrimental environmental effects on fungal spores are of less concern. Two commercially available fungal formulations, one containing Metarhizium anisopliae and the other containing Beauveria bassiana, were compared for time to death and sporulation in nymphal ticks exposed for 60 min in treated filter paper packets. Beauveria bassiana exposure killed ticks faster than M. anisopliae exposure and B. bassiana was more likely to sporulate on tick cadavers than M. anisopliae. To determine whether infected ticks could disseminate fungus to their conspecifics, ticks were marked and treated with fungus before being placed with untreated ticks. Fungus was successfully transmitted from treated to untreated ticks. Mortality of ticks exposed to B. bassiana-exposed conspecifics occurred sooner than for those exposed to M. anisopliae-exposed conspecifics, indicating faster dissemination in the former. Therefore, although both formulations resulted in decreased longevity of ticks compared with the controls, the B. bassiana formulation holds the most promise for direct or indirect application with respect to brown dog tick management.
血红扇头蜱是一种寄生于世界各地犬类的蜱虫，常见于家庭和犬舍。由于对常用杀螨剂产生抗性，这种蜱虫的防治变得复杂。真菌制剂可为蜱虫防治提供一种有价值的替代工具，尤其在室内使用时，其对真菌孢子的有害环境影响较小。比较了两种市售真菌制剂，一种含有绿僵菌，另一种含有球孢白僵菌，观察在经处理的滤纸包中暴露60分钟的若蜱的死亡时间和产孢情况。暴露于球孢白僵菌的蜱虫比暴露于绿僵菌的蜱虫死亡更快，并且球孢白僵菌比绿僵菌更有可能在蜱虫尸体上产孢。为了确定受感染的蜱虫是否能将真菌传播给同种个体，在将蜱虫标记并用真菌处理后，将其与未处理的蜱虫放在一起。真菌成功地从未处理的蜱虫传播到了处理过的蜱虫。暴露于球孢白僵菌感染的同种个体的蜱虫死亡率比暴露于绿僵菌感染的同种个体的蜱虫更早出现，这表明前者的传播速度更快。因此，尽管与对照组相比，两种制剂都导致蜱虫寿命缩短，但球孢白僵菌制剂在棕狗蜱的直接或间接防治方面最具前景。
