Zhendong Huang, Guangfu Yu, Zhong Zhang, Ruiling Zhang
Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Taishan Medical University, Taian, 271016, Shandong, China.
School of Basic Medical Science, Taishan Medical University, Taian, 271016, Shandong, China.
Exp Appl Acarol. 2019 Jan;77(1):83-92. doi: 10.1007/s10493-018-0329-9. Epub 2018 Nov 28.
Haemaphysalis longicornis (Acari: Ixodidae) is an important vector tick that is widely distributed around the world. In many regions, this tick acts as vector of a wide range of pathogens to humans and animals, and its control is mainly based on the use of chemical pesticides. However, the occurrence of some adverse effects, such as tick resistance to pesticides and food and environmental contamination, are driving the need to develop more effective and environmentally sound approaches to control and prevent ticks. As an alternative control strategy, entomopathogenic fungi have been extensively used for the control of pests and cause high mortality in various ticks. In this study, we identified four isolates of Beauveria bassiana sensu lato from insects and investigated their pathogenicity against different developmental stages of H. longicornis (eggs, unfed larvae, unfed nymphs and engorged females). Phylogenetic analysis demonstrated that the four isolates of B. bassiana clustered into two clades. Four isolates showed different acaricidal qualities: the isolate from Cerambycidae (EF3) exhibited the highest pathogenicity to all developmental tick stages tested. High doses (1 × 10 conidia/ml) of the clade I fungi collected from Cryptotympana atrata fabricus (Cicadidae) (EF1), Cimicidae (EF2), and Boettcherisca peregrine (Sarcophagidae) (EF4) also showed virulence against H. longicornis, with high doses of the fungi application causing higher mortality than control group. Altogether, this study demonstrated that all four isolates of B. bassiana showed high virulence toward different developmental stages of H. longicornis, and therefore, they can be of potential use as biological control agents of ticks.
长角血蜱（蜱螨亚纲：硬蜱科）是一种重要的媒介蜱，广泛分布于世界各地。在许多地区，这种蜱作为多种病原体的传播媒介，可感染人类和动物，其防治主要依赖化学杀虫剂。然而，一些不良反应的出现，如蜱对杀虫剂产生抗性以及食品和环境污染等问题，促使人们需要开发更有效且环保的蜱虫防治方法。作为一种替代防治策略，昆虫病原真菌已被广泛用于害虫防治，并能使多种蜱虫产生高死亡率。在本研究中，我们从昆虫中鉴定出4株球孢白僵菌复合种分离株，并研究了它们对长角血蜱不同发育阶段（卵、未进食幼虫、未进食若虫和饱血雌虫）的致病性。系统发育分析表明，这4株球孢白僵菌分离株聚为两个进化枝。4株分离株表现出不同的杀螨特性：来自天牛科的分离株（EF3）对所有测试的蜱虫发育阶段均表现出最高致病性。从黑蚱蝉（蝉科）（EF1）、臭虫科（EF2）和棕尾别麻蝇（麻蝇科）（EF4）采集的进化枝I真菌的高剂量（1×10分生孢子/毫升）对长角血蜱也具有毒力，高剂量施用真菌导致的死亡率高于对照组。总之，本研究表明，所有4株球孢白僵菌分离株对长角血蜱的不同发育阶段均表现出高毒力，因此，它们有可能作为蜱虫的生物防治剂。
