Field evaluation of Beauveria bassiana (Balsamo) Vuillemin isolates for the biocontrol of Rhipicephalus microplus (Canestrini) ticks on cattle

An insight into control strategies against bovine tropical tick (Rhipicephalus microplus) in context to acaricide resistance

The monoxenous Ixodid tick Rhipicephalus microplus is an economically important pest infesting cattle populations worldwide. Apart from being a vector of various diseases, they cause substantial production losses. The control against this tick is mostly through chemical acaricides, which have been undermined by problems of resistance as well as toxic residues in the environment and living beings. In spite of the development of two commercial vaccines against the tick way back in the 1990s, the anticipated results were not recorded in field conditions. The search for vaccine antigens has led to the identification of subolesin, serpins, lipocains and proteoses showing protective immune response. The efficacy of these candidate antigens is mostly assessed by the mortality of adult and larval stages and effect on reproductive performance. Similarly, the use of plant extracts, nano encapsulation of plant extracts and entomopathogenic fungi have been widely subjected to in vitro and in vivo trials to offer a cost-effective and green solution to tick infestation. In recent years, the use of modern technologies like RNA interference, in silico docking and CRISPR technology have accelerated the identification of potent antigens and active fractions of plant extracts. Integrated tick management is a good option for the eradication of R. microplus. However, the integration of chemical and non-chemical control strategies still remains a challenge. The present review article is focused on the ongoing and emerging control strategies against the tick that will help researchers evolve a sustainable solution against R. microplus infestation.

Entomopathogenic Fungi as Alternatives to Chemical Acaricides: Challenges, Opportunities and Prospects for Sustainable Tick Control

Entomopathogenic fungi (EPFs) can infect and kill a diverse range of arthropods, including ticks (Acari: Ixodidae) that can transmit various diseases to animals and humans. Consequently, the use of EPFs as a biocontrol method for managing tick populations has been explored as an alternative to chemical acaricides, which may have harmful effects on the environment and non-target species. This review summarizes studies conducted on EPFs for tick control between 1998 and 2024, identifying 9 different EPF species that have been used against 15 different species of ticks. One of the most well-known and widely researched EPFs used against ticks is Metarhizium anisopliae, a fungus known for its ability to infect and kill various arthropods. When applied to tick-infested areas, M. anisopliae spores attach to the tick's cuticle, germinate, and penetrate through the cuticle, leading to the eventual death of the tick due to the fungal infection. Whilst a number of studies support the potential of this and other EPF species against ticks, this review suggests that limitations to their effective use may include factors such as heat, humidity, and ultraviolet light (UV-A and UV-B). This comprehensive review aims to provide an overview of the literature on the potential of EPFs in tick control, focusing on their mode of action, previous field successes/failures, advantages, potential applications, and prospects for future practical developments.

Microbial agents for the control of ticks Rhipicephalus microplus

Ticks are ectoparasites responsible for the transmission of various pathogens to vertebrates. They represent one of the major threats to livestock production worldwide due to their impact on the health, production and welfare of livestock destined for human consumption. The development of resistance to the main families of ixodicides used for their control has led to the search for new alternatives, where microbial control is an option. The use of microbial control agents against the tick Rhipicephalus microplus is reviewed in this paper. Bacteria such as Bacillus thuringiensis, Serratia marcescens and Staphylococcus spp. the nematodes Steinernema spp. and Heterorhabditis spp. as well as the fungi Metarhizium anisopliae and Beauveria bassiana are the most studied organisms for use as biological control agents against ticks. Laboratory, stable and field trials with free-living and parasitised ticks have shown that microbial agents can control both susceptible and ixodicide-resistant tick populations. However, multidisciplinary studies using novel tools like genomics, transcriptomics and proteomics should be carried out to understand the virulence factors which microbial agents use to induce pathogenesis and virulence in ticks. In addition, applied research will be carried out with the aim of improving techniques for large-scale application, as well as the improvement of cultivation, storage, formulation and application methods.