Ticks serve as vectors of a wide range of infectious agents deleterious to humans and animals. Tick bite prevention is based to a large extent on the use of chemical repellents and acaricides. However, development of resistance in targeted ticks, environmental pollution, and contamination of livestock meat and milk are major concerns. Recently, metal, metal oxide and carbon nanoparticles, particularly those obtained through green fabrication routes, were found to be highly effective against a wide array of arthropod pests and vectors. We summarize current knowledge on the toxicity of nanoparticles against tick vectors of medical and veterinary importance. We also discuss the toxicity of products from botanical- and bacterial-based as well as classic chemical nanosynthesis routes, showing differences in bioactivity against ticks based on the products used for the fabrication of nanoparticles. Further research is needed, to validate the efficacy of nanoparticle-based acaricides in the field and clarify mechanisms of action of nanoparticles against ticks. From a technical point of view, the literature analyzed here showed little standardization of size and weight of tested ticks, a lack of uniform methods to assess toxicity and concerns related to data analysis. Finally, an important challenge for future research is the need for ecotoxicology studies to evaluate potential negative effects on non-target organisms and site contamination arising from nanoparticle-based treatments in close proximity of livestock and farmers.
The rapid spread of highly aggressive arboviruses, parasites, and bacteria along with the development of resistance in the pathogens and parasites, as well as in their arthropod vectors, represents a huge challenge in modern parasitology and tropical medicine. Eco-friendly vector control programs are crucial to fight, besides malaria, the spread of dengue, West Nile, chikungunya, and Zika virus, as well as other arboviruses such as St. Louis encephalitis and Japanese encephalitis. However, research efforts on the control of mosquito vectors are experiencing a serious lack of eco-friendly and highly effective pesticides, as well as the limited success of most biocontrol tools currently applied. Most importantly, a cooperative interface between the two disciplines is still lacking. To face this challenge, we have reviewed a wide number of promising results in the field of green-fabricated pesticides tested against mosquito vectors, outlining several examples of synergy with classic biological control tools. The non-target effects of green-fabricated nanopesticides, including acute toxicity, genotoxicity, and impact on behavioral traits of mosquito predators, have been critically discussed. In the final section, we have identified several key challenges at the interface between "green" nanotechnology and classic biological control, which deserve further research attention.