Susceptibility of Amblyomma sculptum, Vector of Rickettsia rickettsii, Ticks from a National Park and an Experimental Farm to Different Synthetic Acaricides

Researchers report the first documented resistance to amitraz and tolerance to deltamethrin, chlorfenvinphos, and a combination of cypermethrin-chlorpyrifos-citronellal in Amblyomma sculptum ticks from an experimental farm in Goiás, Brazil. These ticks, vectors for Rickettsia rickettsii (the cause of spotted fever), showed significant differences in susceptibility compared to their counterparts from Emas National Park where no prior acaricide exposure had occurred. The study used immersion tests on larvae and nymphs with six synthetic acaricides, revealing resistance ratios (RR) that highlight the impact of long-term acaricide use on tick populations. This finding underscores the need for adaptive pest management strategies in both protected areas and agricultural settings to mitigate public health risks.

Cardoso, E. R. N., Carvalho, S. F., Dias, S. A., Santos, R. A., Tavares, M. A., Neves, L. C., Paula, W. V. d. F., Pádua, G. T., de Lima, N. J., Paludo, R. L. d. R., Silva, I. S., Bittencourt, R. B. M., dos Santos, G. C., Nascimento, F. G. d. J., de Paula, L. G. F., Dantas-Torres, F., Monteiro, C. M. D. O., & Krawczak, F. d. S. (2023). Susceptibility of Amblyomma sculptum, Vector of Rickettsia rickettsii, Ticks from a National Park and an Experimental Farm to Different Synthetic Acaricides. Pathogens, 12(11), 1304. https://doi.org/10.3390/pathogens12111304