Efficacy of water-based botanical acaricide formulation applied in portable spray box against the fever tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae), infesting cattle

Authors: KLAFKE, GUILHERME - Desiderio Finamore Veterinary Research Institute (FEPAGRO); Thomas, Donald; Miller, Robert; Perez De Leon, Adalberto - Beto

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2021
Publication Date: 4/3/2021
Citation: Klafke, G., Thomas, D.B., Miller, R., Perez De Leon, A.A. 2021. Efficacy of water-based botanical acaricide formulation applied in portable spray box against the fever tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae), infesting cattle. Veterinary Parasitology. 12. Article 101721. https://doi.org/10.1016/j.ttbdis.2021.101721.
DOI: https://doi.org/10.1016/j.ttbdis.2021.101721

Interpretive Summary: Botanical oils provide an alternative to synthetic chemicals for the control of parasites such as ticks. They can be applied safely to pets and livestock with minimal risk of poisoning or unwanted environmental impacts. We tested a mixture containing essence of peppermint, geranium and rosemary, marketed under the name "Essentria," against the southern cattle fever tick, a major pest of cattle and a threat to the American livestock industry. One of the standard methods for controlling this pest involves dousing the cattle one at a time in a portable spray box with a solution containing the pesticide Coumaphos. For our experiment we compared the level of control obtained using Essentria at the manufacturers recommended dosage applied with the spray box, compared to the standard coumaphos and a check solution of pure water. We treated cattle infested with fever ticks. The result was that coumaphos gave 100% control, water gave no control, the Essentria gave 70% control. Based on these results we would not recommend the use of Essentria for fever tick control at this time. However, should Coumaphos be banned, or if the ticks develop resistance to coumaphos, Essentria might have some use.

Technical Abstract: Direct effects of ectoparasitism result in annual losses to livestock producers estimated to reach billions of dollars in tropical and subtropical parts of the world where the southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini, 1887), is established because this invasive pest is also a vector of pathogens causing bovine babesiosis and anaplasmosis. Reintroduction of R. microplus can be economically devastating for the cattle industry in the USA. Novel technologies are necessary to manage populations of R. microplus that are resistant to multiple classes of synthetic chemicals widely used as acaricides to control ticks infesting livestock, and to mitigate the environmental impact of these synthetic acaricides. Bioassays with a water-based formulation of the commercially available plant-derived, or botanical containing essential oils, acaricide Essentria®IC3 at 6.25% against a laboratory strain of R. microplus was 100% lethal against larvae, and 93.9% mortality was recorded against engorged female ticks. These results prompted documentation of efficacy on infested cattle using an acaricide delivery system mimicking field conditions, which is required to consider the use of a product by integrated tick management programs. Twelve tick naïve cattle were infested three times at weekly intervals and assigned randomly based on pre-treatment tick counts into three separate treatment groups: i) water (untreated control); ii) coumaphos 0.3% in water (positive control); and iii) Essentria®IC3 6.25% in water. Eighteen days after the first infestation, cattle were doused in a spray box and moved to individual stalls to collect tick data for calculation of treatment efficacy. Compared to the untreated group, coumaphos treatment was 100% efficacious by suppressing tick development completely. Overall efficacy of the 6.25% Essentria®IC3 water-based spray applied to infested cattle in the box was 70.1% against R. microplus. Whereas this application of Essentria®IC3 cannot be recommended to eradicate R. microplus, the 6.25% Essentria®IC3 water-based spray could be part of integrated tick management to control populations of R. microplus resistant to organophosphates like coumaphos and other classes of commercially available synthetic acaricides.