Comparative effectiveness of acaricides

Abstract

The use of chemicals is the main method of controlling ectoparasites around the world. In Ukraine, due to the lack of an effective system for controlling ixodid ticks, there is an annual increase in the number of tick-borne diseases. Prevention of tick bites is largely based on the use of chemical repellents and acaricides. The study was conducted in 2019 in the laboratory of parasitology of the Department of Infectious and Invasive Diseases FVMTT PDATU. The experiments used neonicotinoids – imidacloprid, phenyl pyrazole - fipronil, pyrethroid compounds – cyfluthrin, permethrin. In the first phase of the studies, acetone was used as a diluent, each acaricide was diluted to obtain a 1.0 % solution, after which 10-fold dilutions of each acaricide from 1:10 to 1:107 were prepared and the study was performed. In the second stage of research, the method of topical application of acetone solutions of different concentrations was used. Cyfluthrin caused 100 % death of ticks of D. reticulatus and I. ricinus within 24 hours at a dilution of up to 1:10.000. Statistical analysis showed that ticks of the two species were significantly more sensitive to cyfluthrin and permethrin than to fipronil and imidacloprid, based on LD50 values. According to the level of contact activity, which is determined by topical application and the estimated LD50, cyfluthrin against I. ricinus was the most active acaricide and LD50 was 0.33 ± 0.07. In relation to D. reticulatus, the LD50 of cyfluthrin was 0.51 ± 0.08. After contact with cyfluthrin, 40 % of I. ricinus ticks and 30 % of D. reticulatus ticks died within one hour, and after 24 hours all ticks were dead. Among the adult stages of ixodid ticks, males were more resistant to the drugs than females. Therefore, cyfluthrin is recommended for the controling of ticks, which ensures the death of mites after a short period of time.