Investigation of susceptibility levels to some acaricides of Rhipicephalus spp. populations in Antalya

Ticks (Acari: Ixodidae) are ectoparasite organisms feeding with blood on vertebrates such as mammals and birds. Ticks transmit many pathogens affecting their hosts and cause many diseases like Crimean–Congo Hemorrhagic Fever (CCHF), Lyme disease and Q fever. The most commonly used method in tick control studies due to their fast action is the use of chemicals which is harmful to humans and the environment. Many acaricides have been using intensely in recent years and ticks can develop resistance to these chemicals. With the effect of resistance problem, control of tick populations is becoming more difficult according to the past, so incidence of tick-borne diseases may increase. Although in our country there are studies on the efficacy of various acaricides against ticks, no resistance or susceptibility studies have been done yet. In this thesis, it was aimed to determine susceptibility and resistance levels of some pesticides commonly used in pest control on Rhipicephalus spp. populations from different districts of Antalya. A total of 500 ticks were collected from dogs and two tick species were identified; Rhipicephalus turanicus Pomerantsev and R. sanguineus Latreille. Larvae produced by engorged females were used in bioassays based on the larval packet test (LPT) method and susceptibility/resistance studies were performed for 14 populations. Because permethrin, fipronil and chlorpyriphos-methyl are widely used as active ingredient in pesticide formulations, they were preferred in this study. Because bioassays were performed on only one population of R. turanicus, only the median lethal dose (LD50) values of active ingredients were determined. For the R. sanguineus species, 13 populations were treated with the LPT method and the population with the lowest LD50 value was considered sensitive. The results obtained from LPT conducted with permethrin showed that levels of resistance measured varied from 2,52 to 52,09 for R. sanguineus. The most susceptible population for permethrin is Yeniköy (Döşemealtı) population. For fipronil, levels of resistance measured varied from 1,23 to 15,87 and Gaziler (Kepez) is the most sensitive population. The most susceptible population for chlorpyriphos-methyl is Gaziler (Kepez) population and resistance levels of other populations varied from 1,29 to 26,6. To prevent resistance development, the integrated pest management approach should be prioritized, and chemical control should be kept at the lowest level. This study is the first for our country and is expected to lead other studies. In order to obtain more effective results, studies involving different tick species, different active substances and more regions are required. It is also thought that further studies are needed to determine the resistance mechanism in the regions where resistance is detected.