[The action of carbon dioxide gas in high concentrations on ixodid ticks]

The ticks Ixodes persulcatus, Dermacentor reticulatus, D. marginatus were affected by 50, 70, 80 and 90% CO2 at 18 to 26 degrees. The higher the gas concentration and the lower the temperature, the quicker and the deeper was anesthesia. Additional tests have shown that response to CO2 depends on the water balance level determining the position of atrial valves. The response of some individuals to CO2 can change depending on the tick state during the experiment.