The importance of gamma irradiations with caesium-137 for Hyalomma anatolicum anatolicum (Metastigmata, Ixodidae) control

In this study, male ticks belonging to the Hyalomma anatolicum anatolicum species were subjected to gamma radiation doses of 5, 10, 15, 20 and 50 Gy, emitted by a gamma-ray source of Caesium 137. In females that fed with these male ticks, proportional to the increase in radiation dose, the period of feeding was found to shorten. A decrease was demonstrated in the number of engorged female ticks, engorgement weights, number of laying ticks and number of eggs. The hatching period of larvae from eggs was found to increase despite the decrease in the number of hatched larvae. Moreover no larvae were observed to hatch from any of the eggs of female ticks treated with a radiation dose of 50 Gy. Similarly, proportional to the applied dose of radiation, rates of viability and activity were observed to decrease in male ticks. In conclusion, taking into consideration the feeding periods and fertility rates of female ticks as indicators of male activity, this study has demonstrated that in combating with H. anatolicum anatolicum, radiation may be successful and a radiation dose of 10 Gy is most favorable.