NAVAL MEDICAL RESEARCH UNIT NO 3 CAIRO (EGYPT) DEPT OF MEDICAL ZOOLOGY
A description is presented of the fasting H. asiaticum males and females behaviour in the desert area of Kara-Kum, depending upon their water balance. The ticks are active in the morning and evening hours with the temperature of the ground surface of 20-40C and relative humidity of 20-50. In the day time, when the temperature of the ground surface may go up as high as 70C they hide themselves in burrows, crevices and other shelters with more favorable microclimate. The temperature in the latter usually does not exceed 40C while relative humidity is very near the saturation point. The fasting ticks are distinguished by an extremely high resistance to drying out under low relative humidity. At 26C they manage to survive for over a month with relative humidity amounting to only 0-25. With the rise of temperature the transpiration rate goes up accordingly. The critical temperature of the epicuticle is in the proximity of 55C. While losing water by transpiration on the ground surface the fasting ticks succeed in re-establishing their water-balance during their stay in microbiotopes with high relative humidity. Author
Trans. of Meditsinskaya Parazitologiya i Parazitarnye Bolezni (USSR) v29 n3 p313-20 1960.