[Physiology of ticks (Ixodida) in non-parasitic phase of life cycle]

Non-parasitic phase of ticks is the most critical period of their life cycle. During off host period the ticks must maintain the water homeostasis and must find a host for feeding. Body water homeostasis is one of the most important processes that influences tick survival in nature and transmission of pathogens. Structure of intergument, particularly the waxy lipids in the epicuticle, and structure of peritremes restrict the loss of water from tick body. The water losses may be compensated by uptake of water vapour from the atmosphere. The critical equilibrium humidity of tick species of Ixodidae family range from 70 to 96% r.h. During non-feeding period, behaviour of ticks contributes to the maintenance of body water. The ticks aviod the microhabitats where loss of water may be accelerated.