The monoecious ticks may reach up to 2 cm in length and are vectors of important pathogens (viruses, bacteria, rickettsiae, anaplasms,  protozoa, and helminths; Table 2), since they feed on the blood of their hosts. Unlike  vessel feeders (  Mosquitoes), tick mouthparts bring about more or less deep hollows in the host's skin, which become filled by blood of ruptured blood vessels (Fig. 1). Thus, the ticks are  pool feeders engorging (in some species for minutes, in others for up to days) large amounts of blood (several times their body weights). During feeding salivary secretions prevent blood coagulation. In some species (e.g., Ixodes spp., Dermacentorspp.) these injected substances are toxic and cause paralysis (tick paralysis), which may lead to death in man and animals. In general, all stages of the tick's life cycle (larvae with 6 legs, nymphs and adults with 8 legs) suck blood. The life cycle of...