Size
normal adult body length about 3 mm; up to 30 mm when engorged with blood
Identification
There are soft ticks (Argasidae) and hard ticks (Ixodidae). Soft ticks have a leathery integument, no head plate, and the head is on the underside. Hard ticks have a hard plate above the head, and the head is directed forward.
(1) Young ticks may have have only three pairs of legs, whereas adults have four pairs.
Habitat
They wait on the tips of leaves and branches with forelegs stretched out, ready to attach to any animal that brushes past.
Food
External parasites of reptiles, birds, and mammals; larvae, nymphs, and adults feed on blood.
Life Cycle
Hard ticks have three distinct life stages. Larvae emerge from the egg having six legs. After obtaining a blood meal from a vertebrate host, they molt to the nymphal stage and acquire eight legs. Nymphs feed and molt to the next and final stage (the adult), which also has eight legs. After feeding once more, the adult female hard tick lays one batch of thousands of eggs and then dies. Only one blood meal is taken during each of the three life stages. The time to completion of the entire life cycle may vary from less than a year in tropical regions to over three years in cold climates, where certain stages may enter diapause until hosts are again available. Many hard ticks can go for several months without feeding if not unduly duressed by environmental conditions.
Remarks
This section is being reorganized per the
Acari Project.
There are two well established families of ticks, the Ixodidae (hard ticks), and Argasidae (soft ticks). Both are important vectors of disease-causing agents to humans and animals throughout the world. Ticks transmit the widest variety of pathogens of any blood-sucking arthropod, including bacteria, rickettsiae, protozoa, and viruses. Some human diseases of current interest in the United States caused by tick-borne pathogens include Lyme disease, ehrlichiosis, babesiosis, rocky mountain spotted fever, tularemia, and tick-borne relapsing fever.
