Ticks are typically acarine in having hexapod (six legs) larvae, and octapod (eight legs) nymphs and adults. The legs are jointed and divided into seven segments: coxa, trochanter, femur, genu, tibia, tarsus and pretarsus.
The terminal pretarsus consists of a basal stalk, paired claws and a membraneous pulvillus. The pulvillus is absent in argasid ticks (Mehlhorn, 2001).
While the legs are primary ambulatory, they may be modified to serve other functions. The legs of Acari may be smooth or variously ornamented and usually possess a number of tactile and sensory hair (Krantz, 1978). On the dorsal surface of tarsus I, e.g., the Haller`s organ, a complex sensory structure is found.
- Krantz GW: A Manual of Acarology. 2nd edn., 1978, Oregon State Univ. Book Stores, Corvallis
- Mehlhorn H: Encyclopedic Reference of Parasitology. 2nd edn., 2001, Springer Verlag, Berlin