Palps - pedipalps

The capitulum of mites is comprised of two limb-bearing segments, the cheliceral and the pedipalpal.  Chelicerae have a maximum of three segments, but in the most primitive mites the palps retain up to six free segments (the basal segment, the palpcoxae, are always fused medially to form the subcapitulum or, when united dorsally as well, the basis capitulum).  The most distal segment, the palp-apotele (or claws) is present only in Parasitiformes and claw-like only in Opilioacarida.  In Holothyrida and Mesostigmata, the apotele is expressed at the base of the palptarsus as a 2-3 (rarely 4) tined structure.  The palp-apotele is absent in all Acariformes and in ticks (Ixodida).

The various reductions in the number of free segments is useful in distinguishing various groups of mites.  For example, most traditional oribatid mites have 5-free segments, but Astigmatina usually have only 2-free segments.

The thumb-claw process, i.e. a large distal claw on the palptibia that is opposed to a thumb-like palptarsus and acts like a pincer, is present in many Prostigmata (and an analogous structure in a few oribatid mites).

In some Eupodides (Bdelloidea) the palps are antenna-like and elbowed (geniculate) or raptorial (also in some water mites in the Anystides).  And in spider mites the palps may bear a distinct spinneret.