Body Coverings

A few groups of mites have distinctive secretions, accumulations, or pelages (coverings of hair) that reliably differentiate them.  For example, although all mites secrete a thin waxy layer on the outside of their cuticle, some sejid and monogynaspid Mesostigmata (especially Uropodina) secrete a thick, often ornamented covering on the body and legs called a cerotegument.  Similarly, many oribatid mites produce a thick, ornamented cerotegument that fits their body like a glove.  Others (Brachypylina) carry the dorsal notogasteral remnants of the cuticle of previous instars as a single or multiple 'scalps' piled on their backs.

A few Mesostigmata (Monogynaspida) and oribatid mites (Mixonomata) secrete a cement layer to which bits of soil and detritus may adhere as a kind of additional layer of armor (or perhaps tactile or visual camouflage).  A similar, although less dense adherent layer of pollen, fungal spores and the like may be found on species of Fungitarsonemus (Prostigmata, Eleutherengonides), common inhabitants of leaves in tropical climates.

Finally, most mites have a fairly sparse array of setae (mechanoreceptors) on their bodies.  However, some have a dense, furry pelage (e.g. some Endeostigmata and Anystides) or a covering of large leaf-like or plate-like setae (e.g. some Endeostigmata, Enarthronotides, Brachypylina, and Eleutherengonides).  Some important parasites of bees (e.g. Tropilaelaps spp. in Monogynaspida) also have a dense covering of setae.