The holotrichous setation for the prodorsumprodorsum:
the dorsal surface of the propodosoma.
of acariform mites is 6 pairs of setae (including trichobothriatrichobothrium:
(pl. trichobothria) (= bothridial sensillum) an often elaborately modified seta set in a cup-like base; forms include filiform, ciliate, pectinate or variously thickened or clubbed (bat-like to globose or capitate).
). Any additional on the prodorsumprodorsum:
the dorsal surface of the propodosoma.
is considered hypertrichy—a rare condition. If any of the basalbasal:
towards the base of a structure; on a limb, towards the insertion on the body.
6 pairs of setae are missing, then the condition is called hypotrichy. Since the assignment of designations to prodorsal setaeprodorsal setae:
the setae on the prodorsum of acariform mites. Two competing chaetotactic systems are used for designations: the Rostral-lamellar and Vertical-scapular systems. 
is somewhat arbitrary (hypothetical segments have not been identified), if 6 setae are present on the prodorsumprodorsum:
the dorsal surface of the propodosoma.
they are assumed to represent the holotrichous homologues.
Author: David E. Walter
Content last updated Sept. 2006, unless indicated otherwise
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