part_of adult subostial space adult vestibulum In argasid ticks, a enclosed area near the pedicels and connected to the subostial space. The roof of the vestibulum isflexible and can be everted or inverted, thereby controlling gaseous pressure into the tracheal trunks. In Exp. Appl. Acarology:14:151-163. TADS:0000351 TADS:0000351 default_namespace