part of attached to adult thoracic segment adult thoracic spiracle adult somatic muscle of thorax spiracular occlusor muscle occlusor muscle of adult thoracic spiracle 2022-07-05T13:30:44Z A muscle that functions in closing an adult thoracic spiracle. These muscles attach the rim (peritreme) of spiracle and to the adjacent body wall. Their contraction serves to bring the two lips of the spiracle together. fly_anatomy.ontology FBbt:00059066