part of adult mesothoracic sensillum notal microchaeta APAst2 fly_anatomy.ontology FBbt:00004322 VFB:FBbt_00004322 A short sensory bristle of the notum (mesothoracic tergum ; FBbt:00004580). There are around 200 of these, all with a bristle pointing posterior to their socket. They are arranged into approximately parallel rows running anterior to posterior. notal sensillum trichodeum mesonotum trichoid sensillum