part of ventral pharyngeal sense organ labial sensory organ Paired compound sense organ of the labial segment in the larval head, located on the floor of the atrium, anterior to the opening of the salivary duct (Campos-Ortega and Hartenstein, 1997). It is composed of 4 sensilla (Campos-Ortega and Hartenstein, 1997). Sensory neurons travel via the labial nerve and innervate area 2 of the embryonic/larval subesophageal ganglion (Colomb et al., 2007). Neurons of the ventral pharyngeal sense organ and labial organ form a large cluster flanking the salivary duct (Campos-Ortega and Hartenstein, 1997). hypophysis VFB:FBbt_00002719 hypophyse anteroventral group of pharyngeal sensilla ventral pharyngeal sensilla V1-V3 Python and Stocker, (2002) map VPS to V1-4 in Singh and Singh (1984), but V4 seems to far posterior (posterior to DPS), so might just be V1-3. FBbt:00002719 vps VPS labial sensory complex LiSO ventral pharyngeal sensilla labial sense organ lbso fly_anatomy.ontology external compound sense organ larval labial sensory complex embryonic/larval head sense organ