The subesophageal ganglion of insects is composed of three pairs of fused ganglia. It controls the mouthparts, the salivary glands and certain muscles.
It is also formed due to fusion of mandibular, maxillary and labium ganglia. The subesophageal ganglion sits beneath the esophagus. It is connected to the supraesophageal ganglion, which sits above the esophagus.