May act as a neurotransmitter or neuromodulator. In larvae, expressed in the CNS and midgut but not in the ring gland, thoracic perisymapthetic organs (tPSO) or abdominal perisymapthetic organs (aPSO) (at protein level). In adults, expressed in the corpora cardiaca, corpora allata, brain and the thoracic-abdominal ganglion (at protein level). Detected in larvae and adults. Belongs to the allatostatin family.