Strongly inhibits juvenile hormone biosynthesis. May act as a neurotransmitter or neuromodulator (By similarity). Expressed in the CNS and midgut but not in the ring gland, thoracic perisymapthetic organs (tPSO) or abdominal perisymapthetic organs (aPSO) (at protein level). Detected in larvae. Belongs to the allatostatin family.