4-VA released from gregarious male locusts can significantly accelerate the ovary development of females with less-developed ovaries (approximately before post adult eclosion [PAE] 4 days) but not well-developed ovaries (after PAE 4 days). Mechanistically, after recognition by Or35 expressed in antennae, 4-VA promoted juvenile hormone (JH) synthesis in the CC and vitellogenesis in the fat body, thus accelerating female sexual maturation. The time-dependent stimulatory effects of 4-VA on ovary development finally led to the synchrony of female sexual maturation. CC-CA, corpora cardiaca and corpora allata; FB, fat body.