及瓜而代的英文是「as soon as the melons are ripe one will be relieved -- to be replaced from a job」
ji gua er dai
及:到。到明年瓜熟时派人接替。指任职期满由他人继任。
《左传·庄公八年》:“齐侯使连称,管至父戍葵丘。瓜时而往,曰:‘及瓜而代。’”