During the First World War, "Cockchafer" was assigned to the defence of the south east coast of England, based at Brightlingsea. During the Russian Civil War, she served with some of her sister ships as part of the British intervention forces fighting in support of White Russian forces on the Dvina River from 1918–1919. On 17 January 1920, the Insect-class ships , "Cockchafer", , and set out from Chatham, England for China. "Cockchafer" was stationed on the Yangtze River where her duties were patrolling and protection of British nationals and interests in China.