Deployment
In 1919, during the Russian Civil War, Glowworm, Cicala, Cockchafer, Cricket, Moth, and Mantis served on the Dvina River (northern Russia, in Arkhangelsk Oblast), fighting in support of White Russian forces. Glowworm's captain and some other crew members were killed when a nearby ammunition barge exploded. The crew of Cicala mutinied, as part of a wider wave of unrest in the Royal Navy, and five "ringleaders" were sentenced to death, later commuted to five years imprisonment.
Between the two world wars, the class were mainly used in the Far East and they were present during the Japanese invasion of China. In 1937, on the Yangtze river, the Japanese attacked Ladybird, firing on her from a shore battery. A US gunboat, USS Panay was also attacked, by Japanese aircraft, and sunk. Ladybird sailed the 20 miles to the scene of the sinking, took on board some of the Panay survivors and took them to Shanghai. Scarab and Cricket were off Nanking in 1937 as the Japanese started to bomb the city.
In 1939 the original two 6 inch Mk VII 45-calibre guns on Aphis and Ladybird were replaced by more modern and 30 inch longer 6-inch Mk XIII 50-calibre guns from the decommissioned HMS Agincourt.
At the start of World War II, three vessels, Cricket, Gnat, and Ladybird, were transferred to the Mediterranean Fleet's Inshore Squadron. They joined the monitor Terror and provided bombardment support for the 8th Army. Their shallow draught allowed them to act also as supply and landing vessels, able to close in to beaches.
In June 1943, Aphis took part in the bombardment of Pantelleria (Operation Corkscrew).
Read more about this topic: Insect Class Gunboat