Insect-class gunboat

The Insect class gunboats (or large China gunboats ) were a class of small, but well-armed Royal Navy ships designed for use in shallow rivers or inshore. They were intended for use on the Danube (the name was to disguise their function). The first four ships—Gnat, Mantis, Moth and Tarantula—were actually first employed during the World War I Mesopotamian Campaign on the Euphrates and Tigris rivers.

The ships were designed to operate in shallow fast-flowing rivers, with a shallow draught and a good turn of speed to counter river flow. They were fitted with two reciprocating (VTE) engines operating two propeller shafts to offer some redundancy. The propellers were housed in tunnels to minimise the operating draught.

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 get close-in to beaches.

In June 1943, Aphis took part in the bombardment of Pantelleria (Operation Corkscrew).

Ships

 * Aphis: scrapped Singapore, 1947
 * Bee: flagship of Rear Admiral, Yangtze (RAY), sold in March 1939.
 * Cicala: sunk by Japanese bombs on 21 December 1941.
 * Cockchafer: sold for scrap in 1949, the last surviving member of the class.
 * Cricket: heavily damaged by bombs on 29 June 1941; reportedly scrapped 1944; report false as sunk off Cyprus 1944.
 * Glowworm: scrapped September 1928.
 * Gnat: Damaged by U-boat, declared total loss, and then used as anti-aircraft platform. Scrapped 1946
 * Ladybird: sunk on 12 May 1941 off Tobruk during World War II, then used as an anti-aircraft position
 * Mantis: sold in January 1940 and subsequently scrapped.
 * Moth: captured by the Japanese and renamed Suma, sunk by mines in Yangtze River on 19 March 1945.
 * Scarab: scrapped in 1948.
 * Tarantula briefly flagship of the British Pacific Fleet, expended as a target 1946