insects and flowers

HMS Grasshopper: built by Yarrow Shipbuilders, Glasgow in 1939, operated in a gunboat squadron in Shanghai securing Chinese rivers until the Japanese invaded China when Grasshopper and Dragonfly were sent to Batavia when they were bombed on 14 February 1942.

Locust-class gunboats were shallow-draught river gunboats, deployed on rivers in China during WWII.  Judy's ship, HMS Grasshopper and sister ship HMS Dragonfly were both bombed in 1942  south of Singapore and are used now as dive sites.  
HMS Gnat was built in 1915, used on the Euphrates during WWI and then transferred to China in the 1920s where it remained until 1940 before going to the Mediterranean and being torpedoed in 1941.  Towed to Alexandria, Gnat was used as a fixed anti-aircraft platform and was scrapped in 1945.

Why these boats were named after insects is difficult to find out.  However there is a class of delightfully named Royal Navy ships — the Flower-class corvettes, such as HMS Buttercup, HMS Larkspur, Peony and Crocus, used in WWII as anti-submarine convoy escorts in the north Atlantic.  They were relatively slow, armed for anti-submarine operations and some had anti-aircraft weapons.  There were 225 of them, 80 of which were in the Royal Canadian Navy and not named after flowers but after Canadian towns and cities, such as HMCS Timmins, HMCS Quesnel, Calgary, Chilliwack and Orillia.  

HMS Chrysanthemum, built by Harland & Wolff, Belfast in 1940 Transferred on 26 January 1942 to the Free French Navy as Commandant Drogou. Returned to the RN in May 1947. Sold on 7 August 1947. Resold in 1948 as mercantile Terje 10. Resold in 23 May 1959 to Portugal as hydrographic survey vessel NRP Caravalho Araujo (A524) until 3 September 1975 when she was transfer to Angola's Navy.
Ships have inevitably desperate biographies: if not sunk during a war, they are traded away for more pedestrian and workaday lives: HMCS Battleford, built in 1940, was sold in 1946 to Venezuela and renamed the Libertad; HMCS New Westminster, built in 1941 in Victoria was sold in 1950 as mercantile Elisa, resold in 1952 as mercantile Portoviejo, resold again in 1954 as mercantile Azura and scrapped in 1966 in Tampa.  HMCS Nanaimo, built in Esquimalt in 1940, was sold in 1952 to the Netherlands where it became the whale catcher René W Vinke. In fact a lot of them, both from the RCN and the RN seem to have become whale catchers.  How horrible.