William Warren (entomologist)

William Warren (20 January 1839 in Cambridge – 18 October 1914 in Hemel Hempstead) was an English entomologist who specialised in Lepidoptera.

Warren was first educated at Oakham School, and subsequently graduated from the University of Cambridge, taking first-class classical honours in 1861. He then taught at Sedbergh School, Doncaster Grammar School (1866–1876) and Stubbington House School. He collected extensively in the British Isles, notably at Wicken Fen, with a special interest in Micro-lepidoptera. After giving up teaching in 1882, he lived in Cambridge and devoted himself fully to entomology, publishing around 40 papers on British moths between 1878 and 1889.

In 1887, he was the first to recognise Grapholita pallifrontana as a British species of micro-moth, a species which now has the English name the Liquorice Piercer and is of conservation concern. Later that year he successfully bred the moth and described its larvae. In 1888, he moved to Chelsea, London, where he worked as a professional entomologist on Pyralidae and Geometridae in the Natural History Museum. Later, by the intervention of Albert Günther, for the Natural History Museum at Tring, publishing over 80 more papers. Warren made collecting trips to the Punjab, Brazil and Japan. He was a Fellow of the Royal Entomological Society of London from 1886–1914.