John is Professor of Biological Chemistry with particular interests in chemical ecology involving chemically mediated interactions between various organisms including pests attacking plants and animals.

John’s contributions to the field of chemical ecology have been acknowledged with the 1995 Rank Prize for Nutrition and Crop Husbandry, election to Fellowship of the Royal Society in 1996, election to Membership of the Deutsche Akademie der Naturforscher Leopoldina in 2001 and received the International Society of Chemical Ecology Medal in 2002. John was appointed to CBE for Services to Biological Chemistry in 2004.

In 2008 he was jointly awarded the Wolf Foundation Prize in Agriculture. He presented the Royal Society’s premier lecture in the biological sciences, the Croonian Prize Lecture in 2008, and the Cornell University Lecture in 2009. He was awarded the International Congress of Entomology Certificate of Distinction at the XXIV International Congress of Entomology held in Korea, August 2012. He was elected International Member of the National Academy of Sciences in 2014. He became President of the Royal Entomological Society in 2014 and in August 2017 gave the Sterling B Hendricks Memorial Prize Lecture at the 254th Meeting of the American Chemical Society, Washington DC. In 2020, John was elected Fellow of the Learned Society of Wales.