Local entomologists shine a light on moth communities: The value of amateur records in cataloguing long‐term change

Abstract Natural history collections are composed of both biological specimens and associated written records. Biological specimens are increasingly used to investigate long‐term environmental change; however, written records also contain valuable information that can be used in similar ways and can complement specimen data. In this study, we describe two new collections and written records (in the forms of diaries and field notes) donated to the University Museum of Zoology, Cambridge (UMZC), the first biological specimens and written records amalgamated by Gerald Maurice Haggett (1927–2019), containing the works of Reverend Cyril Alfred Drummond Ash (1856–1949) and Harold Edward (Ted) Hammond (1902–1963), and the second written records by Colin Smith (1927–1997). We describe the biological specimens in relation to the existing collection in UMZC, to identify collector bias and specialisations, and then use the written records as a case study to demonstrate ways that these can be used to quantify environmental change. This included analyses to investigate changes in macro‐moth phenology over an 82‐year period across the United Kingdom and species richness and abundance change over a 24‐year period in Cambridgeshire. Using the written records, we detected evidence of earlier macro‐moth emergence over time and local declines in species richness and abundance. Depositing the collections of these skilled and knowledgeable local entomologists, which represent decades of work, in a museum ensures that the wealth of data they contain can be preserved and used in ongoing research. With amateur collectors in decline, it is increasingly important to preserve these records for the study of long‐term change and to encourage future generations to continue to amass and share this information.