The State of Britain’s Larger Moths 2021 report is now available.
This new report summarises current knowledge of the state of Britain’s c.900 species of larger moths, presenting analyses of long-term change based on millions of records gathered through the Rothamsted Insect Survey (RIS) and National Moth Recording Scheme (NMRS).
- The total abundance of larger moths caught in the RIS light-trap network in Britain decreased by 33% over 50 years (1968–2017). Losses were greater in the southern half of Britain (39% decrease) than in the northern half (22%).
- Long-term abundance trends were calculated for 427 species of which 41% (175 species) had decreased and only 10% (42 species) increased, with the remaining 49% (210 species) having trends that did not show statistically significant change. Thus, four times as many moth species decreased in abundance than increased.
- Distribution trends revealed a different picture. Of 511 larger moth species for which long-term trends could be calculated from NMRS data, 32% (165 species) decreased in distribution and 37% (187 species) increased, while 31% (159 species) had non-significant trends. More moth species increased in distribution than declined.
- The decline of moths and other insects, both in Britain and elsewhere, is clear and demands an urgent response. We do not need to wait for robust global trends or scientific proof of causes of change. The existing evidence is compelling and clear policy pathways have already been identified; we can and should act now. In Britain, expanding, restoring, connecting and creating habitats that support rich arrays of moths and other wildlife, that improve human wellbeing and that deliver ecosystem services such as carbon storage, flood prevention and cleaner air, is the key to reversing moth declines and confronting the biodiversity and climate crises.