The longest running study of insect biomass in the world suggests it is twice as large in Great Britain as it was in the 1960s, but has been declining since the 1980s
Source:
https://www.newscientist.com/article/2227154-insect-biomass-in-britain-falling-but-may-still-be-double-1960s-level/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home