Where Did the Bugs Go? More Than 75% Decrease in Total Flying Insect Biomass Over 27 Years

Insects play a crucial role in ecosystem functioning, pollinating 80 percent of wild plants and providing a food source for 60 percent of birds. Previous research has shown an overall pattern of decline in insect diversity and abundance, but has focused on single species or taxonomic groups, rather than monitoring insect biomass over an extensive period.

To gain a better understanding of the extent and underlying causes of insect decline, Hallmann and colleagues measured total flying insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany. They found that the average flying insect biomass declined 76% (up to 82% in midsummer) in just 27 years in these locations. Their results align with recently reported declines in vulnerable species such as butterflies, wild bees and moths, but also suggest a severe loss of total flying aerial biomass, suggesting that the entire flying insect community has been decimated over the last few decades.

This is a malaise trap in a nature protection area in Germany.

Credit: Hallmann et al (2017)