Wildlife

Alarm over decline in flying insects

Scientists have long suspected that insects are in dramatic decline, but new evidence confirms this. Research at more than 60 protected areas in Germany suggests flying insects have declined by more than 75% over almost 30 years. And the causes are unknown.

The study is based on measurements of the biomass of all insects trapped at 63 nature protection areas in Germany over 27 years since 1989. The data includes thousands of different insects, such as bees, butterflies and moths. Scientists say the dramatic decline was seen regardless of habitat, land use and the weather, leaving them at a loss to explain what was behind it. They stressed the importance of adopting measures known to be beneficial for insects, including strips of flowers around farmland and minimising the effects of intensive agriculture. And they said there was an urgent need to uncover the causes and extent of the decline in all airborne insects.

The loss of insects has far-reaching consequences for entire ecosystems. Insects provide a food source for many birds, amphibians, bats and reptiles, while plants rely on insects for pollination.