Alarm over decline in flying insects

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Image caption Losses of rare insects are well documented, but there is little research on bugs as a whole

It’s known as the windscreen phenomenon. When you stop your automobile after a drive, there seem to be far fewer squashed bugs than there used to be.

Scientists have long suspected that insects are in dramatic deterioration, but new evidence confirms this.

Research at more than 60 protected areas in Germany indicates flying insects have declined by more than 75% over nearly 30 years.

And the causes are unknown.

“This confirms what everybody’s been having as a gut feeling – the windscreen phenomenon where you squash fewer glitches as the decades go by, ” said Caspar Hallmann of Radboud University in The Netherlands.

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 climate, 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 blooms 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.

“We don’t know exactly what the causes are, ” said Hans de Kroon, also of Radboud University, who supervised the research.

The receiving was even more worrying given that it was happening in nature reserves, which are meant to protect insects and other living species, the researchers said.

”In the modern agricultural landscape, for insects it’s a hostile environment, it’s a desert, if not worse, ” said Dr de Kroon.

The loss of insects has far-reaching consequences for entire ecosystems.

Insects provide a food source for many birds, amphibians, at-bats and reptiles, while plants rely on bugs for pollination.

The decline is more severe than found in previous studies.

A survey of insects at four sites in the UK between 1973 and 2002 procure losses at one of the four sites only.

The research is published in the journal Plos One.

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