For a long time, many of us have viewed insects as nuisances that need to be stamped out and eradicated. However, this view cannot be further from the truth. Insects are a crucial part of the natural world, with our wellbeing dependent on them. Now, we risk an unprecedented extinction event when it comes to insects, with 41 percent of the 1 million known species at risk.
In a report titled Insect Declines and Why They Matter, Professor Dave Goulson described the dire situation, with a particular focus on the United Kingdom. Since 1850, 23 bee and flower-visiting wasp species have gone extinct in the UK. This has consequences for our food supply, given that three-quarters of all crops grown by humans require pollination by insects. This service amounts to a worth between $235 and $577 billion annually worldwide.
“And it’s not just our wild bees and pollinators that are declining – these trends are mirrored across a great many of other invertebrate species. Of serious concern is the little we know about the fate of many of the more obscure invertebrates that are also crucial to healthy ecosystems,” Goulson, a professor of Biology at the University of Sussex, said in a statement.
“Insects make up the bulk of known species on earth and are integral to the functioning of terrestrial and freshwater ecosystems, performing vital roles such as pollination, seed dispersal and nutrient cycling. They are also food for numerous larger animals, including birds, bats, fish, amphibians and lizards. If we don’t stop the decline of our insects there will be profound consequences for all life on earth.”
"Wider countryside" butterflies have declined by 46 percent in the UK between 1976 and 2017, with that figure rising to 77 percent for specialist butterflies. There has also been a decline in bird populations, likely as a consequence of the dwindling number of insects. In the UK, the population of spotted flycatchers fell by 93 percent between 1967 and 2016. Similar numbers for nightingale (93 percent) and grey partridges (92 percent) were observed. The red-backed shrike, a common European bird, went extinct in the UK in the 1990s.
Goulson noted that “the main causes of decline include habitat loss and fragmentation, and the overuse of pesticides. Wild insects are routinely exposed to complex cocktails of toxins which can cause either death or disorientation and weakened immune and digestive systems.”
The report was commission by an alliance of wildlife trusts in the South West of England. While its focus is the UK, the picture painted is being seen all over the world. A recent Nature paper suggested that insect collapse will be even worse than previously feared.
"The consequences are clear; if insect declines are not halted, terrestrial and freshwater ecosystems will collapse, with profound consequences for human wellbeing," notes the report.