The vast reduction in insect numbers is indicative of generally declining nature everywhere, from birds to elephants, and wildflowers to frogs and toads. There are exceptions, especially with larger and more charismatic species, including otters and peregrine falcons. Generally, though, the trend is downwards. Because all nature is connected the declines in different groups are connected. Thus, fewer insects means fewer insect-eating birds, such as swallows, swifts and skylarks.
A recent long-term study in the Krefeld area of Germany estimates that insects there have reduced by a staggering 80% since 1989, a mere 28 years ago. This follows decades of decline which probably started with the impacts of DDT in the middle of the 20 century, and was exacerbated by increasing use of other pesticides, even when DDT was banned. Today there are general environmental improvements (although not enough) in air and water quality, but habitat loss, the impacts of climate change and disruption of ecosystems are putting enormous pressure on populations of many species.
This is a really important issue for humans. Much as we like to think that we can control nature, in reality nature controls us. It may appear that agriculture and nature are separated, that all the elements of food production are under our control, but they are not. From tiny creatures in the soil, to pollinators, and insects, birds and mammals which feed on the species we call pests, we need healthy and thriving natural systems running in the background. We can construct giant combine harvesters, but they will be useless if the crops fail. For some reason this issue has no political leverage, it was, for instance, ignored in the general election campaign. The time may be coming when we will no longer be able to ignore it.
Source: Birmingham Post, 14 June 2017