John Hopkins. British Wildlife Oct 2019 Volume 32 No 1
This is a review of insect decline. The research was based on 73 studies of insect declines each covering a time period of 10 years or more.
- The rate of insect declined is twice that reported for mammals.
- About one third of insects are threatened with extinction in the countries studied.
- Rates of decline in aquatic species are higher than for terrestial species.
- Many insect communities are shifting towards species poor collections of generalists and pollution tolerant species are dominating many fresh waters.
- Not only specialists with narrow ecological requirements are being lost but also some once common generalists.
- The rate of decline for the UK was 60%, higher than the global rate of 41% and the 44% decline in Europe as a whole.
As well as pollination, insects also control pests, play a key role in decomposition , nutrient cycling, and soil aeration and are food for many other animals.
The largest driver of change was loss and conversion of habitats to intensive agriculture or development. The second most important factor is identified as pollution by synthetic pesticides and fertilisers, significantly more influential than climate change.
Hertfordshire County Council is taking action on verge cutting. Is this enough? What about other County Councils?
Roadside verges could become home to wildflowers and the pollinators that feed on them, after Hertfordshire County Council agreed to test a new approach to grass cutting along the county’s roads.
Around 70 roadside verges in rural areas will be cut in a different way to encourage the growth of wildflowers. These areas will be cut only once a year, between mid-July and mid-August, with the grass cuttings removed. This will allow for the growth, flowering and seeding of wildflowers, as well as preventing the verges from being dominated by more aggressive plant species. This will provide an ideal habitat for bees and other pollinating insects.
The new approach to grass cutting will start in 2020, although it will take at least two years before the first wildflowers appear. Some verges may appear overgrown or unmaintained in the first year, but this a natural part of the new habitat establishing itself.
This new approach will contribute to the Sustainable Hertfordshire strategy – the county council’s ambitious programme to improve sustainability in the county.
The verges that will be cut in this way have been identified using wildlife and ecology data. They are mostly areas that have a medium to high quality of vegetation and diversity of species, and so are most likely to successfully establish themselves as wildflower habitats.
For safety reasons, verges in urban areas, and around rural junctions and bends in the road, will continue to be cut in the same way as before.
Hertfordshire County Council cuts approximately 6,500,000 square meters of roadside verges. Hertfordshire County Council declared a climate emergency in July 2019 and has committed itself to developing an ambitious programme to improve sustainability in the county