“Silent Earth: Averting the Insect Apocalypse” Dave Goulson, Aug 2021
In this book Professor Goulson examines the dramatic decline in insects, the vital services they perform, the potential causes and possible solutions.
Insects pollinate three quarters of our crops, recycle dung, leaves and corpses, keep the soil healthy and control pests. Birds and fish rely on insects for food. We cannot function without them yet their decline is estimated as 75% in the past 50 years.
A study of nature reserves in Germany from 1989 to 2016 recorded a 75% fall in weight of insects caught in traps. A 10 year grasslands study showed an average two-thirds loss of weight in the insects, spiders, woodlice etc. Common UK butterfly abundance fell by 46% in 40 years.
There is little worldwide systematic monitoring of insects but the decline of insect eating birds shows the trend. North American insect eating birds have declined by 40% in 47 years with swallows and swifts numbers falling by 70% in 20 years. Similar declines are shown in the very limited studies from Africa, Asia and South America. At what point will there be a catastrophic failure in our environment?
The book reviews causes of the insect decline, habitat loss and fragmentation, pesticides and herbicides, farming practices and climate change. Agricultural change is required to manage these problems plus a change in Western life style and eating choices. This book makes a major contribution to raising awareness.
A Bumblebee Conservation Trust report:-
“A population of the very rarely sighted Ruderal bumblebee (Bombus ruderatus) was discovered in Wales this week by staff from the Bumblebee Conservation Trust.
The Ruderal bumblebee is one of our largest bumblebee species, and is thought to be largely restricted to the south of England, after a considerable decline through the 20th century.
Earlier this week two staff from the Bumblebee Conservation Trust found a number of newly emerged Ruderal bumblebee queens foraging on foxglove near Brechfa in central Carmarthenshire…. “
The Guardian newspaper reports:- “The critical ability of wild bumblebees to keep their colonies at the right temperature is seriously damaged by the weedkiller glyphosate, research has revealed.
Glyphosate is the most widely used pesticide in history, intended to kill only plants. The harm to bumblebees – vital pollinators – was not identified in regulatory risk assessments, which only test whether a pesticide rapidly kills healthy, individual bees. However, the collective failure to regulate colony temperature could have a massive impact on its ability to produce the next generation, the scientists said….”
Article in the Conversation web site:-
“Plants are flowering about a month earlier in the UK due to climate change. That’s according scientists at the University of Cambridge, who recently analysed the first flowering dates of 406 species and found a link to warmer temperatures in spring….
The problem is that climate change may increase the chance of plants and pollinators becoming out of sync, with plants flowering too early in the year for the insects that pollinate them….
In evolutionary biology, this is known as a “temporal mismatch”. Insects that are used to a feasting on April-flowering plants may find themselves arriving a month late if warmer temperatures mean that the plants now flower in March…
If earlier flowering reduces pollination, that would in turn reduce reproductive success and crop yields. Pollinators themselves could also be at risk, since earlier flowering could lead to gaps in resources like pollen and nectar leaving bees to go hungry… “
Guardian newspaper report:-
“Solar parks could provide habitats for wildlife – and particularly bumblebees – to flourish, if managed in the right way, benefiting farmers and nature, new research suggests…..
If solar park owners were encouraged to use the land to sow wildflowers alongside the solar panels, they could become valuable habitats for pollinators, research from Lancaster University has found. Managing them in this way would boost bumblebee numbers beyond the borders of the parks, to about 1km (0.6 miles) away, benefiting farmers who rely on bees to pollinate their crops…. “
Guardian newspaper report:-
“In the past 18 months humans have become all too familiar with the term “social distancing”. But it turns out we are not the only ones to give our peers a wide berth when our health may be at risk: research suggests honeybees do it too.
By examining videos recorded inside the hives, the team found that when the hive is infested with mites, foraging bees – which tend to be older members of the colony – performed important dances to indicate the direction of food sources, such as the waggle dance, away from the centre of the colony where the young bees, the queen and brood cells are found….”
Report in the Guardian newspaper:- ” Almost half of Britain’s natural biodiversity has disappeared over the centuries, with farming and urban spread triggered by the industrial and agricultural revolutions being blamed as major factors for this loss.
Britain has lost more of its natural biodiversity than almost anywhere else in western Europe, the most of all the G7 nations and more than many other nations such as China,
The world’s overall biodiversity intactness is estimated at 75%, which is significantly lower than the 90% average considered to be a safe limit for ensuring the planet does not tip into an ecological recession that could result in widespread starvation. On this scale, the UK’s index reading was 53%.”
- To pollinate 87% of plants. 75% crops need insect pollination.
- Recycle dung, leaves, corpses.
- Keep soils healthy.
- Control pests, though they can also be pests.
- Food for larger animals eg. fish. Crickets are 12 times more efficient than cows in converting vegetation into digestible body mass, produce little or no methane and use 55 times less water.
- Insects are in all food chains.
German nature reserve studies – over 27 years the insect biomass has dropped by 75%. Forest and grassland had a 40% drop over 10 years.
UK butterflies – over 41 years a 46% drop in common species numbers. 77% drop in rare species numbers.
US studies – 70% drop in insectivorous birds in 20 years.
Source:- Dave Goulson “Silent Earth” 2021
“Countries across Europe are exploiting a loophole to allow widespread continued use of bee-killing neonicotinoid pesticides, two years after the EU introduced a landmark ban on their use.
The EU agreed a ban on all outdoor uses of the neonicotinoid insecticides clothianidin, imidacloprid, and thiamethoxam on 27 April 2018, in order to protect bees.
However, an Unearthed investigation has found that in the two years since the ban was agreed, EU countries have issued at least 67 different “emergency authorisations” for outdoor use of these chemicals…”
Observer newspaper article:- “Insects have declined by 75% in the past 50 years – and the consequences may soon be catastrophic. Biologist Dave Goulson reveals the vital services they perform … “