Insect Loss

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Much has been made of the insect Armageddon news this month – that the massive decline in insect life is overwhelmingly terrible for the world. Conservationists and entomologists have been warning about this for years but perhaps the extent of the decline has been so far unknown. New research, however, has found that three quarters of flying insects on German nature reserves have vanished in 25 years.

This is an obvious problem for the food chain: fewer insects means birds don’t get as much food, therefore fewer birds; fewer birds for mammals to feed on. And it’s not just the loss of a direct food resource for birds – insects are our pollinators, and many birds and mammals feed on flowers and plants. Without insects the entire ecosystem will collapse.

So what might have caused this worrying trend?

  • loss of wild habitats
  • use of pesticides
  • possibly climate change

The scientists involved were able to rule out weather and landscape changes as not having sufficient impact to explain the severe 75% decline.

The scientists have been using malaise traps since 1989 to trap and analyse insect numbers across 63 nature reserves in Germany; given that the landscape throughout the rest of Western Europe is pretty much the same, I think it’s safe to generalise these findings to Britain as well. Not only has the research captured a much larger range of insects than is normally studied in one research attempt, it was also carried out on nature reserves, which are protected areas.

Just to get your head around how catastrophic this decline is, bear in mind that insects have dominated and thrived on this earth for millennia – they are incredibly prolific and have been relentlessly successful. And human behaviour has caused a 75% decline in 25 years?!

The conclusion of this research – that declining insect numbers have and will have a devastating effect on ecosystems as a whole – has been demonstrated by other evidence. Spotted flycatchers, who feed primarily on flying insects, have declined by 95%. Grey partridges, which feed their chicks on insects, have all but vanished from the countryside. We know it’s true from last year’s State of Nature report, which found that in the past 50 years over 56% of species have declined and 15% are either extinct or nearly. We also know this instinctively through anecdote: see the windscreen phenomenon.

It’s not just agriculture, though I’m pretty convinced that the loss of hedgerows and flower borders means that farmland is virtually an ecological void. Yet everywhere you look, there is tidiness. What used to be front gardens are now paved over for cars.  Grass is cut on road verges and around cities as soon as it reaches your ankles – I wrote a post about this.

What can we do about it?

  • get over our cultural aversion to creepy insects
  • consider the importance of the minutiae of ecology
  • stop poisoning the land with pesticides on an industrial scale
  • make our gardens mini nature reserves
  • bang on and on about insects on your blog
  • teach your kids to appreciate insects
  • lobby your local council to stop mowing every patch of grass

 

 

On The Importance Of Insects

Insects are the most common of all animals on the planet, totally around 1.5 million types of insects – that’s three times more than any other animal population combined!

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They are especially important to all ecosystems because they serve two functions: to pollinate and to clean. Many of the foods we rely on are pollinated by insects, and insects also provide an efficient service in cleaning up decaying matter and decomposing animals.

Insects are also eaten by many species, including reptiles, amphibians, other insects, mammals and, of course, birds, so they are a substantial foundation in the food web that most species simply could not do without.

Since the 1950s, however, insect populations have been declining, and conservationists are particularly concerned about the falling numbers of bees, moths, and butterflies. The Bumblebee Conservation Trust suggests that this decline in bee populations is due to a combination of factors but mostly we look to the loss of wildflowers in the countryside and new agricultural techniques. They estimate that we have lost around 97% of flower-grassland since the 1930s, resulting in the extinction in the UK of two species of bees – so far. They also suggest that:

Through the pollination of many commercial crops such as tomatoes, peas, apples and strawberries, insects are estimated to contribute over £400 million per annum to the UK economy and €14.2 billion per annum to the EU economy.

A very important insect, then. But it’s not just bees that contribute to the UK economy; ladybirds, for example, eat aphids, which feed on farmers’ crops.

But those are the cute, fluffy, colourful bugs – what about the ugly bugs? Cockroaches are probably universally despised, yet the 5,000+ known species that do not inhabit urban areas provide a significant ecological service in forests by cleaning up indigestible leaf matter, and by being a food source to desert lizards and some endangered mammals. Mosquitoes, too, despite being potentially deadly to humans, are a vital food source to birds and mammals.

There are some excellent resources on the internet to learn about the valuable role of insects in all ecosystems:

National Insect Week

Amateur Entomologists’ Society

Insects.org

 

 

 

The Sixth Mass Extinction Event Is Definitely Underway

According to new international research conducted by the Stanford Woods Institute, human activity has prompted the beginning of the Sixth Mass Extinction event recorded on earth, threatening to wipe out hundreds of thousands of species, including humans.

Professor Paul Ehrlich offers what he claims to be a “conservative estimate” of species loss due to human behaviour, which he puts at 100 times faster than the background rate of extinction (a base rate of extinction if humans were absent.) The team deliberately underestimated their estimates because recording species loss is notoriously difficult, yet their statistics are all the more shocking for it.

A devastating mixture of habitat loss, climate change, pollution and overpopulation has led to an environmental disaster that scientists refer to as the Holocene extinction. It is expected that this extinction event will be as severe as the End-Crustaceous Mass Extinction, which wiped out the dinosaurs 65 million years ago. That was, of course, due to an asteroid collision; this mass extinction is entirely due to human behaviour.

International Union for Conservation of Nature chart showing species loss over the last century.

And why should we care that species are dying out while humans industrialize the planet? We need biodiversity: it pollinates and irrigates our crops, purifies our water, and produces our food. We are entirely dependent on biodiversity.