Climate change triggering global collapse in insect numbers: Study

The new study, published in Nature, finds that climate-stressed farmland possesses only half the number of insects, on average, and 25 percent fewer insect species than areas of natural habitat.

• Any small creature with six jointed legs and a body divided into three parts namely head, thorax and abdomen is known as an ‘insect’.
• They have wings, two antennae and an exoskeleton. Ants, bees and flies are insects.
• ‘Entomology’is the scientific study of insects, a branch of zoology.
• There may be as many as 10 million species of insects including:
  • 3, 60,000 species of beetle
  • 1, 80,000 species of butterfly and moth
  • 1, 20,000 fly species
  • 1, 10,000 species of bees, wasps and ants
  • 82,000 true bug species (cicadas, aphids, mealy bugs, etc)
  • 20,000 species of grasshoppers
  • 5,000 dragonfly species
  • 2,000 praying mantis species
    

Key findings of the study:

• Study area: Some three-quarters of a million samples from around 6,000 sites worldwide were analysed in study, adding up to nearly 20,000 different species in all.
• Insect declines are greatest in farmland areas within tropical countries– where the combined effects of climate change and habitat loss are experienced most profoundly.

• The farmland sites possess only half the number of insects, on average, and more than 25 per cent fewer insect species.

• Throughout the world, farmland in climate-stressed areas where most nearby natural habitat has been removed has lost 63 per cent of its insects, on average, compared with as little as 7 per cent for farmland where the nearby natural habitat has been largely preserved.
• It is predicted that climate change will have a particularly big impact in the planet’s tropical regions.
• Temperatures in the tropics are naturally quite stable, so species aren’t used to coping with the fast changes in temperature we are seeing with climate change.

• Natural cleaner: Insects are critical to the future of our planet. They help to keep pest species under controland break down dead material to release nutrients into the soil.
• Key-pollinators: Flying insects are also key pollinators of many major food crops, including fruits, spices.
• Eighty-seven of the world’s major crops are thought to be fully or partially dependent on insect pollinators,of which most tend to be grown in the tropics.

• Cocoa, for example, is primarily pollinated by midges, a group of flies infamous for bedevilling camping trips in Scotland and other parts of the northern hemisphere.
• In fact, midges play a vital and under-appreciated role in pollinating the cocoa needed to make chocolate.

• Diversified role: Insects are important because of their diversity, ecological role, and influence on agriculture, human health, and natural resources.
• Biological foundation: Insects create the biological foundation for all terrestrial ecosystems.

• They cycle nutrients, pollinate plants, disperse seeds, maintain soil structure and fertility, control populations of other organisms, and provide a major food source for other taxa.

• Food security:Their services are vital for India’s food security.
• Pest control:Insects keep pests in check. For example-

• Ladybird preys on aphids that damage crops.
• Insects such as ladybird beetles, lacewings, parasite wasps, etc, control other insects, arthropods and vertebrates.

• Food source:Insects are also food sources for amphibians, reptiles, birds and mammals.
• Economic significance:Insects have economic importance as well. They provide honey, silk, wax and other products.

• Dual threats: Insects are facing an unprecedented threat due to the “twin horsemen” of climate change and habitat loss.
• Habitat loss: Habitat loss can add to the effects of climate change by limiting available shade, for example, leading to even warmer temperatures in these vulnerable areas.
• Light pollution:Light pollution threatens the insects’ survival.
• Others:

• Particulate Matter
• Land-use change
• Insecticides
• Invasive species 

• Loss of insect biodiversity could put these vital ecological functions at risk, threatening human livelihoods and food security in the process.

A world without the internet would be difficult but livable. The same can’t be said for a world without insects.