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.

Ecological importance of insects:

• Insects are critical to the future of our planet.
• They help to keep pest species under control and break down dead material to release nutrients into the soil.
• Flying insects are also key pollinators of many major food crops, including fruits, spices and — importantly for chocolate lovers – cocoa.
• Insects are important because of their diversity, ecological role, and influence on agriculture, human health, and natural resources.
• 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.
• Most major insect pests in agriculture are non-native species that have been introduced into a new ecosystem, usually without their natural biological control agents.
• Insects have evolved unique features in the animal world that are a surprise to experts in biomechanics and bioengineering because many are recent inventions of humans.
• Insects have been in competition with humans for the products of our labor ever since cultivation of soil began.
• 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.

Key findings of the study:

• Some three-quarters of a million samples from around 6,000 sites worldwide were analysed in our study, adding up to nearly 20,000 different species in all.
• Insects are facing an unprecedented threat due to the “twin horsemen” of climate change and 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.
• 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.