Introduction:

The world’s insects are hurtling down the path to extinction, threatening a “catastrophic collapse of nature’s ecosystems”, according to the first global scientific review. Butterflies and moths are among the worst hit.

Body:

Magnitude of the problem:

• Worldwide, a 2014 summary of global declines in biodiversity and abundance estimated a 45 percent drop in the abundance of invertebrates, most of which are insects.
• More than 40% of insect species are declining and a third are endangered, the analysis found.
• The rate of extinction is eight times faster than that of mammals, birds and reptiles.
• The total mass of insects is falling by a precipitous 2.5% a year, according to the best data available, suggesting they could vanish within a century.
• The 2.5% rate of annual loss over the last 25-30 years is “shocking”. “It is very rapid. In 10 years there will be a quarter less, in 50 years only half left and in 100 years you will have none.”
• the number of widespread butterfly species fell by 58% on farmed land in England between 2000 and 2009.
• The number of honeybee colonies in the US was 6 million in 1947, but 3.5 million have been lost since.
• There are more than 350,000 species of beetle and many are thought to have declined, especially dung beetles.
• a research team from the U.S. and Mexico reported a startling decline between 1976 and 2013 in the weight of insects and other arthropods collected at select sites in Puerto Rico.

Causes:

• Widespread use of insecticides is one obvious one. Industrial-scale, intensive agriculture is the one that is killing the ecosystems. New classes of insecticides introduced in the last 20 years, including neonicotinoids and fipronil, have been particularly damaging as they are used routinely and persist in the environment
• Habitat loss and degradation: Changing environmental conditions have led to a proliferation of tree-harming insects such as the mountain pine beetle in North America.
• Declines in or disappearance of plants or animals that specific insects depend on for food and shelter
• Displacement by non-native species: non-native species such as Japanese beetles in the U.S., Asian hornets in Europe and the polyphagous shot hole borer in South Africa tend to show rapid population rises as they invade new territories.
• Air, water and light pollution – nitrification due to fossil-fuel burning
• The global spread of insect diseases.
• Urbanization and Climate change due increasing global warming, human overpopulation and overconsumption. The rising temperatures due to climate change are thought to be a significant factor in the decline

Impacts:

• Insects are at the heart of every food web: One of the biggest impacts of insect loss is on the many birds, reptiles, amphibians and fish that eat insects. If this food source is taken away, all these animals starve to death.
• Pollination: they pollinate the large majority of plant species.
• keep the soil healthy
• Recycle nutrients: some of the insects are scavengers which help in decomposing the organic materials and recycle the nutrients
• Control pests: Pests are controlled as they are preyed upon by insects.

Way forward:

• Many scientists say, we need to get a better handle on what’s currently out there in terms of species and numbers so we have a baseline for measuring change and a notion of what might need protecting.
• Scientists are calling for developing a better sense of trends in abundance and diversity through studies that are repeated over time at the same location, resampling in areas where baselines were established decades ago.
• Conservationists are also calling for boosting awareness of the value of insects in the eyes of everyday people.
• Reduced usage of synthetic and chemical fertilizers, practice sustainable agricultural methods like organic farming, ZBNF etc.

Conclusion:

Insects are linchpins of the living world, carrying out numerous functions that make life possible. Love them or loathe them, we humans cannot survive without insects.