Why insects are so crucial to life on Earth | BBC Ideas

Summary

Insects are vital to Earth's ecosystems, comprising 70% of all species and playing crucial roles in pollination and food chains. However, they face significant threats, including habitat destruction, pollution, invasive species, and climate change, leading to alarming population declines. Studies show a dramatic decrease in insect numbers globally, with many species at risk of extinction. While individual efforts like rewilding gardens and reducing pesticide use are important, systemic changes in farming practices and more support for insect conservation are essential. Insects are the 'rivets' of our planet’s ecosystem—without them, the consequences could be catastrophic.

Takeaways

• 😀 Insects make up around 70% of all known species on Earth and their combined biomass is 16 times that of humans.
• 😀 300 million years ago, giant dragonflies with wingspans of 75 cm existed, showcasing the long history and evolution of insects.
• 😀 Insects play a crucial role in ecosystems, being food for numerous animals and essential for pollination, which affects 80% of wild plants and three-quarters of crops.
• 😀 Without insects, many human populations would struggle to survive due to their vital role in agriculture and the food chain.
• 😀 A 2020 study estimated that land-dwelling insect populations are declining by 9% per decade globally, signaling a concerning trend.
• 😀 Between 1989 and 2016, flying insect biomass in German nature reserves fell by 76%, demonstrating a significant population decline.
• 😀 Monarch butterfly populations in the U.S. have dropped by 80% this century, and butterfly species in the UK have seen a 42% decrease in geographic range since 1976.
• 😀 Invasive species like rats and light pollution are contributing factors to insect population loss, disrupting life cycles and habitats.
• 😀 Climate change is negatively affecting many insect species, with some, like mosquitoes and cockroaches, benefiting from warmer conditions, while others, like bumblebees, suffer.
• 😀 There is still hope for insect recovery if protected, as many threatened species have not gone extinct yet and could bounce back with conservation efforts.

Q & A

What is the significance of insects on Earth?

Insects make up around 70% of all known species on Earth, and their combined biomass is 16 times that of humans. They play a crucial role in ecosystems, acting as food for many animals and pollinators for wild plants and crops.

How were insects different millions of years ago?

300 million years ago, giant dragonflies with wingspans of 75 cm soared among tree ferns. Insects were much larger back then, likely due to the higher oxygen levels in Earth's atmosphere.

What percentage of wild plant species depend on insects for pollination?

Around 80% of the world's wild plant species rely on insects for pollination, which includes three-quarters of the plants we grow for food.

Why are insects important for food production?

Insects are vital for pollination, and without them, many crops we rely on for food would not be able to reproduce, leading to potential food shortages.

What signs indicate a decline in insect populations?

A 2020 study found that land-dwelling insects are declining by about 9% per decade. Studies, including one in Germany, revealed alarming drops in flying insect biomass, with a 76% decline in nature reserves between 1989 and 2016.

What are some specific examples of insect population decline?

In the United States, monarch butterfly populations have dropped by 80% this century, and in the UK, the geographic range of butterflies has contracted by 42% since 1976.

How do invasive species impact insect populations?

Invasive species can directly harm insect populations, as seen when rats ate the St Helena giant earwig to extinction and nearly wiped out New Zealand’s giant weta.

What role does light pollution play in insect decline?

Light pollution disrupts insect life cycles by attracting moths to their deaths and disorienting species like dung beetles, which use the Milky Way for navigation.

How is climate change affecting insect populations?

Climate change is expected to harm most insects, though some adaptable species, like mosquitoes and cockroaches, might benefit. Bumblebees, for example, are struggling with overheating as their range shifts due to warmer temperatures.

What actions can be taken to protect insects?

Rewilding gardens and balconies, planting wildflowers, reducing pesticide use, and supporting sustainable farming practices are key steps individuals and communities can take. However, broader government and consumer support for insect-friendly practices is also needed.