The Biggest Extinction Is Happening Under Your Nose

Image Courtesy: Science Alert

Insects are the stars of a global vanishing act. Despite an estimated 5.5 million species of insects, many are declining at a rapid rate, and even more becoming extinct. Over 40% of known insects are facing extinction in North America and Europe. In Australia it is estimated that 3 native insects or other invertebrate species are going extinct every week. Insect disappearances are only increasing with time, so why is this happening?

We currently live in the human-driven 6th mass extinction called the ‘Holocene’, where humans are driving the extinctions of species on Earth at an unprecedented rate. The main culprit behind the insects’ disappearance is human pollution. Pollution affects every part of insect lives, as it fundamentally changes the environment and conditions for insects to live in.

The most well-known pollution is through the use of insecticides. These harmful chemicals are often aimed at insects or pests which damage agriculture. Humans are using over double the pesticides compared to 1990, with 3.7 million tonnes used in 2022 according to the UN. Agricultural use of chemicals is the key player in the decline of insects worldwide. The main reason why these chemicals wreak havoc for insects is that most pesticides are not specific to insect species, and affect many other species in their crossfire. Chemical pollution of the environment contributes to climate change and increased temperatures. The temperature variance massively affects insects due to their small size and cold-blooded nature. Without being able to regulate their temperature, formerly hospitable locales suddenly become deadly.

Sound pollution also affects insects and is a major issue for environments across the globe. The rising adoption of cars and urban sprawl has contributed to 1 in 5 EU citizens being affected by noise pollution leading to approximately 12,000 premature deaths in humans. Insects require sounds to communicate and they are critical for mating rituals, finding food and reproducing. Insects like cicadas, grasshoppers and locusts rely heavily on minute vibrations which they are evolved to seek out for these tasks, which is being made more difficult. As human environments grow louder we will see the insect world go silent.

An increasingly global world brings a new risk that significantly impacts insects. Insects are able to use human transportation, such as freight ships, planes and cars and can become invasive species in environments far away. Insects are hyper-mobile thanks to humans with it only taking a single insect species to cause devastating effects on the local bugs. The effect of this can be catastrophic. In the UK, Asian hornets have invaded and are highly aggressive to our local pollinators. The threat is so serious that the Animal and Plant Health Agency have a hotline for the public to report sightings of the hornet. The reason why this migration is so devastating is that in native environments these insect invaders have predators and parasites that keep them in check, regulating ecosystems and ensuring that their populations become unsustainable in their native ecosystems. However, in a new environment, they are able to run rampant and feed off of the locals, outcompeting them and destroying their niche in the environment.

Insects suffer massively from a public image problem too. Unlike ' cuter ' animals, insects are not a widely sought-after target for global conservation efforts (aside from bees), and they struggle to get funding for their causes. Insects are often perceived as pests, despite their critical roles in our environment as pollinators, decomposers and food sources for other species. 

However, that does not mean all is lost yet. Insects have a larger diversity than all other animal groups combined boasting many species in a variety of environments. Certain insect species can cover for those that have gone extinct, and there are still many that can still flourish. However, with more and more species being lost due to human causes, the safeguards of redundancy that protect our food, our flowers and our environment are slowly being stripped away. The worry here is that if insect populations collapse, the effects will be felt by plants, animals and humans alike. If insects go extinct we may have to learn the hard way that it is the little things that make the world go round.