Hundreds of bug species face extinction and thousands more are critically endangered. Picture:
Hundreds of bug species face extinction and thousands more are critically endangered. Picture:

Death by a thousand cuts – Global threats to insect populations

By Dominic Naidoo Time of article published Sep 13, 2021

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There are an estimated 1.4 billion insects for each and every one of us. Ranging from tiny, microscopic bugs to gargantuan Goliath beetles and stick insects.

Currently, according to Guinness World Records, the world record for the longest insect is held by the stick insect species Phryganistria chinensis, which was discovered in China in 2016, with one specimen measuring 64 centimetres, well over half a meter in length.

Today, hundreds of bug species face extinction and thousands more are critically endangered.

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While there are insects such as roaches, ants and bed bugs that are hugely resilient to external changes, most creepy crawlies are quite sensitive to even minute changes in temperature, humidity and even light.

A few insects recently went extinct such as the Cascade funnel-web spider which was first described in 1926 and was officially declared extinct in 1995 due to urbanisation.

Cascade funnel-web spider. Picture: Craig Marriott/Facebook

The levuana moth of Fiji also went extinct - it was the target of an intense eradication campaign in the early 20th century due to its primary food source, coconuts, being one of the island nation's biggest exports.

This moth can no longer be found in Fiji, though some naturalists hope it still survives on other Pacific islands further west.

Approximately 99 percent of species that have walked the Earth are now extinct, having disappeared because of changes in the environment or the appearance of new ones, leading to a constant turnover. The rate of extinction, however, has never been as high as it is today.

What has happened to bring about such drastic changes to natural cycles? Humans happened.

EcoWatch, in a set of studies published in February 2019 and April 2020, as well as a roadmap released in January 2020 by 73 scientists, detailed ways in which we could turn the tide on the steady decline of insect populations.

As the new research explains, human stressors that experts have tied to bug declines include agricultural practices; chemical, light, and sound pollution; invasive species; land-use changes; nitrification; pesticides; and urbanisation.

Graphic: EcoWatch

Extracted from the graphic above published by EcoWatch, the below further explains how human activities are having an ongoing negative impact on global insect populations.

Interaction Disruption

Climate change is affecting insect ranges globally due to human movements. In some parts of the US, ants have invaded and consumed wildlife in areas never before exposed to these marauding insects.

Fire

Global warming increases the risk of fires. Recent fires in Australia, Amazonia and California burned over five million hectares of forest wiping out entire species of insects and other wildlife in days.

Storm Intensity

Stronger storms and hurricanes as a result of a warming climate increase the likelihood of lightning fires and flooding.

Droughts

Periods with diminished precipitation are becoming longer, more frequent and warmer with grave consequences for all life.

Nitrification

Fertilisers and products of fossil fuels combustion are nitrifying the planet, challenging ecosystems that have adapted to life in low-nutrient environments. Some fertilisers may also be poisonous to insects and ground-dwelling invertebrates.

Pollution

Chemical, light and sound pollution of water, air and soil are impacting plant, animal and insect life worldwide.

Urbanisation

Our global population of around 7.8 billion people, spread planet-wide, comes at a huge cost to ecosystems and the biodiversity these systems support. The more people there are, the more resources are needed to sustain them.

Introduced Species

Global trade is accelerating the movement of pernicious plants, animals and pathogens to new regions – often with devastating consequences. Invasive species may lead to increased competition for food and shelter, often pushing out native species. Imported animal and plant diseases cause the most damage to life as native species have not been able to evolve a tolerance to these illnesses.

Agricultural Intensification

Industrialised agriculture, with its attendant increases in scale, monoculturalisation, nutrient input and pesticide use is becoming increasingly nature unfriendly.

Insecticides

Modern, industrialised agriculture with its increasing reliance on chemical insecticides, has led to chronic contamination of wildlands and impacts to non-target insects.

Pesticides have a massive impact on insect populations as these usually have a blanket effect, killing all insects present, including those which are beneficial to agriculture.

Deforestation

The tropics lost 11.9 million hectares of forest in 2019, mostly to animal agriculture and palm plantations, decreasing biodiversity to unsustainable levels.

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