As human activities rapidly transform the planet, the global insect population is declining at an unprecedented rate of up to 2% per year. Amid deforestation, pesticide use, artificial light pollution, and climate change, these critters are struggling, along with the crops, flowers, and other animals that depend on them for survival.
The world has lost 5% to 10% of all insect species in the last 150 years, or between 250,000 and 500,000 species, according to a February 2020 study in the journal Biological Conservation. Those losses continue, though estimates vary due to spotty data, as well as uncertainty about how many insects are out there.
The disappearance of the insects cannot be attributed to a single cause. Populations face simultaneous threats, from habitat loss and industrial agriculture to climate change. Nitrogen overload from sewage and fertilizers has turned wetlands into dead zones; artificial light floods the night skies, and the growth of urban areas has led to the expansion of concrete.
Insects are the largest group of animals on the planet. There are an estimated 5.5 million species, 80% of which remain to be discovered. However, insects are experiencing steep and widespread declines around the world a “ Death by a thousand cuts ” due to human activity.
Insects perform nearly every conceivable role in an ecosystem, including pollinating crops, controlling pests, and serving as food for other animals. The potential consequences of its decline are so dire that it has been dubbed the “bug apocalypse.”
Following the wave of attention generated by this impending environmental catastrophe, a complex picture has emerged, with a gap in our understanding clearly clear. Despite the fact that tropical and subtropical regions are home to an estimated 85% of Earth’s insects, what is happening in those regions is very little studied.
Climatic stress half number of insect
- Insects pollinate more than 75% of global crops, a service valued at up to $577 billion per year, says the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
- In the United States, insects perform services valued in 2006 at an estimated $57 billion per year, according to a study published in the journal BioScience.
- Dung beetles alone are worth about $380 million a year to the US livestock industry for their work breaking down manure and churning up pasture soil, the study found.
- Several recent studies warn of the vertiginous global disappearance of insects that are taking place in the 21st century, especially in the less studied tropical zones.
- A study published in Nature warns that croplands subjected to climatic stress have half the number of insect specimens and 25% fewer species than natural habitat areas.
- The number of flying insects in Britain has fallen by almost 60% since 2004, according to a report that tallied splashes on car number plates.
What to do to stop the collapse?
In the most intensive agricultural areas, where the forest and native vegetation have completely disappeared, the reduction of insects averages 63%. However, in the less intensive ones, where agricultural farms are combined with patches of wild species, the reduction remains at 7%.
According to the study, maintaining natural habitats, however small and fragmented, can mitigate insect collapse. In addition, these actions are especially effective if they are combined with agricultural techniques that are not very intensive in the use of fertilizers and pesticides.
“For agriculture, insects are essential. They provide very important ecosystem services, beyond pollination, such as pest control or increasing crop resistance”, explains Charlie Outhwaite, Research Associate at University College London. “Building a food system that is safe for insects means reducing the intensity of agricultural methods in some areas and providing additional resources for insects. This in turn is a challenge if we think we need to provide more food for a growing human population.”