The Two Drivers of Massive Insect Population Die-Off Have Finally Been Identified

They help us put food on the table. They are food for many animals.

As renowned ecologist E.O. Wilson said, "insects are the little things that run the world." At least 87 of humanity's major crops depend on them, but it's getting harder for insects to survive on our planet.

The clearing of massive swaths of their natural habitat, introduction of toxic chemicals into their environments, and rising temperatures are some of the problems we have caused.

Using data on insect abundance and biodiversity for more than 6,000 different locations worldwide, University College London ecologist Charlie Outhwaite and colleagues looked at how changes in insect abundance and biodiversity trended across 20 years with two factors: agricultural intensity and climate warming.

In this study, we use the PREDICTS database to assess the impact of the interaction between land use and climate change on global insect biodiversity. More than 6,000 sites including almost 20,000 insect species were available. pic.twitter.com/vYQPAjbsix

— Charlie Outhwaite (@CharlieLouO) April 20, 2022

Areas of intensive agricultural use have experienced large increases in warming over the last 20 years.

We found that in high intensity agriculture that has also seen substantial warming, abundance and richness are reduced by 49% and 27% relative to primary vegetation where there has been little warming. pic.twitter.com/yusvGpdtdf

— Charlie Outhwaite (@CharlieLouO) April 20, 2022

When there was a lot of natural habitat, insect declines were reduced. In areas with three-quarters of natural habitat still intact, the amount of insects dropped only 7 percent on average and the number of different species only by 5 percent, compared to areas with less than a quarter of remaining natural habitat.

Preserving natural habitats near farmland may help to ensure that vital insects can still thrive, according to Tim Newbold, also from the University College London.

Changing the types of crops grown in one area and using fewer pesticides andfertilizers is part of lowering farming intensity. These actions give insects with more safe areas to retreat to during hot weather as well as ensure there is enough food and other resources for them, so they can continue doing the work that we all rely on.

Growing a diverse range of native plants wherever we can is something the rest of us can help with.

The tropics and the Mediterranean were found to be the hardest impacted places due to habitat change and increased temperatures. Brazil has seen a decline in orchids by around 50 percent.

Other studies have shown a worldwide increase in freshwater insects, but not all species are doing worse.

Many of these positive trends have been reported in non-tropical regions such as the UK and Europe, where a lot has been done to improve the water quality of rivers.

Half of all known living things are insects. This is a huge chunk of all the existing life we know of in the Universe, and we don't yet fully understand how we messed it up.

The findings show the importance of actions to preserve natural habitats, slow the expansion of high-intensity agriculture, and cut emissions to mitigate climate change.

The health, wellbeing and livelihoods of many people in the tropics and beyond are hanging in the balance because of the effects of climate change and biodiversity loss.

Nature published their research.