Western appetites for foods like avocados, coffee and citrus fruit are threatening global food security, according to a study that looked at 40 years of data.

Global diversity has declined as monocultures of crops including soybean, canola and palm take up more land than ever.

These crops only provide nutrition for pollinators during a very limited window when they are in bloom. This makes them an unstable source of food for insects, whose global numbers are already rapidly in decline. Heavy use of fertilisers has exacerbated this trend.

“Farmers are growing more crops that require pollination, such as fruits, nuts and oil seeds, because there’s an increasing demand for them and they have a higher market value,” said David Inouye at the University of Maryland and a co-author of the research paper.

“This study points out that these current trends are not great for pollinators, and countries that diversify their agricultural crops are going to benefit more than those that expand with only a limited subset of crops.”

Insects at risk of extinction Show all 12 1 /12 Insects at risk of extinction Insects at risk of extinction Wasps Wasps are of the order Hymenoptera, one of the most at risk Getty Insects at risk of extinction Dragonflies Dragonflies are of the order Odonata, one of the most at risk Getty Insects at risk of extinction Bees Bees are of the order Hymenoptera, one of the most at risk Getty Insects at risk of extinction Butterflies Butterflies are of the order Lepidoptera, one of the most at risk Getty Insects at risk of extinction Ants Ants are of the order Hymenoptera, one of the most at risk Getty Insects at risk of extinction Dung Beetles Two dung beetles making an effort to roll a ball through gravel Getty Insects at risk of extinction Caddisflies Caddisflies make up the order Trichoptera, one of the most at risk Getty Insects at risk of extinction Stoneflies Stoneflies are of the order plecoptera, one of the most at risk Getty Insects at risk of extinction Saw-Flies Saw-Flies are of the order Hymenoptera, one of the most at risk Getty Insects at risk of extinction Moths Moths are of the order Lepidoptera, one of the most at risk Getty Insects at risk of extinction Damselfly Damselflies are of the order Odonata, one of the most at risk Getty Insects at risk of extinction Mayflies Mayflies are of the order Ephemeroptera, one of the most at risk Getty

Researchers analysed data from the United Nations’ Food and Agriculture Organisation (FAO) on the cultivation of field crops between 1961 and 2016. They found that fewer pollinators could mean that yields are much lower or even that harvests fail completely.

Agriculture is most unstable in Brazil, Argentina, Paraguay and Bolivia where expansion of soybean farms has driven deforestation. Soy is often exported to Europe as cattle feed.

“Soy production has risen by around 30 per cent per decade globally,” said Professor Marcelo Aizen of the National Council for Scientific and Technological Research (Conicet) in Argentina, who led the study.

“This is problematic because numerous natural and semi-natural habitats, including tropical and subtropical forests and meadows, have been destroyed for soy fields.”

Palm farming in Malaysia and Indonesia is having the same effect, according to the study published in Global Change Biology.

Although countries replacing forests with monocultures are most vulnerable, other countries are also becoming too dependent on pollinators.

In Europe, for example, farmland is getting smaller as urban development takes the place of agriculture. Pollinator-dependent crops are replacing non-pollinator-dependent crops such as rice and wheat.

This is causing problems in places like the UK, Germany, France, Austria, Denmark and Finland.

Although it is mainly poorer regions that are most at risk the consequences of crop failure would be felt worldwide.

“This work should sound an alarm for policymakers who need to think about how they are going to protect and foster pollinator populations that can support the growing need for the services they provide to crops that require pollination,” said Professor Inouye.

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“The bottom line is that if you’re increasing pollinator crops, you also need to diversify crops and implement pollinator-friendly management.”

Researchers say they hope the research will encourage policymakers to reduce insecticide use, and plant edge rows and flower strips to provide nest sites and food for pollinators.