A ‘devastating’ virus is threatening the world’s chocolate supply

A virus spread by a tiny bug is devastating cacao trees in west Africa – and it could have a major impact on the UK’s favourite sweet treat.

Swollen shoot virus is spread by mealybugs, a fuzzy insect that thrives in hot climates.

The virus – described as one of the most ecologically devastating on Earth – has wiped out 50,000 hectares of cacao farmland in Ghana, which is the world’s second largest chocolate producer.

But scientists at universities in the US and Ghana have found a new way to stop the virus, and hopefully save the world’s chocolate at the same time.

Why is the world’s chocolate under threat?

Around 50% of the world’s chocolate comes from Ivory Coast and Ghana.

However, cacao trees in both countries have been ravaged by swollen shoot virus.

The virus is spread by small insects called mealybugs which eat the leaves, buds and flowers of cacao trees.

Ghana has lost more than 254 million cacao trees in recent years, while around 20% of the cacao crop in Ivory Coast is infected.

Recent heatwaves have made the problem worse, as mealybugs thrive in warmer temperatures.

‘This virus is a real threat to the global supply of chocolate,’ said Benito Chen-Charpentier, professor of mathematics at The University of Texas at Arlington.

What can be done to stop the virus?

Pesticides don’t work against mealybugs, which makes the virus pretty hard to stop.

The cheapest way to prevent the disease is by cutting down infected trees and planting resistant trees.

The farmers can also give trees a vaccine.

However, the vaccine is expensive and has a knock-on effect on the amount of cacao that the tree produces.

Scientists at the University of Kansas, Prairie View A&M, the University of South Florida and the Cocoa Research Institute of Ghana have developed a new strategy for combating the virus.

They hope that by planting trees at a distance from one another, farmers can prevent mealybugs from jumping from one tree to another and spreading the virus.

Researchers used mathematical data to work out the optimal distance to plant trees to minimise the virus spread while still maximising the land.

‘What we needed to do was create a model for cacao growers so they could know how far away they could safely plant vaccinated trees from unvaccinated trees in order to prevent the spread of the virus while keeping costs manageable for these small farmers,’ Chen-Charpentier said.

‘While still experimental, these models are exciting because they would help farmers protect their crops while helping them achieve a better harvest,’ Chen-Charpentier said.

‘This is good for the farmers’ bottom line, as well as our global addiction to chocolate,’ he added.

Is anything else threatening the world’s chocolate supply?

Black pod disease also poses a threat to chocolate production.

The fungal-like disease turns cacao pods black or brown.

Some studies estimate that the disease destroyed up to 30% of the world’s annual cocoa crops in 2022.

Heavy rain last year in cacao-growing regions helped the spread of the disease, as it thrives in moist conditions.

Oliver Shorts, co-owner of chocolate company Seed and Bean, told Metro.co.uk that the farmers they work with have experienced the broader challenges posed by climate change. 

He said it had affected this year’s crops and significantly driven up prices industry-wide.

Kris McGowen from The Raw Chocolate Company said that ‘climate change ‘major global issues’ had been impacting chocolate supply.

‘There are droughts in some places, flooding and too much rain in others,’ he told Metro.co.uk.

‘We have seen cacao prices to us rise to almost four times what they were six months ago, it is very worrying.

‘Coupled with that, African farmers are also protesting, quite rightly, about the poor prices they have been paid in the past, so they are withholding stock which is further putting up the price.’

According to Which?, some Easter eggs and bunnies cost around 50% more this year.