Why 500 million bees have died in Brazil in three months

More than 500 million bees have died in Brazil in the last three months.

In the state of Rio Grande do Sul, 400 million dead bees were found - with beekeepers in four states reporting the mass deaths.

Researchers have blamed the use of pesticides - chemical substances which are used to kill pests.

Bees have a really important role in the food chain - with around one-third of the food we eat relying on pollination mainly by bees.

These include fruits and vegetables such as avocados, broccoli and cherries.

The main cause of death for these bees has been the use of pesticides containing products that are banned in Europe, such as neonicotinoids and fipronil.

The EU imposed an almost total ban on neonicotinoids last April because of the serious harm it could cause to bees.

But in the same year Brazil lifted restrictions on pesticides - despite opposition from environmentalists who called it the "poison package".

The use of pesticides in Brazil has increased, according to Greenpeace, with 193 products containing chemicals banned in the EU being registered in Brazil in the last three years.

The country uses pesticides because its economy is so reliant on agriculture.