A United Nations report found that the devastation caused by the swarms have left millions of citizens in need of emergency food aid.    

The findings from the UN Food and Agriculture Organisation, which recently concluded a joint assessment with the Ethiopian government, come as the region is bracing for new swarms that could be even more destructive.

This second wave of pests to spawn in Africa could to be 20 times larger than the first - which was already the worst in 70 years in some nations.

The desert locusts, some in swarms the size of Moscow, have already chomped their way through much of East Africa, including Ethiopia, Somalia, Kenya, Djibouti, Eritrea, Tanzania, Sudan, South Sudan and Uganda.

Their breeding has been spurred by one of the wettest rainy seasons in the region in four decades.

In Ethiopia, the locusts have caused widespread losses of sorghum, wheat and maize, also known as corn, and vastly reduced the amount of available land for cattle grazing, FAO said.