Several East African countries including Kenya, Ethiopia and Somalia are fending off looming locust swarms up to 37 miles long and 25 miles wide that descend and devour crops.
The scale of infestation has not been seen in more than a half century.
Swarms travel up to 100 miles per day with a tailwind, and consume nearly all green vegetation in their path, with clouds of 40 million critters gobbling up an equivalent amount that 35,000 humans would eat.
The United Nations says $76 million is needed immediately to boost spraying of insecticides.
War in Yemen and Somalia have created havens for locusts to breed as countries mired in conflict can do little to curb their numbers.
An El Nino-like event in the Indian Ocean caused a shift in the rainfall calendar this year, which initially helped crops grow and alleviated a long drought.
However, the same conditions spurred an explosive breeding season for locusts.
The Indian Ocean warm spell usually happens about once a decade, but climate scientists have shown they are becoming more frequent and more intense as global temperatures rise.
Duel cyclones in May and October 2018 spurred more off-season vegetation for the locusts to feed on in the Arabian peninsula and southern Iran, India and Pakistan.
Those swarms moved to Ethiopia and Somalia in October last year.
Rainy conditions are expected to continue through June. Some analysts predict swarms will get worse in the coming months, reaching up to 400 times their current size.
In Somalia, the UN Food and Agriculture Organization is helping to deploy biopesticides.
Instead of chemical pesticides, they spray spores of a fungus, Metarhizium acridum, which makes a toxin that kills only locusts and related grasshoppers.
Researchers have been developing the alternative since the last massive locust outbreak in Africa in 2003 through 2005.
The alternative is now cheaper, more effective, lasts longer in the desert heat, and is easier to store than it was last time around.
Analysts say the infestation will spark a humanitarian crisis in the coming months, with severe food shortages and food insecurity as new waves of locusts pester planting season in March and harvests over the summer.
The UN Ambassador for Kenya, Lazarus O. Amayo, said in a statement that the crisis could also spur communal conflicts as livestock herders will be forced to move animals into new territories for grazing.
Hundreds of Billions of Locusts – Fueled By Conflict and Climate Change – Are Swarming East Africa (Washington Post)
Locust Swarms As Big As Cities Are Causing A Crisis In Africa As Experts Warn They Could Get 400 Times Bigger (Newsweek)