Madagascar is at risk of being overrun by a locust plague likely to ravage at least two-thirds of the country and spark a serious food crisis, the UN's food agency said on Wednesday.
"If we don't act now, the plague could last years and cost hundreds of millions of dollars," the agency's director general Jose Graziano da Silva said in the report.
"This could very well be a last window of opportunity to avert an extended crisis," he said.
In an emergency fund-raising appeal, the Rome-based Food and Agricultural Organisation (FAO) said it needed about $22 million (16.8 million euros) to get a control campaign in place by the start of the next crop planting season in September.
"Some 13 million people's food security and livelihoods are at stake, or nearly 60 percent of the island's total population. Nine million of those people are directly dependent on agriculture for food and income," the FAO appeal said.
By September, Madagascar's worst locust plague in 60 years will have infested two-thirds of the Indian Ocean island's crops, FAO experts said.
The agency said over $41.5 million was needed to complete the necessary three-year programme to reverse the plague, and warned that not contributing now would have severe financial consequences.
"Preventive control measures normally cost $3.3 million per year for the 10 affected Sahelian countries. So intervening only when the situation reaches a crisis point cost roughly the same as 170 years of prevention," it said.
According to experts, there are currently one hundred locust swarms across Madagascar, made up of about 500 billion ravenous locusts which get through around 100,000 tonnes of vegetation every single day.