Fresh appeals are being made for urgently needed international aid as swarms of locusts continue to spread across West Africa.
Requests have been made for planes as well as pesticides
The leaders of 12 nations have agreed a plan to fight the locusts.
But a United Nations agency warns that it needs tens of millions of dollars in extra funding to stop a plague.
The Food and Agriculture Organization says locusts have caused significant crop damage in several countries and the situation could worsen.
It is warning that without urgent action this month the locusts could wreak havoc across west Africa.
The locusts are multiplying at an alarming rate and many crops are coming close to harvest.
In the past couple of months, huge swarms of locusts have moved from northern Africa to western African countries, in what is the worst such crisis to hit the region in 15 years.
Food shortages feared
By responding quickly with pesticides, Arab countries managed to contain the damage.
But in western Africa, where governments do not have the same resources to prevent the locusts from breeding, the situation is getting worse day by day.
Many people in west Africa are small farmers and, if no way is found to stop the insects from breeding and spreading, there could be serious food shortages.
West African leaders have pledged to co-operate with each other to combat the pests.
They have appealed to international donors to help them by giving them pesticide and planes as soon as possible.
The president of Mali and his cabinet said this week that they would forego a month's salary, so the money could be used to help fight the locusts.
But the FAO says only substantial and immediate international help can avert a crisis.
It says of the $100m it has repeatedly appealed for, it has only received or been pledged one-third of that amount.