Guinea-Bissau's government has warned that new swarms of locusts are threatening its vital cashew nut crop.
A single locust can eat its own weight each day
Government spokesman Filomeno Lobo de Pina told Portugal's Lusa news agency the country did not have the resources to combat the crop-devouring insects.
The cashew trees were now flowering and the swarms could imperil the 90,000 ton export crop, he said.
Locust infestations have hit crops across West Africa over the past year.
"This could seriously affect our trade balance," Mr Lobo de Pina said.
One of the poorest countries in the world, Guinea-Bissau relies on its cashew nut exports for crucial foreign currency earning.
The Food and Agriculture Organisation (FA0) has said it is sending assistance to Guinea-Bissau, following the government's appeal last week for international aid.
Despite extensive spraying - some 12m hectares since October 2003 - the locust situation remains serious, the FAO has warned.
An international scientific conference on locusts to review the current situation in the region is due to take place in Senegal this month, the organisation said.
Countries have been urged to prepare themselves for another upsurge in locust numbers this year after the winter breeding season.
"Countries in west and north-west Africa have made great efforts in controlling the swarms coming out from the Sahel," the FAO said in a statement last week.
"But only in March - April 2005 will it be possible to have clear indications on what scale breeding will occur and on what scale the Sahel will be reinvaded in summer."
Mauritania has been the worst-affected country, with up to half of all cereal crops consumed by the insects.