West Africa is facing a worsening locust crisis as more swarms arrive in Mauritania, Mali and Niger, according to the latest update issued by the UN Food and Agriculture Organization (FAO).

With the threat of serious damage hanging over several Sahelian countries, the Chairperson of the African Union Commission, the former President of Mali, Alpha Oumar Konare, and FAO Director-General Jacques Diouf are visiting Mauritania for a first-hand look at the locust swarms and the damage they cause.

First adult locusts could appear by end of the month

In Mauritania, swarms of locusts moving from the north towards the south were reported in Tiris Zemmour, Adrar, Inchiri and the capital Nouakchott. According to FAO, the first adult locusts of the summer generation could start to appear by the end of August.

Locust control operations treated 6,029 hectares in Mauritania during the first 10 days of August.

In Senegal, FAO reports that swarms and hopper bands, newly hatched wingless locusts, were present along the Senegal River Valley and were also in the Ferlo Valley at Linguere. More than 16,000 hectares of infestations have been treated by Senegal from 8 July up to 13 August.

Good rains create excellent conditions for locusts to breed

According to FAO, the main reason for the enormous numbers of locusts is that a series of good rains have fallen, first in the Sahel during the summer of 2003, and then in Northwest Africa during winter/spring. This created favourable ecological conditions for locust development in the region and allowed at least four generations of locusts to breed one after the other.

Locusts are also reaching unusual places. On 5 August a few swarms reached, for the second time, the Cape Verde Islands of Boa Vista, Santiago, Fogo and Maio during another brief period of northeasterly winds. The swarms contained up to 50 adult locusts per square meter. Numerous dead locusts were sighted on the beaches.

Locust situation improves in Algeria and Morocco

The situation in the first 10 days of August was becoming calm in Morocco and Algeria, where immature adult groups were only reported from a few locations. Less that 7,000 hectares were treated in each country. As the vegetation is drying out, no further development is expected in the coming weeks.