General Situation during November 2004
Forecast until mid-January 2005
The Desert Locust situation remained serious during November. A substantial number of immature swarms from the Sahel continued to arrive in Northwest Africa where intensive aerial and ground control operations were already in progress. A few swarms reached the Canary Islands and southern Portugal. Several swarms moved west in the Sahel and reinvaded northern Burkina Faso, Mali, Mauritania and northeastern Senegal. Some of these swarms were associated with the Southern Circuit migration and could eventually reach southeastern Senegal and Guinea. Other swarms moved east across northern Egypt and reached Israel, Jordan and Saudi Arabia while some adults were seen in Lebanon and Syria. Conditions improved in northwest Mauritania where breeding could occur during the forecast period.
Western Region.
Although the situation improved in the Sahel as numerous swarms continued to move north and arrive in Morocco, Algeria, Tunisia, and Libya, immature swarms persisted in southwest Mauritania. At mid-month, swarms from late summer breeding in the Sahel reinvaded northern Burkina Faso and moved into southwest Mali, a relatively rare Southern Circuit migration. Other swarms reinvaded western Mali, southern Mauritania and northeastern Senegal, and there was an uncon.rmed reporte from Gambia. These infestations were probably a mixture of early second-generation swarms and late developing swarms from summer breeding in the Sahel. Unusually strong and warm winds at the end of November allowed a few swarms to reach the Canary Islands and southern Portugal where they subsequently dispersed and were blown back to sea. Smaller infestations were present and are likely to persist in northern Mali and Niger and in Cape Verde. Egg laying, hatching and band formation are expected to occur during the forecast period in northwest Mauritania where habitats have now become favourable. Aerial and control operations treated 2.2 million ha in the region during November.
Central Region.
Some immature swarms that arrived on the northwest coast in Egypt at the end of October moved east during November along the Mediterranean coast while others appeared in the Western Desert along the Libyan border. Those in the north eventually reached the Nile Delta and Cairo before dispersing over a large area of the Sinai Peninsula, the eastern Mediterranean and the northern Red Sea. Several groups and swarms invaded southern Israel, Palestine, western Jordan, Cyprus, and the northern Red Sea coast in Saudi Arabia. Smaller infestations appeared on the coast in Lebanon and Syria and on the Red Sea coast in Egypt. Control operations were conducted in most of the affected countries. There is a risk that infestations will appear in traditional winter breeding areas along the Red Sea coast where, given suf.cient rainfall, breeding could occur and hopper bands could form in January.
Eastern Region.
No locusts were reported during November in the Region, and no signi.cant developments are likely.
Weather & Ecological Conditions in November 2004
Good rains fell in northwest Mauritania during November, causing habitats to become favourable for breeding. Good rains also fell along the Atlas Mountains in Northwest Africa but decreasing temperatures will limit locust maturation and breeding. Rain fell in the winter breeding areas along both sides of the Red Sea. Vegetation continued to dry out in the Sahel.
In the Western Region, the Inter-Tropical Convergence Zone (ITCZ) continued to retreat south of 15N during November. From mid-month onwards, it was well south of the locust breeding areas in the Sahel in West Africa. Good rains fell on 7-10 November in Cape Verde and extended to northwest Mauritania (Inchiri and southwest Adrar) and southern and central areas of Western Sahara on the 8-9th. The rains were suf.cient in Mauritania and Western Sahara to allow habitats to become favourable for breeding in the second half of the month. Although no rainfall occurred in the Sahel and vegetation is nearly dry or rapidly drying out in all areas, good conditions persisted in the wadis of the Adrar des Iforas in northern Mali and in the eastern part of the Air Mountains in Niger. In Northwest Africa, dry conditions persisted in the Sahara south of the Atlas Mountains. Light to moderate rains fell along the southern foothills of the Atlas Mountains and in the valleys of the Middle and High Atlas in Morocco and Algeria, including the Souss Valley, where conditions were better. Libya was dry, except in the centre where good rains fell, making habitats favourable for local breeding. Throughout the month, numerous depressions formed over the eastern Atlantic and moved east through the Mediterranean. Strong, warm southerly winds occurred for a day or two with each depression that allowed locusts to move further north and east in Northwest Africa as well as off shore to the Canary Islands and southwest Europe.
In the Central Region, light rain fell in a few places on the Red Sea coast in Sudan south of Port Sudan, in Saudi Arabia near Mecca and Jizan, and in Yemen. In the latter area, conditions continued to be favourable for breeding. In northern Somalia, moderate to heavy rains fell in the interior between Erigavo and Las Anod, moderate rains fell on the northwest coast, and isolated showers fell near Hargeisa. Warm southerly winds associated with depressions over the eastern Mediterranean and lasting a day or two occurred several times during the month. These allowed locusts to move in a northeasterly direction from northern Egypt. During the remainder of the month, prevailing winds over the northern part of the Central Region were generally cold and from the north except in the Red Sea Trench where they were warmer. As a result, adults could move south along the shores of the Red Sea.
In the Eastern Region, no significant rainfall occurred and dry conditions prevailed during November.
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