Desert Locust Bulletin 391 (April 2011) [EN/AR]

Situation Report
Originally published


General Situation during April 2011
Forecast until mid-June 2011

Desert Locust infestations persisted during April in northwest Mauritania and on the Red Sea coast in Saudi Arabia but declined in Egypt and Sudan. Ground and aerial control operations were undertaken in Saudi Arabia against another generation of breeding while smaller ground operations were conducted in Mauritania, Egypt, southern Morocco and Algeria. Small-scale breeding occurred in western Pakistan and southeast Iran. During the forecast period, if the remaining infestations in Saudi Arabia are not controlled, new adult groups and small swarms could form on the coast and move into the interior during May and perhaps across the Red Sea to Sudan in June. Any adults remaining in northwest Mauritania will move to the summer breeding areas in the south of the country in June. Therefore, all efforts should be made to control current infestations in order to reduce migration to the spring and summer breeding areas.

Western Region. Groups of hoppers and adults formed in northwest Mauritania and adjacent areas of southern Western Sahara in Morocco during April. Ground teams treated more than 8,000 ha in Mauritania and 300 ha in Morocco. Low numbers of adults persisted along the southern side of the Atlas Mountains in Morocco. In Algeria, hatching near irrigated crops in the central Sahara caused locusts to increase and form small groups of hoppers and adults that were treated (440 ha). No locusts were reported in the northern Sahel of West Africa where dry conditions prevailed. During the forecast period, adult numbers will increase in northwest Mauritania in May but decline during June as adults move towards the summer breeding areas in the south of the country. This year, somewhat higher than normal numbers are expected to appear prior to the onset of the summer rains.

Central Region. Another generation of hatching occurred on the central Red Sea coastal plains in Saudi Arabia, causing locust numbers to increase during April. Aerial and ground control operations treated more than 13,000 ha of hopper bands and groups of hoppers and adults. Locust infestations continued to decline on the Red Sea coast in Sudan and Egypt. Ground teams treated 2,150 ha in Egypt. No locusts were reported elsewhere in the Region. During the forecast period, more hopper bands and adult groups will form on the Red Sea coast in Saudi Arabia. As vegetation dries out, adult groups and perhaps a few small swarms are likely to move into the spring breeding areas of the central interior in May while in June they are more likely to cross the Red Sea to northeast Africa. If adults arrive in the interior of Saudi Arabia, small-scale breeding will occur in areas of recent rainfall.

Eastern Region. Small-scale breeding occurred in the spring breeding areas of Baluchistan in Pakistan and, to a lesser extent, in Iran during April. Locust numbers will increase slightly in May but then decline during June as low numbers of adults move towards the summer breeding areas along the Indo-Pakistan border.