Desert Locust Bulletin 452 (May 2016) [EN/AR]

General Situation during May 2016
Forecast until mid-July 2016

The Desert Locust situation in Yemen continues to deteriorate as more hopper groups and bands formed in the interior as well as on the Aden coast during May. Insecurity and remoteness are hampering current survey and control efforts. Consequently, swarms will start to form in the coming days. If vegetation remains green, the swarms are expected to remain in the interior between Marib and Thamud where they will mature with the possibility of another generation of egg-laying by mid-July. On the other hand, if vegetation dries out, then the swarms are likely to move south to the Gulf of Aden where strong south-westerly monsoon winds would carry them through coastal areas of Oman and across the Arabian Sea to the Indo-Pakistan summer breeding area. Their arrival would nearly coincide with that of the monsoon rains in Rajasthan and adjacent areas of Pakistan. Swarm movement from the Yemen interior to Saudi Arabia is not very likely. All efforts are required to increase survey and control operations in Yemen wherever possible and to remain vigilant in other countries. FAO will continue to monitor the developing situation closely and provide timely early warning. Elsewhere, the Desert Locust situation is generally calm. Control operations continue against adult groups in the southern part of the Western Sahara in southern Morocco and adjacent areas of northern Mauritania. A limited number of groups are likely to reach the summer breeding areas in southern Mauritania and lay eggs with the onset of the seasonal rains. Control operations were carried out during May against locally-bred adult groups in central Algeria.

Western Region. Ground control operations declined during May in the southern portion of the Western Sahara in Morocco and in northern Mauritania, treating 218 ha and 762 ha respectively of adult groups as well as hopper groups in Mauritania. As vegetation dried out further, adults rapidly increased in density and several groups moved south within this area to oases in western Mauritania. This movement is expected to continue during the forecast period when adult groups are likely to reach the summer breeding areas in southern Mauritania and lay eggs with the onset of the rains. Hatching could commence by the end of the forecast period if early rains and egg-laying occur. In the central Sahara of Algeria, ground teams treated 651 ha of adult groups that formed from local breeding. Scattered adults were reported in southwest Libya, southern Algeria, northern Mali and in the Air Mountains of northern Niger.

Central Region. The situation deteriorated further in the interior of Yemen where more hopper groups and bands formed from local breeding throughout May. Although the full extent of infestations is not well known due to insecurity, it appears that breeding has occurred within a large portion of the interior from Marib to Thamud as well as on the Aden coastal plains. Only limited control operations could be carried out, some by burning hopper bands. Consequently, swarms will almost certainly form from early June onwards. If vegetation remains green, the swarms are expected to remain in the interior and mature with the possibility of another generation of egg-laying by mid-July. On the other hand, if vegetation dries out, then the swarms are likely to move to the southern coast and be carried by strong south-westerly monsoon winds through coastal areas of Oman to the Indo-Pakistan summer breeding area. Elsewhere, the situation remained calm. Small-scale breeding continued in northeast Oman and occurred near crops in southern Egypt. Good rains fell on the plateau in northern Somalia and eastern Ethiopia.

Eastern Region. No locusts were reported and the situation remained calm in the region during May. There is a low to moderate risk that a few small swarms could arrive along the Indo-Pakistan border if vegetation dries out in the interior of Yemen.