Serious Desert Locust situation in the Central and Eastern regions
Although spring breeding has come to an end and despite intensive control operations, several key summer breeding countries face a very serious Desert Locust threat now and in the coming months.
Yemen is the most concerned and at highest risk because of widespread hopper band infestations that will cause swarms to form later this month, which could give rise to another generation of breeding by the end of August if conditions remain favourable. Some ground control operations (500 ha) are underway but their impact against the overall infestations may be limited because not all areas can be accessed and capacities are limited. In addition, groups of adults are present in Wadi Hadhramaut where breeding may occur. In all, there could be a considerable increase in locust populations in Yemen during the summer that would threaten the region.
In the Horn of Africa, mature swarms were seen at several places in northeast Somalia during the past week, and crop damage was reported. Breeding is likely to occur along parts of the northern coast near Bosaso and Berbera that could cause hopper bands to form from late July onwards. Similar breeding is expected to occur in eastern Ethiopia while adult groups may appear in the northern region of Amhara as they move towards the summer breeding areas in western Eritrea and the interior of Sudan.
In Sudan, high numbers of adults are present along parts of the Nile Valley in the north. Scattered adults appeared recently on the Red Sea coast and also in North Kordofan where summer breeding will occur. A few residual swarms from spring breeding areas in Arabia may arrive in these areas by the end of this month and lay eggs.
In India, ground control operations (12 000 ha) are in progress against a number of mature adult groups and swarms that appeared this month in Rajasthan and along the border with Pakistan where they are laying eggs. Similar operations (4 000 ha) are underway against groups of mature adults that are laying in adjacent areas of Tharparkar and Cholistan deserts in Pakistan. Hatching and band formation will occur in both countries during the remainder of July. A second generation of breeding could start as soon as mid-August south of Rohri near the Indus Valley in Pakistan where early breeding occurred in May. The scale and extent of the summer breeding in both countries will depend on this year's monsoon rains, which are so far about two weeks late in arriving to the breeding areas along both sides of the border.
The current Desert Locust situation developed from two cyclones in May and October 2018 that brought unusually heavy rains to a large and remote area in the Empty Quarter of eastern Saudi Arabia that borders Yemen and Oman. Three generations of undetected breeding gave rise to substantial swarms earlier this year that moved to Yemen, Saudi Arabia and Iran. Intensive ground and aerial control operations were mounted in Saudi Arabia (219 000 ha) and Iran (708 000 ha) that undoubtedly reduced locust populations but could not entirely prevent swarms from forming and moving to the summer breeding areas. Residual infestations of adult groups remain in a few places of Iran while a few swarms migrated last month from Yemen to northern Somalia and Ethiopia.