On 21 December, immature desert locust swarms from the north first arrived in northeast Kenya where they were seen southwest of Mandera.
In the following days, more swarms arrived along the Dawa River on the Ethiopian border west of Mandera and further south near El Wak and the Somalia border.
“Some of the swarms moved westwards to Wajir and reached eastern Marsabit county on December 27,” a statement from the Food and Agriculture Organization (FAO) reads.
There are also reports of cross-border movements near Moyale with a few of the swarms are maturing.
More swarms are expected from the north that will spread to northern and central counties.
Elsewhere, hopper bands from earlier breeding are present in Marsabit, along the Tana River near Garissa, and on the coast near Lamu.
In Ethiopia, many have fledged and formed immature swarms that are moving south of the Shebelle River towards the south and southwest where they have reached Oromiya (Bale and Borena zones) and SNNP (South Omo zone).
Some hopper bands remain in eastern Somali region. Some of the swarms are maturing and are likely to breed.
In Somalia, hatching and hopper band formation started on the northwest coast and in the northeast between Iskushuban and Bosaso in areas that received heavy rains from cyclone Gati and where swarms laid eggs.
Mature swarms are still present in both areas as well as east of Garowe where more laying and hatching are expected in coastal and plateau areas.
Ground and aerial control operations are in progress. Infestations in central areas appear to have declined; however, there were reports of immature swarms further south to the Juba River.
Elsewhere, breeding is underway along both sides of the Red Sea coast.
In Saudi Arabia, control operations are in progress against hopper groups and bands on the central coast and parts of the north as well as immature adult groups in the centre. More hatching and band formation are expected on the coast between Jizan and Duba.
In Sudan, control continues against prevailing breeding along the Atbara River, near the Egypt border in the northeast, and against laying swarms on the southern coast of the Red Sea.
In Eritrea, breeding is underway on the north coast and a few immature swarms were seen south of Massawa. In Yemen, scattered adults are present on the Red Sea and Gulf of Aden coasts but so far control is not likely to be necessary until the next generation of breeding.
FAO has advised all countries to maintain maximum efforts in conducting the necessary survey and control operations to reduce migration and breeding.