As the Greater Horn of Africa faces its worst desert invasion in over 25 years, the situation remains alarming particularly in Ethiopia, Kenya and Somalia.
Speaking to Africa Science Media Centre (AfriSMC), Mehari Tesfayohannes, Chief information and forecasting officer, Desert Locust Control Organization for Eastern Africa (DLCO-EA) called for the need to control the locust swarms to prevent invasion in other areas.
“The locusts are now restricted in Eritrea, Kenya, Ethiopia, Somalia, Sudan, Yemen and Saudi Arabia. But if they are not controlled well, the invasion will move to other countries,” he cautioned.
The entomologist with over 30 years experience, noted that the insecurity in Yemen and Somalia paved the way for the swarms to move to Eastern Africa as they were not being monitored and controlled.
“Yemen had a very strong plant protection department which was doing regular monitoring and control operations but due to the security situation this was not done. These locusts managed to breed in mass in those areas and they migrated to Somalia,” he explains.
“In Somalia, except in northern parts, they have some activities of monitoring and control but it is not well established to manage any infestation that is coming into the country, so once they entered to northern Somalia they moved to Eastern Ethiopia and Western part of Somalia.”
The reason why countries like Kenya had been spared from an invasion for over 70 years, Tesfayohannes said, was because of the control operations that were ongoing in other countries such as Eritrea, Yemen, Ethiopia, Somalia, Saudi Arabia and Sudan.
However, he adds that because Eastern African countries are not recession grounds, the locusts are likely to migrate out in June.
Recession places are found mainly on the Red sea coastal areas, Northern African countries, the Arabian Peninsula, Saudi Arabia, Yemen, India, and Pakistan, where the locusts will get permissive ecological conditions the whole year round. They live as individuals or scattered until they get favourable ecological conditions for multiplication, Tesfayohannes explained.
The countries in the recession areas do year round monitoring, to check if the number of locusts is increasing or decreasing and to monitor ecological conditions if it is favourable for the locusts or not.
Kenya and other Eastern Africa countries are not recession grounds, he reiterated, so there is no need for them to do year round monitoring and forecasting.
“But they have to monitor the situation around the recession and breeding areas. They have to get the information from those countries on daily, weekly or monthly basis so they prepare themselves ahead if the forecasts say the locusts are moving to Eastern Africa,” Tesfayohannes advised.
The Kenyan situation
“The current infestation in the region is a continuation of infestation which had occurred in 2019,” he said. “ At that time is not only Kenya which was infested by swarms but also Somalia, Sudan, Eritrea, Yemen, Saudi Arabia, Iran, India and Pakistan.”
Tesfayohannes notes that Kenya is witnessing a second year of infestation due to the mass breeding which was going on in Somalia.
“The current swarms came from Somalia and Eastern Ethiopia. We have not seen any migration up to now from the Arabian countries to Eastern Africa,” he said.
The DLCO-EA Chief information and forecasting officer noted that the Kenyan swarms are immature-not ready for breeding. But if they are not controlled, Kenya will experience first generation breeding.
He notes that locust have three breeding seasons, categorized into winter (October to February), spring (March to May) and summer (June to September), where they breed in different locations.
“Kenya is facing the winter breeding season. They came in December now we are in February, they will continue into the spring breeding season. They will continue up to maybe, May or June,” said Tesfayohannes.
“From there, the summer breeding season will come. When the summer breeding season comes to Kenya, they will have to migrate. They have to move out of Kenya and the Eastern Africa region. They will move north to the Arabian countries or to Ethiopia or Somalia.”
He observed that in 2020, the locusts laid eggs in Kenya thrice because the ecological conditions were favourable for breeding throughout the whole year.
“The locusts will continue moving from one country to another if they are not well contained and controlled. Also, if the ecological conditions remains favourable to them,” Tesfayohannes said.
When to control
He advised against spraying the locust swarms if they are in small numbers and the ecological conditions are not favouring them. But if the conditions are favourable, monitoring should be conducted and if the number is increasing, they should be controlled.
“Desert locusts change their colours depending on their biology, pink and yellow in the adult stage. Pink is the one which is destructive- migrating from one location to another in such of food. And once, they start maturing, they change their colour to yellow,” Tesfayohannes explained.
“Once they start ‘yellowing’, we know that their damaging effect is decreasing, they do not feed a lot. They feed a little bit for them to survive and for them to be able to lay eggs. Once they start laying eggs, it is not advisable to spray them.”
He notes that at this stage they will naturally die and advises that the hoppers should hatch before they are controlled.
“An expert must be there to advise which type of locust should be controlled and which type of locust stage should not be controlled. Once they are matured and once they have started scattering, they will die naturally, so there is no need to control them,” he remarked.
By Sharon Atieno