Interview with Alhasanne Adama Diella, hydro-meteorological expert

The swarms of migratory locusts that are invading various African countries were anticipated as far back as last December. How could we have avoided the devastation experienced in northern Africa due to the plague?

We knew that the abundant rain that fell in the Sahel following the last rainy season would generate conditions favourable for locusts to lay their eggs. There was a combination of conditions that together promoted locusts’ rapid reproduction: rain, vegetation and humidity. FAO and other agencies alerted the public last October but their warnings were not heeded. No action was taken to prevent the disaster from occurring. We should have taken the opportunity during the winter that followed the rainy season to increase our efforts in preventing the locusts’ reproduction over the summer in the Sahel. We thus would have avoided the winter-spring reproduction and subsequent invasion in the south of the Maghreb. The responsibility to reduce the impacts of such disasters in this part of the world (Sahel and Maghreb) lies in those neighbouring countries of the Sahara.

The Sahel does not have the sufficient means (equipment and treatment products) nor the finances to avoid such a disaster – much less stop the locust invasion from heading north towards the Maghreb. If we had avoided this migration in the first place, the Maghreb would have been able to prevent the disaster.


The arrival of these insects was forecast by satellite technologies. Are we now able to know when and where exactly they will appear?

The locust invasion is linked to specific conditions such as those I mentioned earlier. Locust reproduction zones in the Sahel and the Maghreb are generally found in less-populated areas, which makes it difficult to consistently monitor their movements as well as trigger early warnings systems. To make up for this, we use satellite technologies. Satellite data allow us to monitor the status of locust reproduction zones as well as prepare us for their consequences.


Why is Africa particularly affected by such hazards today?

There are three main regions of reproduction of locusts in the world: in the west (Sahel and Maghreb); in the central region (around the Red Sea); and the east (along the Indian and Pakistani border).

In this case it is the west that is responsible for the recent plague, as the situation in the other two regions is relatively calm. In the west, the locusts mature within desert and semi-desert zones in the Sahel during the summer. By the end of the winter, the conditions are no longer favourable so they migrate to winter-spring reproduction zones in the Maghreb, seeking better ecological conditions. Locust populations almost always migrate towards the central region at the end of winter. Locust plagues have always threatened Africa and Asia. However, climatic conditions and the effectiveness of those monitoring and prevention programmes in place are what determine their intensity and impact. FAO has established a programme called EMPRES, Emergency Prevention System for Trans boundary Animal and Plant Pests and Diseases that works to prevent such plagues, we should follow this and similar initiatives.


Is this locust attacks considered as a natural disaster ?

Yes, it’s a natural disaster because man has no power over the reproduction patterns of the locusts. He can only destroy the eggs with pesticides after the reproduction has taken place.


Are human activities responsible for the occurrence of locust invasions?

Yes to a certain extent. Human activities have an impact on the climate change, which in turn cause heavy rains that are the ideal conditions for the reproduction of the locusts.


What is the impact of this plague on African economies?

It is difficult to say at this stage, the impact will depend on the importance of agriculture in the country and the time of the year. If the invasion occurs during harvest it will cause a major disaster that will lead to famine. The economic impact can be reduced if the farmers react quickly and save their crops before the invasion but as their power of reaction will be slow the damage will be huge..


What impact does the plague have on agriculture?

Not only does the plague affect crops and plants in general but also has a long-term effect on the environment.


What can the governments do to prevent such a plague?

They can rely on effective means to reduce and monitor the impact of the invasion and stock of pesticides. The key to implementing these strategies is securing financial support. Without money and the support of the International community it will be difficult to address the problem.


Are more locust invasions likely to occur in the near future?

Locust invasions are a recurrent plague in our region. Huge invasions occur in a particular cycle. The heavy rains in the reproduction zones and the failure of the authorities to put in place adequate measures to curb the invasion caused the spread to other countries


Can other continents be affected by the plague?

All the countries belonging to this endemic zone are potentially concerned by the plague. But the locust can also travel from its usual regions to other continents so other countries can be threatened.