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DESERT LOCUST INVASION

A locust invasion across much of Northern and Western Africa threatened millions of people in more than 10 countries with food insecurity (Figure 1).

Figure 1: The locust invasion in Western and Northern Africa in September and October 2004

More than 10 countries in these African sub-regions were affected by the invasion – the worst since 1986–89.

Source: FAO-Desert locust information service 2004

Desert locusts periodically invade Northern Africa and the Sahel region - the last plague was between 1986-89. In 2004, locusts started invading the Sahel region from the end of June, with Mauritania, Mali, Senegal and Niger the worst affected. More than 2.5 million rural households were at risk of food shortages as over four million ha of crops and farmland were devastated by the swarms. In Mauritania about 1.6 million ha were invaded and an estimated 80 per cent of crops were destroyed (FAO 2004a). The invasion also affected national economies. For example, Morocco spent about US$30 million in defence of an agricultural sector worth US$7 billion in 2002, US$1 billion of which are export earnings (FAO 2004b).

A goat herd runs away from a swarm of desert locust near Kaedi, Mauritania. Livestock are in competition with the insects for available grazing land.
Source: FAO Photo Gallery

Ironically, good rains, which would normally boost agricultural production, also provided ideal weather conditions for the locusts to multiply. The desert locust has been described as a pest of unusually destructive powers (FAO 2004b). A tonne of locusts - just a small part of an average swarm - eats the same amount of food in a day as 2 500 people. Each swarm is composed of millions of insects, sometimes covering several square kilometres. One swarm spotted in northern Mauritania during the invasion was 70 km long. Adult locusts can fly over 200 km per day (FAO 2004a).

The Food and Agriculture Organization of the United Nations (FAO) appealed to the international community for US$100 million to help contain the locusts (FAO 2004a). Control involves spraying, and to reduce risks to human health and the environment FAO has promoted the use of pesticides that usually degrade in a week. FAO and governments in the region are seeking even safer replacements, testing a fungus that attacks locusts in the field, and a natural hormone that disrupts the insects' normal behaviour (FAO 2004a).

The Centre for Ecotoxicological Research in the Sahel, established in Senegal in 1991 with FAO assistance, helps governments to monitor the risks to environmental and human health from pesticides. It also helps governments to establish safety measures, to check people's health, and to ensure the safe handling of pesticide residues. The centre also trains national environmental monitoring teams and collaborates with national chemical laboratories and other institutions such as universities (FAO 2004c).


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