Thursday, June 10, 2004

North Africa: more on locusts

New Scientist article gives more info on the locusts that threaten crops in northern Africa.
[...] experts have told New Scientist that fears that the swarms may hit Europe may be unfounded as this would require "unusual winds". Furthermore, locusts have never been known to thrive in Europe.

[...] A much greater worry is that the insects could breed to plague proportions and ruin the livelihoods of poor African farmers and affect food security. The last African locust plague lasted from 1986 to 1989 and struck 40 countries.

In 2003, exceptionally wet rainy seasons in the Sahel and northern Africa meant that the desert locust species (Schistocerca gregaria (Forskal)) was able to breed more generations of offspring than usual, leading to a population boom.

"It's important to control in terms of protecting crops in the Sahel and trying to prevent it from getting any bigger," Elliott told New Scientist. "Possibly this summer is the last chance to do so. Once it really gets going it's extremely difficult to deal with as the population gets larger and larger."

Previous plagues of the 1940s and 1950s lasted 10 or 15 years, and hit as many as 65 countries, says Elliott. "It would be fairly horrendous if we moved into that scale," he warns.

The north African countries currently suffering swarms - Morocco, Algeria, Tunisia and Libya - are making "tremendous efforts" to control the insatiable pests, he says. But because the locusts cover such a huge area, Elliott predicts that substantial numbers of swarms will escape and move back into the Sahel later in 2004.
Whether the locusts have another successful breeding round will depend on the summer rains in the Sahel, he says. But reports suggest the rains may have already started. "Then we would expect that by the end of 2004 that a full blown plague will have developed."

A plague of locusts is defined as a large, gregarious population present in at least two major regions. Locusts are normally lone creatures, but when times are good and their numbers boom, they modify their behaviour and group together gregariously. Elliott predicts that the locusts could spread to West Africa and eastwards to Sudan and even the Red Sea region. (full-text)