A plague of locusts has hit the Algarve region on Portugal’s southern coast, a top European tourist spot. The clouds of hungry insects have already devastated millions of acres of crops in north and west Africa and are now rapidly invading Europe. The UN Food and Agriculture Organization (FAO) is predicting that this could be the worst locust swarm in 15 years.

Early warnings of the plague came as early as June this year when swarms of locusts were reported in Morocco, Algeria, Tunisia and Libya. In October, UNFAO expert Clive Elliot said that if summer rains arrive in the breeding grounds, “By the end of 2004 [we would expect] that a full-blown plague will have developed.”

It has already happened. Only last week Spain’s Canary Islands were swarming with over 100 million locusts, just weeks before, they ruined more than 2.5 million acres of crops on Africa’s North coast in Mauritania.

This crop devastation could potentially cause widespread famine in affected countries like Mauritania where 80 percent of the people depend on the land to make a living. In the south of the country entire harvests have already been wiped out by the locusts.

Luckily, the locust plague may not cause severe damage to Portugal due to favorable weather conditions—bad weather. Experts say most of the locusts will not survive the recent cold temperatures and heavy rain that have hit the region, although some may hibernate and return in the spring.

According to the BBC, the Spanish government is not overly concerned with possible threats. Antonio Ortega, director general of the regional agriculture department, said the flying pests that are carried north by wind and rain are dying off. “They are having problems feeding, they’re tired from traveling, and many have lost legs and wings and are dying,” he said.

The last locust plagues were in the 1940s and 1950s and lasted 10 years or more and affected 65 countries. The last African locust plague, affecting 40 countries, lasted from 1986 to 1989.

Locusts, which are simply aggressive grasshoppers, begin to multiply rapidly when food becomes abundant. A heavier than usual rainy season in 2003 in the Sahel (an area ranging from the Atlantic Ocean to the horn of Africa) and northern Africa led to a population boom of the locusts.

In a single day, an average swarm can eat the same quantity of food as 2,500 people, easily destroying vegetation and crops.

Little is known about what causes groups of grasshoppers to become ravaging swarms of flying insects, but it seems that “tickling” the insects’ legs may set off an army of crop-hungry beasts. New research at Oxford University suggests that the sensitive hairs on the insects’ legs could activate swarming. Stephen Simpson, head of Oxford’s research team on the issue, says that the nervous system sends a message to the insects’ brain, which in turn triggers a chemical reaction that results in swarming.

The FAO, based in Rome, put out requests for donations to fight the locust swarms, but by mid September they only received USD $4 million. The tally of aid is now up to $15 million with pledges of a further $40 million. The FAO estimates it will need $100 million to tackle the locust plague.