The Yemeni government is concerned that new swarms of locusts in the south of the country, and the billions of offspring they are likely to have, will have a devastating effect on crop harvests.

According to the Desert Locusts Control Centre (DLCC) at the Ministry of Agriculture, over the past few days mature desert locusts have descended over 30 sq km in Thamoud, a desert area in the southern province of Hadhramout.

With a density of 30 locusts per square metre, there would be about 900 million locusts in these swarms. However, specialists say they pose no immediate threat to the area, but that, with each locust carrying between 300 and 500 eggs, the danger lies in the next generation.

“We have entered into a critical stage, and the situation seems dangerous as the new locusts are now laying eggs that will hatch in three weeks,” Abdu Farei al-Rumeih, General Director of the DLCC, told IRIN on Wednesday.

“The new generation will destroy grazing fields and deprive beekeepers and herdsmen from what seems a good harvest,” he added.

Al-Rumaih said nine teams consisting of 27 experts are monitoring the new swarms. The teams have yet to identify the direction from which the new swarms came. But he is concerned about other swarms that have not been discovered.

“In the surrounding areas, there are locusts but with a lower density of five to seven locusts in each square metre. But what is worrying is the swarms that have not been discovered,” he said, adding the field teams were asking citizens to report any locusts they find.

Last month, migratory locusts descended upon 27 sq km of farmland in the western province of al-Hudaidah, but field teams managed to control the situation.

Specialists say a small swarm of locusts can eat as much food in a day as 2,500 people. A swarm can have up to 80 million adult locusts in each square kilometre, and is capable of destroying a crop field in seconds. Nearly all crops, and non-crop plants, are at risk.

Following warnings by the United Nations Food and Agriculture Organization (FAO) of locust swarms coming from Eritrea, Yemen’s Ministry of Agriculture has already set up an emergency plan to control them on their arrival. This includes sending teams to fumigate affected areas.

Yemen is at the crossroads of swarm migrations originating from eastern countries - such as India, Pakistan, Afghanistan, Iran and Oman - and central areas – such as the rest of the Arabian Gulf, Sudan and the Horn of Africa.

Swarms from any of these places could reach Yemen, depending on the level of locust breeding, and prevailing winds and rains, specialists say. The country witnessed damaging locust invasions in 1986, 1987, 1993 and 1998, with 1993 having a particularly serious outbreak. Additional outbreaks in 2002 and 2004 were successfully controlled.