【单选题】

The government-run command post in Tunis is staffed around the clock by military personnel, meteorologists and civilians. On the wall are maps, crisscrossed with brightly colors arrows that painstakingly track the fearsome path of the enemy.

What kind of invader gives rise to such high-level monitoring Not man, not beast, but the lowly desert locust. (蝗虫)In recent months, billions of the 3-inch-long winged warriors have descended onAlgeria, Libya, Morocco and Tunisia, blackening the sky and eating up crops and vegetation. The insect invasion, the worst in 30 years, is already creating great destruction in the MiddleEast and is now treating southernEurope. The current crisis began in late 1985 near the Red SeA、Unusually rainy weather moistened the sands of the Sudan, making them ideal breeding grounds for the locust, which lays its eggs in the earth. The insect onslaught threatens to create yet anotherAfrican famine.Each locust can eat its weight (not quite a tenth of an ounce) in vegetation every 24 hours.A、good-size swarm of 50 billion insects eats up 100,000 tons of grass, trees and crops in a single night.
All $150 million may be needed this year. The U. S. has provided two spraying planes and about 50,000 gal. of pesticide. TheEuropeanCommunity has donated $3.8 million in aid and the Soviet Union,Canada, Japan andChina have provided chemical- spraying aircraft to help wipe out the pests.But relief efforts are hampered by the relative mildness of approved pesticides, which quickly lose their deadly punch and require frequent replications. The most effective locust killer dieldrin has been linked to cancer and is banned by many Western countries and some of the affectedAfrican nations. More then 5 million acres have been dusted with locust-killing chemicals; another 5 million will be treated by the end of June.
On May 30, representatives of Tunisia,Algeria, Libya, Morocco and Mauritania will meet inAlgiers to discuss tactics to wipe out the ravenous swarms. The move is an important step, but whatever plan is devised, the locust plague promised to get worse before the insects can be brought under control.
The purpose for affected nations to meet inAlgiers on May 30 is ______.
A、to devise antilocust plans
B、to wipe out the swarms in two years
C、to call out for additional financial aid from other nations
D、to bring the insects under control before the plague gets worse