A radio station in Senegal is offering listeners a 50 kg sack of rice if they can catch and kill 50 kg of locusts, another new tactic in West Africa's battle against the airborne invasion. "We launched this idea to get more people involved in the war on locusts," said Abdoulaye Ba, a business manager at radio station Sud-Fm in the northern town of Saint Louis, capital of one of Senegal's worst affected regions. West Africa's first locust plague in 15 years is destroying vast swathes of crops in communities where many are subsistence farmers and where the authorities lack the means to spray pesticide quickly enough to stop the swarms spreading. Senegal's traditional soothsayers have urged people to make sacrifices of boiled cereal and curdled milk to fight the plague, while in neighbouring Mali radio listeners have been told to burn, drown or stamp on the insects. Asked what the radio station would do with sacks full of dead locusts, Ba said: "They are full of protein. Perhaps they could be turned into food for livestock."