Normally it takes four weeks for hoppers to become adults, but when the conditions are right as now their development switches to the fast track. As the vegetation in one place begins to run out the winged adults release pheromones - scent messages, which tell others in the group that they must move on. And when groups merge, they form a swarm. An adult locust eats its entire body weight every day, and a whole swarm can consume literally hundreds of tonnes of vegetation. They have to keep on moving. Swarm travels with the wind. It's the most energy-saving way of flying.


通常一只若虫需要经过4周才能变为成虫，但如果条件适宜，比如像现在，它们的生长速度会加快。一个地方的植物吃光之后，长翅膀的成虫会释放信息素，用味道告诉同伴说必须离开了。集中在一起之后，它们就形成蝗虫群，一只成年蝗虫每天的食量相当于自己的体重。一个蝗虫群每天可以吃掉几吨植物，它们必须不断迁移。蝗虫随着风迁移，这是最省力的飞行方式。