Despite major control and prevention operations, substantial crop losses have already occurred in the Amhara and Tigray regions of Ethiopia. The hopper bands (young locust populations moving together) have covered nearly 430 square kilometres and have consumed about 1.3 million metric tonnes of vegetation over a two-month period. The formation of bands is ongoing in the rangelands of the Ethiopian Somali Region; and massive new swarms will arrive from Yemen and Somalia.A swarm even forced an Ethiopian passenger plane off course in December.[29]