ROME (AP) - Locusts that have covered up to 22 million acres in Kazakstan have spread into Russia, infesting some regions for the first time since the 1920s, the U.N. Food and Agriculture Organization said Thursday. The locusts are thriving on land left fallow because of the poor economic conditions in the former Soviet republics, the Rome-based FAO said. In almost all regions, authorities lack the pesticides and other resources to check the swarms. The locusts have laid eggs on up to 22 million acres in Kazakstan, posing a major threat to next year's crops in that country and surrounding ones. Swarms have spread across the border into Russia, covering more than 2.47 million acres.