Brian Grimmett, Kansas News Service Manhattan — Ellen Welti has a Ph.D. in, essentially, grasshoppers. And yet she was still mystified about why the number of grasshoppers in a long-protected and much-studied patch of Kansas prairie was dropping. Steadily. For 25 years. After all, the grass that the springy bugs feast on had actually grown more robustly as it absorbed mounting levels of carbon dioxide in the atmosphere. So why were the grasshoppers faring increasingly worse? “We thought that this is a pretty nice habitat for grasshoppers,” she said. The insects dwell on the Konza Long-Term Ecological Research site. Their home sat in preserve, shielded from development, from farming, from just about everything people do to the planet.