MANHATTAN, Kansas — 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.