General locations he visits every year include Rome City area in N.E. Indiana, Toledo area, Irish Hills in S. E. Michigan, Kellogg Forest near Battle Creek, Michigan, Calumet area S. of Chicago, Joliet, IL and Quad Cities area. All these have abundant buckthorn available for overwintering. He found active aphid colonies at about half of these locations. He was surprised to see aphids because of the cool weather in the midwest so far. This is one of his pictures from a couple years ago, showing a spring colony on buckthorn being tended by aphids.
It won't be long before migratory aphids are moving to soybean. Even though it was an extremely low aphid year in 2010, we don't know what will happen this year if conditions are conducive to their growth potential. I'll keep you posted as regional information is shared.