What effect will the winter weather have on crop pests? This was one of the most common questions asked by participants during the recent Crop Advantage Series meetings. And no insect, except maybe the corn rootworms, causes greater concern than the soybean aphid. We know that soybean aphids overwinter in the egg stage on common buckthorn and alder-leaf buckthorn. The eggs are laid on or near leaf buds on young plants and are therefore exposed to cold winter air unless they are covered by snow.