Cucumber mosaic virus (CMV) has commonly infected snap bean fields in the midwestern and northeastern US since 2000. CMV is spread into snap bean fields by the soybean aphid, which was first detected in this region in 2000. Because no CMV-resistant snap bean cultivars are available and soybean aphid control in snap bean fields does not reduce the incidence of CMV, a solution to this problem has been a major concern for the snap bean industry. A promising solution is to plant commercially available CMV-tolerant varieties during the period that the risk for CMV is the highest. Thus, our efforts have focused on identifying CMV-tolerant varieties as well as the period during the season that is at highest risk for CMV. Over the past several years, we have observed a positive correlation between CMV incidence and soybean aphid adult dispersal in snap bean fields. Snap bean fields planted from mid-May through late June are rarely infected with CMV, while CMV is much more common in snap bean fields planted from late June through the end of July. Also, we found that the variety ‘Zeus’ shows complete tolerance to CMV. Therefore, planting ‘Zeus’ in fields after late June may significantly reduce the risk of yield loss by CMV.