Springstar Oak Stump Aphid Chaser S512 Ward off pest aphids on roses with a natural pheromone that alarms aphids and caused them to stop feeding and eventually move on or die of starvation Non-toxic dispensers do not affect beneficial insects and control most prevalent aphids typed, especially Green Peach Aphid, the most common species that attacks roses One dispenser hung on each infested rose plant wards off aphids in 5 to 7 days Dispenser works for three to four weeks Apply dispensers early in the season to prevent aphid colonies from becoming established