Whiteflies (Bemisia tabaci) threaten food security throughout the developing world. These insects attack staple crops like cassava, beans, and tomatoes by transmitting destructive plant viruses as they feed on the plants’ sugar-rich sap. Their sap-heavy diet poses some tricky challenges that existing “gene knockdown” approaches to sustainable pest management haven’t solved. The researchers plan a new strategy by engineering tomato plants so that when whiteflies suck up the sap, they dehydrate and die. This advance promises a safe, pesticide-free method for fighting whiteflies and other sap-eating pests.