Which of the following insects is a common vector of plant viruses:

• A. Grubs
• B. Aphids
• C. Moths
• D. Flies

Answer: (B)

Plant viruses are spread mainly by insects that feed on plant sap and move from plant to plant as they probe and feed. Aphids are the best answer because their piercing-sucking mouthparts take up virus particles from an infected plant during brief feeding probes and they can rapidly disperse to healthy plants, spreading many types of viruses. They are capable of transmitting viruses in both non-persistent and persistent ways, and their numbers and ability to fly make them frequent and efficient vectors in fields and gardens. Grubs are root-feeding larvae and don’t typically transmit viruses between living plants. Moths and flies aren’t considered the common vectors for plant viruses in crop situations.