Aphids Spreading Viruses

 A surprising surge in damage in pea fields across the Palouse shows both the merits and the difficulties in predicting when aphid-borne viruses might cause problems, a University of Idaho entomologist said. Dr. Sanford Eigenbrode, professor and division chair of entomological sciences in the College of Agricultural and Life Sciences, said the Aphid Tracker network of monitoring stations tries to assess the risk of disease-caused crop losses in cool season legumes including peas and lentils: “One of the most difficult problems facing agriculture are viruses that cause diseases and worldwide their problems and most viruses require some vector to get from plant to plant and most of those vectors are aphids.”

The Aphid Tracker network has 30 sampling stations, each with aphid traps that are emptied twice weekly. The traps track the timing of aphids' appearance and their number throughout the season, and they are analyzed for signs of virus. Although still in development, this information is intended to provide an early warning system about the risk of virus diseases.

The study at the college's research center near Moscow is revealing some fundamental information about  the effects of virus infections on crop yields. Pea plants have been exposed to aphids and viruses at 3-day intervals since the plants began growing this spring. Plants infected within days after sprouting are now dead. Other pea plants exposed later show symptoms but survived. The closer to the end of the plant's growth when infection occurred, the less damage to the crop is likely.