Our potato research and outreach program focuses on economically controlling the insects that hinder potato production in Minnesota. Our studies focus on both common and emerging pests in potato production, including the insect vectors of potato virus Y (PVY), potato leaf roll virus and Purpletop and long-standing insect pests such as Colorado potato beetle. We work closely with other researchers and growers in Minnesota and North Dakota to provide the most up-to-date information on potato insects and how to effectively manage them.
Aphid Vectors of Potato Virus Y (PVY)
The prevalence of PVY has changed over recent years and is now one of the most important diseases in potato production nationally. These viral diseases require transmission by pathogen-carrying aphids, or vectors. In addition to a number of indigenous aphids, a new invasive species (i.e., the soybean aphid), has played a significant role in increasing rates of transmission. New asymptomatic strains of the virus, PVYNO, PVYN and PVYNTN, which can cause tuber necrosis, have also played a role in this increasing epidemic. These factors make PVY a concern in both the commercial and seed potato production industries.
Movement of PVY inoculum involves a number of aphid vector species. Potato virus Y is a non-persistent virus, meaning an aphid can become infected almost immediately upon feeding on an infected plant and can, in turn, immediately infect the next plant upon which it feeds. Consequently, the spread of PVY within a seed field can occur rapidly.
There are a number of well-established strategies in managing PVY, one of which is vector control. This involves the use of crop oils and insecticides that reduce feeding and probing behaviors of the aphid vectors. The application of these management techniques requires appropriate timing to be effective.
To help growers manage vector populations, we established a series of aphid suction traps in 20 locations in Minnesota and North Dakota. With the assistance of grower cooperators, trap catches are gathered weekly and sent to the entomology laboratory at the NWROC. We identify aphid species in all location samples and share the weekly counts with potato producers via ListServes, weekly email updates through the Northern Plains Potato Growers Association and via blogs (i.e. aphidalert.blogspot.com/ and aphidalert.umn.edu).
These weekly reports provide growers with information on when to start the application of management tactics. The updates also provide insight into the regional population dynamics of aphid vectors. For example, certain species of aphids are more efficient at spreading PVY than others and post a much greater risk. Our reports incorporate the PVY vector risk index for each type of aphid, so growers know which species of aphids they need to respond to at what population levels.
- Ian MacRae, (218) 281-8611 or firstname.lastname@example.org