New Agreement Takes Aim at Potato Pest and its Disease-Causing Cohort

Developing a chemical attractant to monitor and manage the potato psyllid is the goal of a new cooperative agreement signed in March between the Agricultural Research Service (ARS) and the University of California (UC) at Riverside.

The potato psyllid, Bactericera cockerelli, causes harm to potato plants by feeding on them and by infecting them with Candidatus Liberibacter solanacearum, the bacterial culprit behind zebra chip disease. The name “zebra chip” refers to the dark stripes that form inside affected potatoes that are sliced and fried to make chips. Outbreaks of zebra chip fueled by psyllid feeding have caused millions of dollars in losses to the potato industries of the United States and Mexico. The disease also is problematic in New Zealand.

Spraying insecticide is the primary control method for preventing outbreaks of the psyllid and transmission of disease. But determining where and when to spray based on psyllid migration patterns or movements can be difficult, due to the lack of an effective monitoring tool. Besides ratcheting up production costs, ill-timed spraying can endanger beneficial insects and can increase the potential for the development of pesticide resistance by the psyllid.

Under a six-month cooperative agreement with UC entomologist Jocelyn Millar, ARS and university scientists will seek to isolate, identify, synthesize and test the specific chemical or chemicals that females use to attract mates.

According to entomologists David Horton and Christelle Guédot at the ARS Yakima Agricultural Research Laboratory in Wapato, Wash., synthesizing such attractants opens the door to developing a new, psyllid-specific monitoring tool. Strategically placed around potato fields, attractant-laced traps would enable growers to capture male psyllids and determine when the insects are colonizing fields. Growers could then plan insecticide regimens accordingly.

The agreement between UC-Riverside and ARS is a pooling of resources and personnel that leverages Millar’s research on insect chemical ecology with the Wapato team’s behavioral assay studies.

ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture (USDA). This research supports the USDA priority of promoting international food security.