Thursday, 28 May 2020

Aster leafhopper

This year the Victoria day long weekend came early (May 16-18, 2020), and so did two of our annual, migratory pests. While the PPMN tracks forward and backward trajectories of high air masses originating in the southern part of North America and arriving to points across the Canadian prairies, the provincial ministries of Alberta, Saskatchewan, and Manitoba coordinate province-wide diamondback moth (DBM) trapping to detect the initial appearance of DBM.  Traps include a pheromone lure used to entice male DBM to a sticky death in order to monitor their arrival across the Canadian prairies.

Early arriving DBM can reproduce on volunteer cruciferous weeds then move to canola as that crop emerges and grows in the spring. This can lead to population increases through the growing season. In some areas of Canada, DBM can produce up to five generations before the winter cold brings an end to their populations.

Recently, AAFC scientists supported by WGRF, have been matching these wind trajectories with the arrivals of DBM and another migratory pest, the aster leafhopper.  The aster leafhopper spreads aster yellows disease, primarily to canola, and can have up to three generations in Canada. AAFC scientists have recently developed a rapid test to determine if an aster leafhopper is infected with aster yellows. In 2020, the COVID-19 pandemic lockdown prevented us from estimating the percentage of infected aster leafhoppers and gaining a better understanding of the risks of aster yellows transmission. Aster leafhoppers and DBM have migrated into Saskatchewan and might also be in Alberta and Manitoba.

Contact Dr. Chrystel Olivier and Dr. Tyler Wist to find out more about the above aster leafhopper  project.