Aster leafhopper and aster yellows test results
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
We have received results of tests on aster leafhoppers collected from celery fields in southwestern Michigan (Ottawa, Allegan and southern Newaygo counties) during July 15-19. None of these leafhoppers tested positive for aster yellows. We recommend a treatment threshold of 35 aster leafhoppers per 100 sweeps for these areas. The latest test results we received on leafhoppers collected from carrot fields in Oceana, Mason and Newaygo counties indicate higher infectivity. See the August 2 issue of the Vegetable CAT Alert for these treatment thresholds.