Status of aster leafhoppers
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.
Scouts are reporting low numbers of aster leafhoppers (3-7 per 100 sweeps) in celery and carrot fields in western Michigan. (See table for more areas.)
MSU Diagnostic Services has recently tested populations from the following sites for aster yellows: |
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Date |
Site |
Crop |
% Infectivity |
Treatment Threshold (ALH per 100 sweeps) |
June 20 |
S. E. Ottawa Co. |
Celery |
1.6% |
0 |
June 15 |
Newago Co. |
Celery |
0% |
35 |
June 20 |
Oceana Co. |
Carrots |
0% |
50 |
June 20 |
Allegan |
Celery |
0% |
35 |
Currently, few fields will have aster leafhopper populations that are high enough to justify insecticide treatment. However, this situation could change quickly if weather patterns change and bring more aster leafhoppers into the state. In addition, eggs laid by adults early in the season have hatched and nymphs are feeding and developing. Once these nymphs become adults with wings, they have the ability to from field to field. Both these factors may result in higher aster leafhopper populations.