Both products are helpful tools for caterpillar control. In cole crops, cabbage maggot activity has been observed in many areas. Recent rainfalls and cool temperatures are ideal conditions for cabbage maggot egg and larval survival. Flea beetle activity continues to be brisk this week in New York, Ohio, Quebec, Illinois and Ontario. The threshold for flea beetles is 1 flea beetle per plant up to the 6th true leaf stage.
Radishes have a lower tolerance however if the tops are also being sold.
On early transplants, growers should also monitor carefully for the presence of Rhizoctonia disease which causes 'wirestem' symptoms and damping-off as well as Alternaria spot and downy mildew disease. Aster leafhopper numbers continue to be low in most areas of southern Ontario on celery, carrots and lettuce. Regular sweeping is needed to ensure that both local and long-distance migrations into fields is not missed. Carrot weevil activity has almost wrapped up in many areas. Control measures are taken at the 3rd leaf stage, however monitoring the movement prior to this determines whether controls are needed or not.