ABSTRACT
Cutworm attacks in Denmark vary greatly from year to year. Hence forecasting is important as background for and economic handling of this pest problem. A monitoring system based on sex traps has been developed through the years to obtain the necessary information about the pest. Despite the fact that the catches of the turnip moth have not corresponded to the damage, it has been possible to issue reasonable forecasts. These forecasts were based on catch and weather conditions of importance for the development and mortality of the cutworms. The system has been improved, but further development is desirable. For this, however, more precise information on development and mortality factors have to be obtained experimentally in order to make a more realistic estimate of the change of populations from moths until 3rd instar larvae.
