MONITORING AND FORECASTING ATTACKS OF CABBAGE ROOT FLY AND CARROT FLY IN VEGETABLE CROPS

S. Finch, R. H. Collier
Laboratory and field experiments indicated that the number of day-degrees /D°/ required for the cabbage root fly to complete a generation was approximately 580 D° above a base temperature of 6 °C, measured at a soil depth of 6 cm. The times to 10 % oviposition by this fly could be forecast as accurately using D° accumulated on integrating thermometers as using D° calculated from data collected at a nearby weather station.

The original forecast was based solely on accumulated D°. Apart from the over-riding influence of temperature, however, cabbage root fly activity in the field is influenced considerably by a/ the times the flies emerge from the overwintering puparia, b/ aestivation and, c/ the effect of day-length. By including these 3 factors, both seasonal and local variations in cabbage root fly infestations can be forecast with satisfactory accuracy.

A comparable system is being developed for the carrot fly.

Finch, S. and Collier, R. H. (1988). MONITORING AND FORECASTING ATTACKS OF CABBAGE ROOT FLY AND CARROT FLY IN VEGETABLE CROPS. Acta Hortic. 219, 39-46
DOI: 10.17660/ActaHortic.1988.219.6
https://doi.org/10.17660/ActaHortic.1988.219.6

Acta Horticulturae