Possibilities of risk forecasting for the carrot fly (Psila rosae Fab., Diptera, Psilidae) in the south of France

Abstract: In France, as in northern Europe, the carrot fly is an important pest of Apiaceae cultures (carrots, celeriac, parsnips…). This pest takes on a new importance with the reduction of active ingredients available to growers for crop protection.Research is being conducted on risk forecasting models, in particular the German model SWAT. Unfortunately, SWAT does not yet allow a suitable forecast of the risks under the conditions of southwest France: first flight predicted too early and flight predicted for June-July not observed; overwintering in the form of larvae and not in the form of pupae in the more northern zones. Lastly, with the strong thermal amplitudes observed, it is necessary to take into account the values of maximum temperatures after the first flight for the evaluation of the second flight, which occurs in autumn.