Carrot fly forecast 2025
The forecast outputs below are based on weather data provided by Agrii. The forecasts predict the timing of fly activity. They do not predict the number of insects present in the crop, as this depends on the size of the local fly population. For control purposes, we consider that the pest has become active when 10% of the insects have emerged/laid eggs and that the peak of activity has occurred when 50% have emerged/laid eggs. The predictions will change over time depending on weather conditions.
At the moment third generation carrot fly emergence is likely to start in the second week of September at the warmest sites.
Updated 29 September 2025
| Location |
First generation 10% eggs |
First generation 50% eggs |
Second generation 10% emergence |
Second generation 10% eggs |
Second generation 50% eggs |
Third generation 10% emergence |
|---|---|---|---|---|---|---|
| Cornwall - Hayle |
28 Apr | 11 May | 19 Jul | 28 Jul | 9 Aug | 11 Oct |
| Kent - Sandwich |
30 Apr | 14 May | 5 Jul | 14 Jul | 25 Jul | 12 Sep |
| Suffolk - Ipswich |
3 May | 15 May | 10 Jul | 18 Jul | 30 Jul | 16 Sep |
| Warwick, Wellesbourne |
30 Apr | 16 May | 4 Jul | 12 Jul | 27 Jul | 10 Sep |
| Norfolk, Norwich |
5 May | 18 May | 12 Jul | 20 Jul | 1 Aug | 21 Sep |
| Lincolnshire - Holbeach |
30 Apr | 14 May | 12 Jul | 18 Jul | 30 Jul | 22 Sep |
| Nottingham - Stubton |
27 Apr | 10 May | 4 Jul | 10 Jul | 27 Jul | 10 Sep |
| Lancashire, Southport |
1 May | 19 May | 14 Jul | 18 Jul | 1 Aug | 29 Sep |
| Yorkshire, York |
1 May | 15 May | 6 Jul | 14 Jul | 27 Jul | 15 Sep |
| Perthshire, Scotland |
5 May | 20 May | 19 Jul | 27 Jul | 11 Aug | - |
