Monitoring diamond-back moth in commercial crops 2019
As in 2018, several UK brassica growers are monitoring diamond-back moths in their crops using pheromone traps. The results will be summarised on this web page.
If anyone else would like to contribute monitoring data to this site please contact .
See also the Syngenta Brassica Alert which has information on pest activity in Lincolnshire crops.
A large influx of diamond-back moths arrived on the night of 11th-12th June. The influx appeared to be similar in size to the very large influx at the end of May in 2016 and reports were mainly from Eastern England. A further large influx arrived around 17th June (reported in Eastern England), another smaller influx around 24th June and a further influx around 28-29 June. There was another small influx around 29th July - observed in Scotland.
Growers should remain vigilant and monitor susceptible crops. In terms of control the caterpillars are likely to be resistant to pyrethroids. More information is available on the AHDB web site.
The table below summarises the numbers of moths captured in pheromone traps in commercial brassica crops plus other observations.
| Date | Location | Number of moths | Number of traps | Mean number of moths per trap |
| 7 October | Wellesbourne |
0 |
2 | 0 |
| 4 October | Lincolnshire |
0 |
4 | 0 |
| 4 October | Wellesbourne |
0 |
2 | 0 |
| 1 October | Wellesbourne |
0 |
2 | 0 |
| 27 September | Lincolnshire |
0 |
4 | 0 |
| 27 September | Wellesbourne |
0 |
2 | 0 |
| 24 September | Lincolnshire |
0 |
2 | 0 |
| 20 September | Wellesbourne |
0 |
4 | 0 |
| 20 September | Wellesbourne |
0 |
2 | 0 |
| 17 September | Wellesbourne |
0 |
2 | 0 |
| 16 September | Scotland (Fife and Angus) |
1 |
12 | <0.1 |
| 13 September | Wellesbourne |
0 |
2 | 0 |
| 13 September | Lincolnshire |
0 |
4 | 0 |
| 10 September | Wellesbourne |
0 |
2 | 0 |
| 9 September | Scotland (Fife and Angus) |
0 |
12 | 0 |
| 6 September | Lincolnshire |
0 |
4 | 0 |
| 6 September | Wellesbourne |
0 |
2 | 0 |
| 3 September | Wellesbourne |
0 |
2 | 0 |
| 2 September | Scotland (Fife and Angus) |
10 |
12 | 0.8 |
| 30 August | Lincolnshire |
10 |
4 | 2.5 |
| 30 August | Wellesbourne |
0 |
2 | 0 |
| 27 August | Wellesbourne |
0 |
2 | 0 |
| 26 August | Scotland (Fife and Angus) |
6 |
12 | 0.5 |
| 23 August | Lincolnshire |
0 |
4 | 0 |
| 23 August | Wellesbourne |
1 |
2 | 0.5 |
| 20 August | Wellesbourne |
2 There were also 2 moths on a total of 5 carrot fly traps |
2 | 1 |
| 19 August | Scotland (Fife and Angus) |
9 |
12 | 0.75 |
| 16 August | Lincolnshire |
2 |
4 | 0.5 |
| 16 August | Wellesbourne |
2 |
2 | 1 |
| 13 August | Wellesbourne |
2 There were also 3 moths on a total of 5 carrot fly traps |
2 | 1 |
| 12 August | Scotland (Fife and Angus) |
1 |
12 | <0.1 |
| 9 August | Lincolnshire |
8 |
4 | 2 |
| 9 August | Wellesbourne |
2 There were also 4 moths on a total of 5 carrot fly traps |
2 | 1 |
| 6 August | Wellesbourne |
3 There were also 2 moths on a total of 5 carrot fly traps |
2 | 1.5 |
| 5 August | Scotland (Fife and Angus) |
15 |
12 | 1.3 |
| 2 August | Lincolnshire |
2 |
4 | 0.5 |
| 2 August | Wellesbourne |
4 There were also 2 moths on a total of 5 carrot fly traps |
2 | 2 |
| 30 July | Wellesbourne |
0 There were also 3 moths on a total of 5 carrot fly traps |
2 | 0 |
| 29 July | Scotland (Fife and Angus) |
70 |
12 | 5.8 |
| 26 July | Lincolnshire |
2 |
4 | 0.5 |
| 26 July | Wellesbourne |
2 There were also 4 moths on a total of 5 carrot fly traps |
2 | 1 |
| 23 July | Wellesbourne |
2 There were also 5 moths on a total of 5 carrot fly traps |
2 | 1 |
| 22 July | Scotland (Fife and Angus) |
24 |
12 | 2 |
| 19 July | Lincolnshire |
Spalding 2 Old Leake 3 |
4 (2 per site) | 1.25 |
| 19 July | Wellesbourne |
0 There were also 8 moths on a total of 5 carrot fly traps |
2 | 0 |
| 15 July | Scotland (Fife and Angus) |
11 |
12 | 0.9 |
| 15 July | Wellesbourne |
3 There were also 7 moths on a total of 5 carrot fly traps |
2 | 1.5 |
| 12 July | Wellesbourne |
1 There were also 11 moths on 5 carrot fly traps |
2 | 0.5 |
| 12 July | Lincolnshire |
Spalding 5 Old Leake 49 |
4 (2 per site) | 13.5 |
| 10 July | Lancashire |
71 Caterpillars seen in crops |
5 | 14.2 |
| 9 July | Wellesbourne |
1 There were also 14 moths on a total of 5 carrot fly traps |
2 | 0.5 |
| 8 July | Scotland (Fife and Angus) |
25 |
12 | 2.1 |
| 5 July | Lincolnshire |
Spalding 6 Kirton 10 Old Leake 47 |
6 (2 per site) | 10.5 |
| 5 July | Wellesbourne |
2 There were also 7 moths on a total of 5 carrot fly traps |
2 | 1 |
| 4 July | Somerset and Devon |
29 on one trap over 8 days. Moths seen in most brassica fields |
||
| 2 July | Wellesbourne |
11 There were also 11 moths on a total of 5 carrot fly traps |
2 | 5.5 |
| 1 July | Scotland (Fife and Angus) |
46 |
12 | 3.8 |
| 28 June | Wellesbourne |
3 There were also 4 moths on a total of 5 carrot fly traps |
2 | 1.5 |
| 25 June | Lancashire |
70 |
6 | 11.7 |
| 25 June | Wellesbourne |
4 There were also 4 moths in total on 5 carrot fly traps |
2 | 2 |
| 25 June | Lincolnshire |
15 Larvae in crop at Spalding (5 seen) |
1 | 15 |
| 24 June | Scotland (Fife and Angus) |
64 |
12 | 5.3 |
| 24 June | Lincolnshire |
Old Leake - 30 (17-24 June) |
2 | 15 |
| 21 June | Wellesbourne |
6 There were also 12 moths in total on 5 carrot fly traps |
2 | 3 |
| 18 June | Lancashire |
58 |
5 | 11.6 |
| 18 June | Wellesbourne |
8 There were also 2 moths in total on 3 carrot fly traps |
2 | 4 |
| 17 June | Scotland (Fife and Angus) |
29 |
12 | 2.25 |
| 14 June | Wellesbourne |
15 There were also 29 moths in total on 3 carrot fly traps |
2 | 7.5 |
| 12 June |
Lincolnshire |
2 (Kirton), 2 (Spalding) Larvae in crop at Spalding (14 seen), moths in crop at Old Leake. |
4 | 1 |
| 11 June |
Lancashire |
27 |
6 |
4.5 |
| 11 June |
Wellesbourne |
2 |
2 |
1 |
| 10 June |
Scotland (Fife and Angus) |
55 |
12 |
4.6 |
| 7 June |
Somerset and Devon |
9 (on 1 trap over 2 weeks) |
4 |
2.25 |
| 7 June |
Wellesbourne |
1 |
2 |
0.5 |
| 4 June |
Lancashire |
27 (16 at one site) and moths in crops |
6 |
4.5 |
| 4 June |
Wellesbourne |
0 |
2 |
0 |
| 3 June | Scotland (Fife and Angus) |
88 |
12 |
7.3 |
| 31 May |
Wellesbourne |
0 |
2 |
0 |
| 27 May |
Lancashire |
18 |
6 |
3 |
| 27 May |
Scotland (Fife and Angus) |
134 |
12 |
11.2 |
| 27 May |
Wellesbourne |
0 |
2 |
0 |
| 24 May |
Wellesbourne |
2 |
2 |
1 |
| 23 May |
Lincolnshire |
Moths seen in crops since 17th May |
- |
|
| 21 May |
Lancashire |
11 |
6 |
1.8 |
| 21 May | Wellesbourne |
0 |
2 | 0 |
| 20 May | Scotland (Fife and Angus) |
19 |
12 | 1.6 |
| 20 May |
Scotland |
Moths seen in crops |
- | |
| 17 May |
Wellesbourne |
1 |
2 |
0.5 |
| 14 May | Wellesbourne |
0 | 2 | 0 |
| 14 May |
Lancashire |
14 | 6 | 2.3 |
| 14 May |
Cornwall |
1 |
2 |
0.5 |
| 13 May | Scotland (Fife) |
0 |
4 |
0 |
| 10 May | Wellesbourne |
0 |
2 |
0 |
| 7 May |
Lancashire |
15 |
6 |
2.5 |
| 7 May | Wellesbourne |
0 |
2 |
0 |
| 3 May | Wellesbourne |
0 |
2 |
0 |
| 30 April |
Lancashire |
1 |
2 |
0.5 |
| 30 April |
Wellesbourne |
0 |
2 |
0 |
This activity is supported by the participating growers, FMC and AHDB.
Disclaimer
While the University or Warwick and the Agriculture and Horticulture Development Board seek to ensure that the information contained within this document is accurate at the time of production, no warranty is given in respect thereof and, to the maximum extent permitted by law, these organisations accept no liability for loss, damage or injury howsoever caused (including that caused by negligence) or suffered directly or indirectly in relation to information and opinions contained in or omitted from this document.
Because of the biological nature of the work it must be borne in mind that different circumstances and conditions could produce different results. Therefore, care must be taken with interpretation of the results, especially if they are used as the basis for commercial product recommendations.
