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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 rosemary dot collier at warwick dot ac dot uk.

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
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.

 

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