OWBM

Question 1

Last major outbreak of OWBM

Answer 1

3-5 year outbreaks but the last one was in 2004, where 1 million tonnes of wheat was lost

Question 2

Out breaks are…

Answer 2

Serious but sporadic, they’re sporadic due to specific growth stages.

Question 3

Crops are at most risk if..

Answer 3

Peak adult emergence coincides with GS53-59

Question 4

What crops can OWBM be found in

Answer 4

Wheat, barley, oats, sometimes in grass, often occurring with leather jackets

Question 5

Sprayed?

Answer 5

They’re prophylactically sprayed but problematic with non targets

Question 6

3 reasons of Importance

Answer 6

1. Larvae feed on developing grain- grain shrivelling although signs of other problems it’s a good indication of OWBM.
2. Poor germination
3. Impacts of grain yield and quality

Question 7

Importance with secondary problems

Answer 7

Grain lost through secondary problems- damage to outer grain layer, facilitating water entry and causes sprouting and secondary fungal attacks

Question 8

3 examples of prevention

Answer 8

Crop rotations
Break crops
Resistant varieties

Question 9

Crop rotations

Answer 9

Problematic since impractical to have 10 year rotations due to survival of larvae as cocoons in the soil

Question 10

Break crop example

Answer 10

OSR can reduce soil population

Question 11

Resistant varieties examples

Answer 11

From group 1: Skyfall
New ones include: Prince, merit or illuminate

Question 12

Localised pest

Answer 12

They fly but not far, females can fly into nearby fields so treatment should include surrounding wheat fields

Question 13

Identify OWBM

Answer 13

Both adult/larvae are orange

Question 14

What are adult OWBM similar to

Answer 14

Yellow blossom midge

Question 15

What are OWBM larvae similar to

Answer 15

Sandal gaul midge larvae

Question 16

How do you know it is OWBM and not sandal gaul midge

Answer 16

Sandal haul midge is more sporadic (not had an outbreak for 30 years) so assume it’s OWBM

Question 17

Correct identification is…

Answer 17

Crucial to IPM success

Question 18

4 examples of detection

Answer 18

1. Pheromone trapping
2. Crop inspections
3. Sticky traps/spider webs
4. Sample when cultivating

Question 19

Pheromone trapping

Answer 19

Placed in fields where OWBM was recorded the previous year. Most recommended

Question 20

How often should you change pheromone traps

Answer 20

Replace every 3 weeks for efficiency

Question 21

When should pheromone traps be set out

Answer 21

Set traps at GS 45 which is the flag leaf sheath swollen, leave trap in situ until GS 61 (flowering)

Question 22

How often should you check pheromone traps

Answer 22

Cheeky daily

Question 23

Crop inspections should be done at

Answer 23

On the evening when they are more active and flying, but this is impractical and you can double count individuals

Question 24

Sampling benefits

Answer 24

Targets larvae and pupae, provides info on pest development, provides early warning

Question 25

Sampling drawbacks

Answer 25

Expensive to conduct

Question 26

Stick traps info

Answer 26

Put out at the start of ear emergence, does not monitor pupae or larvae, unreliable, targets adults not larvae

Question 27

Action thresholds: soils sample

Answer 27

Pupae recorded- more than 11/kg soil

Question 28

Action thresholds: sticky traps

Answer 28

Adults recorded: more than 10/trap/day

Question 29

Action thresholds: crop inspection

Answer 29

Adults recorded: more than 1/6 ears sampled

Question 30

Action thresholds: pheromone trapping

Answer 30

Adults recorded: more than 30/trap/day - present a general risk- monitor
More than 120/ trap/ day presents high risk- treat susceptible crops

Question 31

What are the 4 natural enemies of OWNM

Answer 31

Dance flies
Spiders (webs)
Ground beetle
Parasitic wasp

Question 32

What do the 4 natural enemies target

Answer 32

Dance flies- feed on adults
Spiders- webs traps adults
Ground beetle- feed on larvae
Parasitic wasp- attack larvae+ prevent pupation

Question 33

What should we promote for natural enemies

Answer 33

You can’t buy, but promote naturally occurring: beetle banks, avoid bros spectrum pyrethroids, flower rich margins good for all but especially for ground beetles- providing pollen and supplementary nutrition

Question 34

Chemical controls for OWBM

Answer 34

Chlorpirifos which is an organophosphate and targeted eggs, larvae and adults but no longer approved for use in the UK. Now the most commonly used one is Lamda-sialothrin which is a purethroid and grafted adults

Question 35

Problem with natural enemies

Answer 35

Incompatible with one another

Question 36

Favourable temperatures for OWBM

Answer 36

Warmer temps, 10 degrees plus, generally humid for pupae to emerge into adults.

Question 37

Problems with wild flower margins

Answer 37

They’re effective but costly, there’s not much information on species of wildflower promoting natural enemies, most of the current effort is on bees, won’t find many pre made mixes for natural enemies

Question 38

What might you do if action threshold is detected ?

Answer 38

If you grow a resistant variety, no action is required an no need to monitor or apply insecticide, otherwise….
set up traps prior to ear emergence as these are the sources of pests…..
If wheat is at ear emergence stage check traps, the crop is no longer vulnerable when flowering starts…

Question 39

What might you do if action threshold is met… continued

Answer 39

If ear is at emergence.. if catches are over 30 trap/day continue to check but if over 120 trap/ day treat wheat and surrounding fields

Question 40

Action threshold for feed wheat

Answer 40

1 midge on three ears

Question 41

Action threshold for milling wheat/seed crop

Answer 41

1 on 6 ears

Question 42

Problems with beetle banks

Answer 42

Beetles move into headlands of field but not that effective in the centre- talk on beetle banks in the middle- problems with spraying- equipment sizes, cost etc