The document discusses challenges for crop protection and managing pests with fewer pesticides. It notes that factors like climate change, less crop diversity, and broad spectrum pesticides can promote pest issues. The document advocates for integrated pest management approaches that combine host plant resistance, biological control, and targeted pesticide use. It provides examples of ongoing research into alternatives like pheromone monitoring systems, resistant varieties, and lure-and-kill technologies using aggregation pheromones and entomopathogenic fungi. The conclusion calls for more diversified and preventative strategies through professional agronomy support and information sharing.

1. Rothamsted Research
where knowledge grows
Rothamsted Research
where knowledge grows
Managing Pests with Fewer
Pesticides
Toby Bruce

2. “High yielding varieties”

3. really ?

4. Toby J. A. Bruce J. Exp. Bot. 2012;63:537-541
© The Author [2011]. Published by Oxford University Press [on behalf of the Society for
Experimental Biology]. All rights reserved. For Permissions, please e-mail:
journals.permissions@oup.com
Factors influencing crop protection in an agro-ecosystem

5. Bruce (2011) J. Exp. Bot. 63: 537-541
fewer
effective
pesticides
legislation
reduced
discovery
and approval
of new
products
Factors influencing crop protection in an agro-ecosystem

6. fewer
effective
pesticides
reduced
genetic
diversity
in crops
THRIVING
PESTS AND
HIGH CROP
LOSSES
climate change can
make conditions
better for pests
less intrinsic resistance
to insects and
pathogens, and less
competitiveness with
weeds
fertilised crops more
nutritious to insects
and pathogens
broad spectrum
pesticides kill
natural enemies
of pests
Bruce (2011) J. Exp. Bot. 63: 537-541
Factors influencing crop protection in an agro-ecosystem

7. Promoting
IPM and use
of
alternatives
2009/128/EC on the Sustainable Use of Pesticides
Reducing risks
and impacts of
pesticide use on
human health
and environment
Development of “Alternatives” is urgently
needed

8. Development of “Alternatives” is urgently
needed

12. Why is it needed?

13. Will future demand be met?
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
10000000
1961 1966 1971 1976 1981 1986 1991 1996 2001 2006 2011 2016 2021 2026 2031 2036 2041 2046
Population(1000s);CerealProduction(x500tonnes)
Source: FAOSTAT
Bruce (2010) Food Security 2: 133-141
To keep pace with
growing demand,
global food
production needs
to increase by an
estimated 70% by
2050 [United
Nations]

14. New directions for 21st Century Agriculture
Royal Society: “There is a pressing
need for the ‘sustainable
intensification’ of global agriculture in
which yields are increased without
adverse environmental impact and
without the cultivation of more land”.
Royal Society (2009) Policy document 11/09
A second green revolution which is knowledge intensive
rather than input intensive?

15.  Agronomy
 Resistant crops
 Enhancing Biocontrol
 Improved targetting
 RNAi
 Information and data sharing
 Improved targeting
 Intelligent agriculture
Crop protection from pests – new directions are needed

17. Integrated Pest Management (IPM)
host plant
resistance
IPM
biological
control
pesticides
Tactics are more effective when used in combination and
resistance is less likely to evolve

18. Biological control of pests - either by release in glasshouses or
encouraging natural populations outside.

19. Biocontrol
• Proven success in greenhouses with artificial release
• Conservation biocontrol strategies needed in outdoor
cropping environments
– Growth rate and arrival rate slower than pests
– Can arrival be speeded up?

20. Biocontrol in edible protected crops 2010/11
(UK)
Aphidius ervi used on 2072 ha:
350 ha tomatoes,
131 ha of cucumbers,
1511 ha of peppers
Data from Fera Pesticide Usage survey (ha are treated hectares and include repeat
treatments)
Aphidius colemani used on 3160 ha:
2235 ha peppers,
487 ha of cucumbers,
426 other vegetables

21. Conservation biocontrol: preserving what is already out there

22. Biocontrol opportunities
 Develop attractants for natural enemies as part of an IPM
strategy (lure and reward)
 Develop attractants for pests as part of an IPM strategy
(lure and kill)

23. Orange wheat blossom midge

24. Resistant varieties
Oakley et al 2005 HGCA Project Report No. 363
Now approx. 60% of UK wheat is resistant

25. Resistant varieties
• Females lay eggs, but
larvae die when they start
to feed
• A wound plug is formed at
the feeding site due to
lignification
• Antibiotic action of
phenolic acids by the grain

26. Wound plug

27. Lignification process

28. OCOC3H7
OCOC3H7
2,7-nonanediyl dibutyrate
Sex pheromone

29. Monitoring systems
• Allow rational use of pesticides
• Need based applications save costs
and importantly slow down the
development of resistance
• sex pheromone traps:
- provide a solution to the
detection problem
- enable more accurate and
effective spray timing
Bruce et al. (2007) Pest Man. Sci. 63: 49

30. Bruce et al. (2007) Pest Man. Sci. 63: 49
pheromone traps are now
commercially available to wheat
growers in the UK
Monitoring systems

31. Is wheat at the ear
emergence growth
stage?
NO
YES
Check pheromone
traps. Are catches
> 30 per day?
Is it at an earlier
stage?
Check traps
later when
boots split
Crop is no longer
vulnerable when
flowering starts.
Collect in traps
Keep
checking
traps daily
until
flowering
starts…
Treat wheat fields in the
surrounding area as soon as
possible (females can fly to
other nearby fields).
Are you growing a
midge resistant variety?
YES
NO
No further
action needed
(i.e. no need
for monitoring
traps or
insecticide
treatment)
Pheromone traps need to be put up before ear emergence in fields
where wheat was grown in previous years – these fields are sources
of the pest [if growing susceptible varieties].
YES
NO
NO
YES
Are catches > 120 per day
NO
YES
Assess wheat ears in
field in evening. Spray if
>1 midge on 6 ears
Wheat midge decision support

32. Web-based spray forecasting system
incorporating MET data and crop growth stage

33. http://www3.syngenta.com/country/uk/en/
AgronomyTools/Pages/BruchidCast.aspx

36. You get this
twice a week
during the
season

40. 4-Methylheptane-3,5-dione
Beauveria bassiana spores adhering to
Entostat particles
Sitona lineatus
adults
♂ produced
aggregation
pheromone that
attracts ♀s and
♂s
Team: Toby Bruce (PI), Lesley Smart, Janet Martin
Lure-and-kill of pea and bean weevil, Sitona lineatus

41. The Lure: Aggregation pheromone: 4-methyl-3,5-
heptanedione
• Male produced
• Attract both sexes of Sitona lineatus
• Monitoring system: pheromone-based traps
(Blight et al., 1984; Glinwood et al., 1993)
The killing part: Entomopathogenic fungus:
Beauveria bassiana
• Naturally present in the soil
• Known to kill S. lineatus insects, when infected
(Feng et al., 1994; Maurer et al., 1997; Poprawski et al., 1988)
4-methyl-3,5-
heptanedione
Monitoring trap
Lure-and-kill technology:
1. The aggregation pheromone & the pathogenic fungus
combined in a device
2. The attracted insects will be coated with spores of the
fungal disease
3. When they leave the device, the weevils will spread the
pathogen to others insects of the same species
Lure-and-kill of pea and bean weevil, Sitona lineatus

42. Field testing lure formulations
42
0
20
40
60
80
100
120
140
160
180
total/4traps
A = Blank B = standard lure C = synthetic 1%
D = synthetic 3% E = natural 1% F = natural 3%
 Treatment F traps
was the most
effective lure
 Traps were able to
attract weevils during
the whole trial period
whereas the lure’s
release rates were
only measurable for 2
days in the lab

43. Mortality assessment with Beauvaria bassiana formulations
43
0
10
20
30
40
50
60
3-5
jun
5-8
jun
8-11
jun
11-15
jun
15-19
jun
19-23
jun
Control Entostat 1g INS 0.5g
B1 2g B1 0.633g B1 0.2g
B1 0.063g B1 0.02g
0
10
20
30
40
50
60
3-5 jun5-8 jun 8-11
jun
11-15
jun
15-19
jun
19-23
jun
Control Entostat 1g INS 0.5g
B2 2g B2 0.633g B2 0.2g

44. =
Team: Toby Bruce (PI), Jon West, Stephen Moss
http://croprotect.com/

45. TARGET MENTIONS
Aphid 35
Slugs 32
Black grass 30
septoria 27
yellow rust 19
cleavers 16
cabbage stem flea beetle 15
light leaf spot 15
fusarium head blight 14
annual meadow grass 13
brome 13
charlock 13
phoma 13
pollen beetle 12
sclerotinia 12
wild oats 12
chocolate spot 11
brown rust 10
dock 10
early blight (alternaria) 10
bruchid beetle 9
chickweed 9
Nematodes 9
net blotch 9
rhynchosporium 9
cranesbill 8
leatherjackets 8
pea & bean weevil 8
powdery mildew 8
barley yellow dwarf virus (BYDV) 7
broad leaved weeds (generic BLW) 7
crown rust 7
late blight (phytophthora) 7
mayweed 7
orange wheat blossom midge 7
ryegrass 7
thistles 7
turnip yellows virus (TuYV) 7
downy mildew 6

50. Big data – the power of mapping in time and space
Hugh Oliver-Bellasis, 3 Nov 2015

51. Resistant crops

52. Labandeira (2013) Curr. Opin. Plant Biol. 16: 414
400 Million years of
Coevolution
Agriculture can learn lessons from the wild plants and ecosystems

53. Conclusions – what to do?
Crop protection is becoming increasingly difficult - but
that means farmers need professional agronomists even more!!
• Diversify crops and protection strategies
– Not just pesticides – more IPM
– Include resistant crop cultivars
– Use biocontrol more
– Prevention instead of cure?
• Monitor pests/weeds/diseases
– Expect rapid developments in surveillance systems
• Share information
 www.croprotect.com