Role of lygus bug in fruit deformity

IPM tools for managing lygus bug

Surendra Dara PhD, DAIT Strawberry and Vegetable Crops Advisor and Affiliated IPM Advisor

University of California Cooperative Extension San Luis Obispo, Santa Barbara, and Ventura Counties

skdara@ucdavis.edu

eNewsletters: ucanr.edu/strawberries-vegetables and ucanr.edu/pestnews Download the free iOS app “IPMinfo” about strawberry pests and diseases

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Central Coast Strawberry Meeting, Watsonville, 4 February, 2016

Strawberry fruit deformation

Strawberry fruit deformation Fruit deformity to due lygus bug damage

Deformity due to poor pollination, genetic, environmental, and other factors

Role of lygus bug on fruit deformation

• Conventional (18) and organic (10) fields • 9 Sampling dates

• 4 replications (different parts of the field)

• At least 100 deformed berries/replication

Role of lygus bug on fruit deformation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Conventional Organic

Percent deformity from lygus bug damage and other causes

Lygus Other

A B

b a

Tukey’s HSD at P = 0.0002

Conclusions

• In both conventional (59%) and organic (67%) fields majority of the deformity was related to lygus bug feeding

• Lygus-related damage was significantly higher in organic fields and damage due to other factors was significantly higher in conventional fields

• Sampling for lygus is the most reliable way to make treatment decision

Acknowledgements Grower Dave Peck, Manzanita Berry Farms Daren and Kevin Gee, DB Specialty Farms Technical assistance Fritz Light Tamas Zold

Decision making for pest management

Efficacy Economical

Resistance Management Sustainability

Decision

IPM Tools for Strawberries

Botanical Chemical

Microbial Mechanical

IPM

2015 Strawberry IPM trial Sundance Berry Farms, Santa Maria

Chemicals-Mode of action groups

3A Pyrethrins-Sodium channel modulators 4A Neonicotinoids 4C Sulfoximines 4D Butenolides 9C Flonicamid – Modulators of chordotonal organs 15 Benzoylureas - Inhibitors of chitin biosynthesis

Nicotinic acetylcholine receptor competitive modulators }

Non-chemical alternatives

• Entomopathogenic fungi, Beauveria bassiana, Isaria fumosorosea, and Metarhizium brunneum

• Botanical insect growth regulator, azadirachtin

• Mechanical removal - vacuuming

Azadirachtin mode of action

• Interferes with protein synthesis • Affects molting and metamorphosis • Disturbs mating and sexual communication • Sterilizes adults • Reduces reproductive ability • Acts as antifeedant and repellent

http://files.meistermedia.net/cpd/images/structures/largeview/azadirachtin.gif

Lygus bug management study 1st application (Rate/acre) 2nd application (Rate/acre) 3rd application (Rate/acre)

1 Untreated Untreated Untreated

2 Assail 70 WP (3 oz) 4A* Assail 70 WP (3 oz) 4A Assail 70 WP (3 oz) 4A

3 Vacuum Vacuum Vacuum

4 Rimon 0.83 EC (12 fl oz) 15 + Brigade (16 oz) 3A

Met52 EC(16 fl oz) + Debug Turbo (104 fl oz)

Met52 EC (16 fl oz) + AzaGuard (16 fl oz)

5 Sequoia (4.5 oz) 4C Sequoia (4.5 oz) 4C Vacuum

6 Pfr-97 (2 lb) + Neemix (9 fl oz)

Pfr-97 (2 lb) + Neemix (9 fl oz)

Vacuum

7 Vacuum Sivanto (14 fl oz) 4D + Debug Turbo (104 fl oz)

Rimon 0.83 EC (12 fl oz) 15 + Brigade (16 oz) 3A

8 Sivanto (14 fl oz) 4D Sivanto (14 fl oz) 4D Vacuum

9 Sequoia (4.5 oz) 4C Sivanto (14 fl oz) 4D Beleaf 50 SG (2.8 oz) 9C

10 B. bassiana+neem (1qrt) B. bassiana+pyrethrum 3A+neem (1qrt) B. bassiana+pyrethrum 3A (1qrt)

11 B. bassiana+pyrethrum 3A (1qrt) B. bassiana+neem (1qrt) Beleaf 50 SG (2.8 oz) 9C

12 B. bassiana+pyrethrum 3A (1qrt) Vacuum Rimon 0.83 EC (12 fl oz) 15 + Brigade (16 oz) 3A

*MoA group 4A Neonicotinoids 4C Sulfoximines 4D Butenolides

9C Flonicamid – Modulators of chordotonal organs 15 Benzoylureas - Inhibitors of chitin biosynthesis

3A Pyrethrins-Sodium channel modulators Nicotinic acetylcholine receptor competitive modulators }

Treatments and sampling

• Treatments applied on 26 August, 2 and 9 September, 2015 • Vacuuming was done twice a week only in vacuum treatments • Spray volume was 100 gpa for all treatments • Sampled 6 days after each application

Lygus life stages after three applications

0

10

20

30

40Pre-treatment Post-treatment

0

2

4

6

8

0

2

4

6

8

Young Nymphs

Old Nymphs

Adults

P = 0.012 a

b b

ab ab ab

ab

ab ab ab ab

ab

Num

ber/

20 p

lant

s

Change in lygus and natural enemy populations 78

8 12 8

71

33 27

-12

-29

86

47

0

-40

-20

0

20

40

60

80

100

147 63 17 21

289

867

125 42

350 289

0 143

0

200

400

600

800

1000

Perc

ent c

hang

e po

st-t

reat

men

t

Lygus bug

Natural enemies

Treatment efficacy Rank % Change I Spray II Spray III Spray

I -28.9 Sequoia (4.5 oz) 4C* Sivanto (14 fl oz) 4D Beleaf 50 SG (2.8 oz) 9C

II -12.1 Sivanto (14 fl oz) 4D Sivanto (14 fl oz) 4D Vacuum

III 0.0 B. bassiana+pyrethrum 3A (1qrt) Vacuum Rimon 0.83 EC (12 fl oz) 15 +

Brigade (16 oz) 3A

IV 7.8 Rimon 0.83 EC (12 fl oz) 15 + Brigade (16 oz) 3A

Met52 EC(16 fl oz) + Debug Turbo (104 fl oz)

Met52 EC (16 fl oz) + AzaGuard (16 fl oz)

V 8.0 Assail 70 WP (3 oz) 4A* Assail 70 WP (3 oz) 4A Assail 70 WP (3 oz) 4A

VI 11.5 Vacuum Vacuum Vacuum

VII 27.3 Vacuum Sivanto (14 fl oz) 4D + Debug Turbo (104 fl oz)

Rimon 0.83 EC (12 fl oz) 15 + Brigade (16 oz) 3A

VIII 32.7 Pfr-97 (2 lb) + Neemix (9 fl oz)

Pfr-97 (2 lb) + Neemix (9 fl oz)

Vacuum

IX 46.8 B. bassiana+pyrethrum 3A (1qrt) B. bassiana+neem (1qrt) Beleaf 50 SG (2.8 oz) 9C

X 70.8 Sequoia (4.5 oz) 4C Sequoia (4.5 oz) 4C Vacuum

XI 78.3 Untreated Untreated Untreated

XII 85.7 B. bassiana+neem (1qrt) B. bassiana+pyrethrum 3A +neem (1qrt)

B. bassiana+pyrethrum 3A (1qrt)

*Mode of action group

Product efficacy against lygus nymphs

-40

-29

-10 -9 -2

3 4 11 12 15

21 25

42

79

-60

-40

-20

0

20

40

60

80

% C

hang

e in

inse

ct n

umbe

rs

Product efficacy against lygus adults

-24

0

19 33

62 71 74

91

130 133 133 147

159 163

-50

0

50

100

150

200

% C

hang

e in

inse

ct n

umbe

rs

Product efficacy against all life stages

-37

-19 -8

-3

3 11 13

20 22 24 24 32

49

65

-60

-40

-20

0

20

40

60

80

% C

hang

e in

inse

ct n

umbe

rs

Conclusions

• Lygus infestations were very high and only two treatments reduced their populations and one treatment prevented their buildup

• Consider IPM strategy by using chemical, botanical, microbial, and mechanical tools

Acknowledgements Grower and Team Dave Murray, Sundance Berry Farms Ted Ponce Industry Partners Agro Logistics Systems, Arysta LifeScience, Bayer CropScience, BioSafe Systems, Certis USA, Dow AgroSciences, Helena Chemicals, Laverlam International Corp., and Monsanto BioAg Technical assistance Sundance Berry Farms field crew Chris Martinez Fritz Light Kristin Nicole Stegeman Tamas Zold

Thank you!

Full articles of these studies can be found at http://ucanr.edu/strawberries-vegetables