2017 Sustainable Ag Expo

2017 SUSTAINABLE AG BestEXPO Management Practices for the Monitoring and Control of Mealybug Vectors of Grape Leafroll Virus

Brian Hogg, Kai Blaisdell, Valeria Hochman- Adler, Monica Cooper, Deborah Golino, Rodrigo Almeida, and Kent Daane

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Grape vine leafroll associate virus: We will discuss insecticides for control of the ‘epidemic’ leafroll scenario that growers were initially worried about.

photo courtesyNovember of Deborah 13-15, 2017Golino | San Luis Obispo, CA www.sustainableagexpo.org Vectors of Viral Pathogens in Vineyards

1. GLRaV Factors that Impact Control a) mealybug and leafroll species b) facts about mealybug-leafroll epidemiology 2. Vector (Mealybug) Controls a) insecticides for mealybug: which are best b) pheromones for monitoring and control c) biological controls 3. Areawide Control Programs? a) monitoring b) insecticide resistance c) mating disruption in Napa

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Vectors of Viral Pathogens in Vineyards

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org GLRaV Insect Vectors •>700 plant viruses •ca. 70% have insect, mite, nematode or fungal vectors whiteflies

aphids

soft scales November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org GLRaV Insect Vectors •>700 plant viruses •ca. 70% have insect, mite, nematode or fungal vectors whiteflies •most GLRaVs are closterovirids… and most closterovirids are aphids vectored by whiteflies, aphids, soft scales and mealybugs

soft scales November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org GLRaV-3 Mealybug Vectors in California Grape mealybug Obscure mealybug Longtailed mealybug The native grape mealybug (Pseudococcus maritimus) is the prevalent species and the likely historical vector of GLRaV in USA

Vine mealybug Citrus mealybug Gill’s mealybug The invasive vine mealybug (Planococcus ficus) is in California and represents the more important vector

Rosciglione and Gugerli, 1987, Engelbrecht and Kasdorf 1990, Golino et al. 2002, Charles et al. 2006, Tsai et al. 2011

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Key Transmission Facts – Acquisition •Crawlers acquired virus w/in 1 hr •Peak at 24 hr

Tsai, Almeida et al. Phytopath. (2008)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Key Transmission Facts – Inoculation •Crawlers inoculated virus w/in 1 hr •Peak at 24 hr

Tsai, Almeida et al. Phytopath. (2008)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Which leafroll species (or strain) do you have?

Sharma et al. PLos One. 2011

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Eight GLRaV-3 strains found (to date) in Napa vineyards, with multiple stains in some vineyards.

f GLRaV-3a e GLRaV-3b d a GLRaV-3c GLRaV-3d GLRaV-3e GLRaV-3f GLRaV-3ab GLRaV-3ac c GLRaV-3ad b GLRaV-3bc GLRaV-3bd GLRaV-3cd GLRaV-3abc Sharma et al. PLos One. 2011

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Vectors of Viral Pathogens in Vineyards

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org In 1952-53, in a Tulare Co. table grape vineyard with a history of grape mealybug infestation, excellent control (<1%) was achieved with low rates of parathion

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Parathion Dinoseb Permethrin Chloroyrifos Methidathion

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Obscure mealybug Vine MB causes more damage (South America) 1) more eggs, more generations 2) feeds on leaves 3) more honeydew excretion

Long-tailed mealybug (Australia) Vine mealybug (Mediterranean)

Grape mealybug (native)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org 0 1 2 3

100 Rating system for fruit damage 80 “3” Severe damage / lost cluster 60 “2” Partial damage 40 “1” Minor damage

20 “0” No damage Damage Damage (% catagory) 0

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org In the 1990s, Chemical Industry and UC sought alternates to in-season OPs and Carbamates 40 a

b b b a 30

100 ) 20 80 b category b 10 b

60 (% (%

40 0 Applaud Control damage (buprofezin) 20 Admire Lorsban

Fruit (Imidacloprid) (chlorpyrifos) 0 Applaud Control

Admire Lorsban Spray Volume: 100 GPA; Air-blast Sprayer; label rate. (as a delayed- Details in Daane et al. 2006. Calif. Agricul. 60(1): 31-38. dormant) Vine mealybug (P. ficus) was the target pest; Del Rey, CA.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Since the 1990s, more effective materials have been added to the tool box

c 30

10 b b

Fruit damage (% category) (% damage Fruit 5 a a 0 Spirotetramet Buprofezin Control (Movento) (Applaud) Clothianidin Acetamiprid (Belay) (Assail)

Spray Volume: 100 GPA; Air-blast Sprayer; label rate (Applaud 12 oz per ac) Belay & Movento on 21 June 2011, Applaud & Assail on 7 July 2011 Planococcus ficus, Lodi-Woodbridge wine grapes, Lodi, CA

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Understanding the systematic uptake of pesticide

Foliar spray Spirotetramat (SPTA)

Spirotetramat metabolite (SPTA Enol)

Modified after: http://www.uic.edu/classes/bios/bios100/lectf03am/translocation.jpg

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Spirotetramat

Enol

Enol-Glc

Ketohydroxy

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Spirotetramat

Enol

Enol-Glc

Ketohydroxy

Spirotetramat is a tetronic acid derivative and acts as a lipid biosynthesis inhibitor. Lipids (fats, oils, waxes, vitamins, hormones) are essential to an animal’s existence. Spirotetramat is effective against juvenile stages (like a growth hormone), but can reduce adult fecundity and fertility. Death also occurs because mealybugs will have their energy transport system disrupted and should cease movement.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org A C

6.14 2.41

DAD1 A, Sig=250,4 Ref=off (MOVENTO_SC 2015-08-24 08-50-47\065-0501.D) mAU

8.536

50 B D 40

3.620

6.140

4.350

4.200 20 6.14

5.410

4.976

5.585 10

7.077

4 5 6 7 8 9 10 min

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org 1000 Example of some of the results

100 Spirotetramat Enol 10

0.1

0.01

Mean ppm of compound sample per of compound ppm Mean 0.001

0.0001 0.2 4 37 110 184 212 320 (5 hr) Days after treatment

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Questions we have been trying to address:

• Timing & methods of application • Location & age of pest population • Vine physiology • Conversion of SPAT to SPAT-Enol? • Movement of SPAT & SPAT-Enol

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Development of mating disruption – led by pheromone chemist Jocelyn Millar, who has identified mealybug sex pheromones (Walt Bentley)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Identified and synthesized sex pheromone

Female emits sex pheromone

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Pheromone trap captures showing GMB in Washington 400

300 2010

2011 SE) / trap / week / / trap SE)

± 200

100 Malemealybugs ( 0 Apr May Jun Jul Aug Sept Oct Nov Dec

Bahder, Rayapati, Daane, Millar & Walsh. 2013. Journal of Economic Entomology.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Mating disruption - synthesized sex pheromone

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Small-plot studies with sprayable formulation Period: 2003 and 2004*

Crop Destruct: Small plots (0.2-0.3 ha) in raisin vineyards

2004 Design: Applied sprayable

microencapsulated pheromone (10 g Kuenen. Kuenen. 2006.

- / ha) every 3 wks (20 Apr to 18 Jul);

90. -

Malakar split-plot, 5 reps 99:1280 Insecticides: Buprofezin on all plots (in 2003 plots also received chlorpyrifos)

Measured: Male VMB flight, Journal Entomology Journal Economic of Walton, Walton, Daane, Larsen Millar, Bentley, & mealybug density via timed-counts, rated crop damage.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Small-plot studies with sprayable formulation

100 A

80 Control Mating disruption

20 Kuenen. Kuenen. 2006. - 0

Male mealybugs per trap per week

90.

- Malakar

20 99:1280 B 15

VMB / vine / 2 min count

Walton, Walton, Daane, Larsen Millar, Bentley, & Entomology Journal Economic of 0 Apr 1 May 1 Jun 1 Jul 1 Aug 1 Sept 1 Oct 1 Nov 1 Dec 1

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Small-plot studies with sprayable formulation

8.8% loss 2.8% loss 100 0 1 80

Kuenen. Kuenen. 2006.

90. -

Malakar 20 Fruit damage Fruit (%) by category

99:1280 2 3 0 Control Pheromone Methodology (0 – 3 scale) Unmarketable cluster (3) Mealybug damage (2)

Honeydew, few VMB (1) Journal Entomology Journal Economic of Walton, Walton, Daane, Larsen Millar, Bentley, & No damage (0)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Small-plot studies with sprayable formulation

250

*** 200 Control Mating disruption

150 ***

100

** ** Male mealybugs / trap / mealybugs Male 50 NS NS ***

0 0 7 14 21 28 35 42 49 Residual activity (in days)

Walton, Daane, Bentley, Millar, Larsen & Malakar-Kuenen. 2006. Journal of Economic Entomology 99: 1280-90.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org 12 Control 10 Early & Mid-Season MD Full Season MD 8

2 VMB VMB malesweek pertrap per

Mar Apr May Jun Jul Aug Sept

Daane et al. unplublished, 2017 study

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Large-plot studies with plastic dispensers Period: 2005 to 2008

Experimental permit for use: Large plots (5-20 ha) in raisin and wine vineyards

Typically Design: Deployed plastic dispensers (100-150 mg a.i. / dispenser, one application per season, ca. 500 / ha), split-plot, 4-6 reps per region

Insecticides: Variable

Measured: Male VMB flight, mealybug density via timed-counts, rated crop damage. Daane et al. unplublished

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Mating Disruption May Improve Bio-Control 25 500-1000 A. Damage pseudococci ratings 300-500 C. 3 20 peregrinus a parasitoids/acre 2 b 1 15 b

Fruit damage by category (%) category by Fruit damage 5

0 BioControl MD & Conventional Daane et al., unpublished data (Applaud) Biocontrol (Lorsban, Admire, Napa. 2008 (Applaud) Applaud)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Large-plot studies with plastic dispensers: CONS

50 Mating disruption (BioControl & Applaud) Conventional 40 (Lorsban, Admire, 2X Applaud)

1 20 2

10 VMB / vine / min count 3 3 0 4 Apr May Jun Jul Aug

Daane et al. unplublished

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Large-plot studies with plastic dispensers: CONS

50 Mating disruption (BioControl & Applaud) Conventional 40 (Lorsban, Admire, 2X Applaud)

10 VMB / vine / min count 3

0 Apr May Jun Jul Aug

Daane et al. unplublished

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Large-plot studies with plastic dispensers: CONS

100 a Mating disruption 80 50 ab (BioControl & Applaud) Conventional 60 40 (Lorsban, Admire, 2X Applaud) 40 b 30

20 Percent reduction of VMB of reduction Percent 0 20 Low Medium High

10 VMB / vine / min count 3

0 Apr May Jun Jul Aug

Daane et al. unplublished

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Could “puffers” reduce costs? (Welter & Kurtural) Lower labor costs & better release control….

Puffers for pheromone release may reduce costs further, requiring only placement of 4 puffers / ha, and automating pheromone release to time of day

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Could “meso” dispensers reduce costs? Lower labor costs .. but fewer ‘point’ sources ‘meso dispensers’ may reduce costs, requires placement of 50 / ha, but they did not perform as well

3.0 Damage categories b 2.5 3-Unmarketable 2-Some damage 1-Little damage 2.0 0-No damage

1.5 b

1.0

0.5 Fruit damage category by damage Fruit (%) a 0.0 Conventional Standard MD Meso MD

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org California parasites of “Grape MB” complex

Acerophagus angelicus Grape mealybug parasitoids • found in all regions • provide effective control • disrupted by cultural practices insecticides high vine vigor

Acerophagus notativentris Tetracnemoidea sydneyensis

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org What controls are available for organic?

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Anagyrus pseudococci – female “Israel” – similar California, S. Italy “N. Italy” – released 2006-08 “E. Spain” – imported 2008

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Problem I: mealybug location

100 Exposed Mealybug Hidden Mealybug 80

Daane et al. unplublished

20 Parasitized mealybugs (%) mealybugs Parasitized

May 1 Jun 1 Jul 1 Aug 1 Sept 1 Oct 1 Nov 1

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Problem II. Parasite Overwintering Biology

Outdoors (ambient air temperature) 15 Mar ` Indoors (insectary)

28 Feb

23 Jan

19 Dec

15 Nov Oviposition date Oviposition

18 Oct

Oct ‘01 Nov Dec Jan ‘02 Feb Mar Apr May Jun A. pseudococci oviposition and adult emergence dates

Daane, Malakar-Kuenen, Walton et al. 2005. Biol. Control

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Ant / homopteran mutualism – both animals benefit

Daane et al. 2007 Ecol. Entomol Nelson et al. 2007. Envion. Entomol, Daane et al. 2008. J Econ Entomol Cooper et al. 2008 Calif Agricul

 Alex Wild

AlexWild 

photo credit: Charles Chien

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Vectors of Viral Pathogens in Vineyards

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Dispersal Mechanisms Were Poorly Known 1 2

photo from web - unknown 3 4

Courtesy Lucia Varela

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Keeping the mealybug out of the vineyard and using effective insecticides when needed remains the best controls. UC personnel worked farmers, industry and PCAs to develop better insecticide programs.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Can we simply kill all mealybugs for GLRaV control?

In a newly planted block, two treatments: insecticides vs control Cabernet Sauvignon (2008)

Grape MB & Grape MB & GLRaV-3 Red Blotch (?)

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Insecticide GLRaV weak source block

120 Control 119 120 118 119 117 118 116 117 115 116 114 115 113 114 112 113 111 112 110 111 109 110 108 109 107 108 106 107 105 106 104 105 103 104 102 103 101 102 100 101 99 100 98 99 97 98 96 97 95 96 94 95 93 94 92 93 91 92 90 91 89 90 88 89 87 88 86 87 85 86 84 85 83 84 82 83 81 82 80 81 79 80 78 79 77 78 76 77 75 76 74 75 73 74 73 Highway29 72 72 71 71 70 70 69 69 68 68 67 67 66 66 65 65 64 64 63 63 62 62 61 61 60 60 59 59 58 58 57 57 56 56 55 55 54 54 Two annual 53 53 52 52 51 51 50 50 49 49 48 48 47 47 46 46 45 45 44 44 43 43 42 42 applications of a 41 40 41 39 40 38 39 GLRaV moderate block source moderate GLRaV 38 37 37 36 36 35 35 34 34 33 33 32 32 31 31 30 30 combination of 29 29 28 28 27 27 26 26 25 25 24 24 23 23 22 22 21 21 20 20 19 19 18 18 either Applaud, 17 17 16 16 15 15 14 14 13 13 12 12 11 11 10 10 9 9 8 8 7 7 6 6 Admire, Clutch or 5 5 4 4 3 3 2 2 row “1” missing1 1 Movento GLRaV strong source block

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Where did the GLRaV-infected vines appear?

2011 Insecticides 2009 No insecticides 2011

GLRaV3b 2011 2013 2011

2012 2011

2011 GLRaV3a 2010 GLRaV3c 2012 GLRaV3d

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Insect growth regulator Applaud (Buprofezin) c 30 Novel materials Neonicotenoids 25 Admire (Imidacloprid) Insect must feed Clutch (Clothianidin) 20 Slower kill (1-7 days) Relatively low residual Assail (Acetamiprid) 15

Biosynthesis inhibitor 10 b b Movento (Spirotetramet) 5 a a OPs and Carbamates 0 Lorsban (Chlorpyrifos)* Spirotetramet Buprofezin Control Lannate (Methomyl)* (Movento) (Applaud) Dimethoate* Clothianidin Acetamiprid (Clutch) (Assail) *Listing here materials still effective and still registered (leafhoppers) Spray Volume: 100 GPA; Air-blast Sprayer; label rate (Applaud 12 oz per ac) Clutch & Movento on 21 June 2011, Applaud & Assail on 7 July 2011 Planococcus ficus, Lodi-Woodbridge wine grapes, Lodi, CA

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Areawide control trial in Napa (2011-2012)

For Grape Leafroll Associated Viruses - we know the vectors - - we know their transmission efficiency - we know the effectiveness of controls 69 ha

69 ha

61 ha

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org An areawide program was tested: 1) monitoring the vector, 2) VMB mating disruption and applying insecticides as needed, and 3) roguing diseased vines ♂VMB per trap: 0 21-50 1-10 51-100 11-20 >100

2011 2012

Results for 1 of 3 sites, shows that further spread can be prevented, and that farmers must work together.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Comparison of traps in hotspots between years

300 Numbers of vine MB in Increase traps with total >20 VMB 250 Decrease in either year generally No change decreased between 2011 200 and 2012, except in two trap / males cases. ficus 150

When proper treatments Pl. are not applied the population will increase 100 and spread.

50 Total number Total

0 2011 2012

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Insecticides for ‘high density’ Mating disruption to prevent spread

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org 100% infection

2011 2009

GLD vines GLD 2011 2011 Time 2011 2011 2011 2010

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org What about areawide control with In clean block insecticides? remove the infected vines

Treat new blocks to kill dispersing crawlers Treat source blocks to lower populations

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org If source blocks can Continue to eventually remove infected vines and treat for be pulled… dispersing crawlers

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org Conclusions & Questions 1) Different mealybug species in California vineyards. 2) Sampling using visual counts is tedious (pheromone traps). 3) Chemical controls remain the most common tool: Movento, Belay, Admire (and generic), Assail, Platinum, Venom, Applaud, Sivanto (flupyradifurone), Sequoia (sulfoxaflor, check registration). 4) Mating disruption for vine mealybug to maintain low densities – a lot more potential with the sprayable formulation. 5) There are excellent bio-controls for grape MB, and partial biocontrol for vine MB; ants have a negative impact on bio-controls and a mating disruption and selective insecticides has a positive interaction with mating disruption 6) Mealybugs vector GLDs and this changes control decisions – start thinking about areawide control as the best program.

November 13-15, 2017 | San Luis Obispo, CA www.sustainableagexpo.org