2017 SUSTAINABLE AG EXPO

Transcription

1 2017 SUSTAINABLE AG EXPO Best 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

2 Grape vine leafroll associate virus: We will discuss insecticides for control of the epidemic leafroll scenario that growers were initially worried about. photo courtesy November of Deborah 13-15, 2017 Golino San Luis Obispo, CA

3 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

4 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

5 GLRaV Insect Vectors >700 plant viruses ca. 70% have insect, mite, nematode or fungal vectors whiteflies aphids soft scales

6 GLRaV Insect Vectors >700 plant viruses ca. 70% have insect, mite, nematode or fungal vectors most GLRaVs are closterovirids and most closterovirids are vectored by whiteflies, aphids, soft scales and mealybugs aphids whiteflies soft scales

7 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

8 Key Transmission Facts Acquisition Crawlers acquired virus w/in 1 hr Peak at 24 hr Tsai, Almeida et al. Phytopath. (2008)

9 Key Transmission Facts Inoculation Crawlers inoculated virus w/in 1 hr Peak at 24 hr Tsai, Almeida et al. Phytopath. (2008)

10 Which leafroll species (or strain) do you have? Sharma et al. PLos One. 2011

11 Eight GLRaV-3 strains found (to date) in Napa vineyards, with multiple stains in some vineyards. e f d c a b GLRaV-3a GLRaV-3b GLRaV-3c GLRaV-3d GLRaV-3e GLRaV-3f GLRaV-3ab GLRaV-3ac GLRaV-3ad GLRaV-3bc GLRaV-3bd GLRaV-3cd GLRaV-3abc Sharma et al. PLos One. 2011

12 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

13 In , in a Tulare Co. table grape vineyard with a history of grape mealybug infestation, excellent control (<1%) was achieved with low rates of parathion

14 Parathion Dinoseb Permethrin Chloroyrifos Methidathion

15 Vine MB causes more damage 1) more eggs, more generations 2) feeds on leaves 3) more honeydew excretion Vine mealybug (Mediterranean) Obscure mealybug (South America) Long-tailed mealybug (Australia) Grape mealybug (native)

16 Damage (% catagory) Rating system for fruit damage 3 Severe damage / lost cluster 2 Partial damage 1 Minor damage 0 No damage

17 Fruit damage (% category) In the 1990s, Chemical Industry and UC sought alternates to in-season OPs and Carbamates 40 a 100 b b b a b b b Applaud Control Admire Lorsban (as a delayeddormant) 0 Admire (Imidacloprid) Applaud (buprofezin) Lorsban (chlorpyrifos) Control Spray Volume: 100 GPA; Air-blast Sprayer; label rate. Details in Daane et al Calif. Agricul. 60(1): Vine mealybug (P. ficus) was the target pest; Del Rey, CA.

18 Fruit damage (% category) Since the 1990s, more effective materials have been added to the tool box 30 c b b 5 0 a Spirotetramet (Movento) Clothianidin (Belay) a Buprofezin (Applaud) Acetamiprid (Assail) Control 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

19 Understanding the systematic uptake of pesticide Foliar spray Spirotetramat (SPTA) Spirotetramat metabolite (SPTA Enol) Modified after:

20 Spirotetramat Enol Enol-Glc Ketohydroxy

21 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.

22 A C mau DAD1 A, Sig=250,4 Ref=off (MOVENTO_SC \ D) B D min

23 Mean ppm of compound per sample Example of some of the results Spirotetramat Enol (5 hr) Days after treatment

24 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

25 Development of mating disruption led by pheromone chemist Jocelyn Millar, who has identified mealybug sex pheromones (Walt Bentley)

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27 Identified and synthesized sex pheromone Female emits sex pheromone

28 Male mealybugs (±SE) / trap / week 400 Pheromone trap captures showing GMB in Washington Apr May Jun Jul Aug Sept Oct Nov Dec Bahder, Rayapati, Daane, Millar & Walsh Journal of Economic Entomology.

29 Mating disruption - synthesized sex pheromone

30 Walton, Daane, Bentley, Millar, Larsen & Malakar-Kuenen Journal of Economic Entomology 99: Small-plot studies with sprayable formulation Period: 2003 and 2004* Crop Destruct: Small plots ( ha) in raisin vineyards 2004 Design: Applied sprayable microencapsulated pheromone (10 g / ha) every 3 wks (20 Apr to 18 Jul); split-plot, 5 reps Insecticides: Buprofezin on all plots (in 2003 plots also received chlorpyrifos) Measured: Male VMB flight, mealybug density via timed-counts, rated crop damage.

31 VMB / vine / 2 min count Male mealybugs per trap per week Walton, Daane, Bentley, Millar, Larsen & Malakar-Kuenen Journal of Economic Entomology 99: Small-plot studies with sprayable formulation Control Mating disruption A B 0 Apr 1 May 1 Jun 1 Jul 1 Aug 1 Sept 1 Oct 1 Nov 1 Dec 1

32 Walton, Daane, Bentley, Millar, Larsen & Malakar-Kuenen Journal of Economic Entomology 99: Fruit damage by category (%) Small-plot studies with sprayable formulation % loss 2.8% loss Control Pheromone Methodology (0 3 scale) Unmarketable cluster (3) Mealybug damage (2) Honeydew, few VMB (1) No damage (0)

33 Male mealybugs / trap Small-plot studies with sprayable formulation *** *** Control Mating disruption 100 ** ** 50 *** NS NS Residual activity (in days) Walton, Daane, Bentley, Millar, Larsen & Malakar-Kuenen Journal of Economic Entomology 99:

34 VMB males per trap per week Control Early & Mid-Season MD Full Season MD Mar Apr May Jun Jul Aug Sept Daane et al. unplublished, 2017 study

35 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 ( mg a.i. / dispenser, one application per season, ca. 500 / ha), split-plot, 4-6 reps per region Insecticides: Variable Daane et al. unplublished Measured: Male VMB flight, mealybug density via timed-counts, rated crop damage.

36 Fruit damage by category (%) Mating Disruption May Improve Bio-Control A. pseudococci C. peregrinus parasitoids/acre Damage ratings a 3 2 b 1 b Daane et al., unpublished data Napa BioControl (Applaud) MD & Biocontrol (Applaud) Conventional (Lorsban, Admire, Applaud)

37 VMB / vine / 3 min count Large-plot studies with plastic dispensers: CONS Mating disruption (BioControl & Applaud) Conventional (Lorsban, Admire, 2X Applaud) Apr May Jun Jul Aug Daane et al. unplublished

38 VMB / vine / 3 min count Large-plot studies with plastic dispensers: CONS Mating disruption (BioControl & Applaud) Conventional (Lorsban, Admire, 2X Applaud) Apr May Jun Jul Aug Daane et al. unplublished

39 Percent reduction of VMB VMB / vine / 3 min count Large-plot studies with plastic dispensers: CONS a ab b Mating disruption (BioControl & Applaud) Conventional (Lorsban, Admire, 2X Applaud) 0 Low Medium High Apr May Jun Jul Aug Daane et al. unplublished

40 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

41 Fruit damage by category (%) 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 Damage categories 3-Unmarketable 2-Some damage 1-Little damage 0-No damage b b a Conventional Standard MD Meso MD

42 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

43 What controls are available for organic?

44 Anagyrus pseudococci female Israel similar California, S. Italy N. Italy released E. Spain imported 2008

45 Parasitized mealybugs (%) Problem I: mealybug location Exposed Mealybug Hidden Mealybug Daane et al. unplublished 20 0 May 1 Jun 1 Jul 1 Aug 1 Sept 1 Oct 1 Nov 1

46 Oviposition date Problem II. Parasite Overwintering Biology 15 Mar ` Outdoors (ambient air temperature) Indoors (insectary) 28 Feb 23 Jan 19 Dec 15 Nov 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 Biol. Control

47 Alex Wild Ant / homopteran mutualism both animals benefit Daane et al Ecol. Entomol Nelson et al Envion. Entomol, Daane et al J Econ Entomol Cooper et al Calif Agricul Alex Wild photo credit: Charles Chien

48 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

49 Dispersal Mechanisms Were Poorly Known 1 2 photo from web - unknown 3 4 Courtesy Lucia Varela

50 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.

51 Can we simply kill all mealybugs for GLRaV control? In a newly planted block, two treatments: insecticides vs control Cabernet Sauvignon (2008) Grape MB & GLRaV-3 Grape MB & Red Blotch (?)

52 GLRaV moderate source block Insecticide GLRaV weak source block Control row 1 missing GLRaV strong source block Highway 29 Two annual applications of a combination of either Applaud, Admire, Clutch or Movento

53 Where did the GLRaV-infected vines appear? Insecticides No insecticides GLRaV3b GLRaV3a GLRaV3c GLRaV3d

54 Insect growth regulator Applaud (Buprofezin) Neonicotenoids Admire (Imidacloprid) Clutch (Clothianidin) Assail (Acetamiprid) Novel materials Insect must feed Slower kill (1-7 days) Relatively low residual c Biosynthesis inhibitor Movento (Spirotetramet) OPs and Carbamates Lorsban (Chlorpyrifos)* Lannate (Methomyl)* Dimethoate* *Listing here materials still effective and still registered (leafhoppers) 10 5 a 0 Spirotetramet (Movento) a Clothianidin (Clutch) b Buprofezin (Applaud) b Acetamiprid (Assail) Control 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

55 Areawide control trial in Napa ( ) 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

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

57 Total number Pl. ficus males / trap Comparison of traps in hotspots between years 300 Numbers of vine MB in traps with total >20 VMB in either year generally decreased between 2011 and 2012, except in two cases. When proper treatments are not applied the population will increase and spread Increase Decrease No change

58 Insecticides for high density Mating disruption to prevent spread

59 GLD vines 100% infection Time

60 What about areawide control with insecticides? In clean block remove the infected vines Treat new blocks to kill dispersing crawlers Treat source blocks to lower populations

61 If source blocks can eventually be pulled Continue to remove infected vines and treat for dispersing crawlers

62 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.