Optimizing the use of the codling moth granulovirus: Final Report L. Lacey S. Arthurs R. Fritts R. Behle A. Knight

Optimizing the use of the codling moth granulovirus: Final Report

L. LaceyL. LaceyS. ArthursS. ArthursR. FrittsR. FrittsR. BehleR. BehleA. KnightA. Knight

OBJECTIVES:

1. Determine the lowest dosage of CpGV that will provide effective control of codling moth larvae.2. Determine optimal intervals for spray

application.3. Continue to assess the shelf life of commercial formulations at various temperatures.4. Investigate the potential of several adjuvants for protecting CpGV from solar

degradation.

Significant findings:Significant findings:

● Season-long treatments of CpGV (Cyd-X) at 3 rates (1, 3 and 6 oz acre) and 3 application intervals (7, 10 and 14 days) resulted in significantly fewer deep entries and surviving larvae but did not reduce the proportion of fruit damaged by codling moth. ● There was a significant trend of fewer deep entries and higher larval mortality rates with increasing rate of CpGV and shorter application interval.● In replicated ½ acre plots, CpGV provided > 90% larval mortality at 1, 2 and 3 oz/acre, but was not as effective as Guthion in protecting fruit.● Bioassay procedures to screen adjuvants providing possible UV protection of CpGV formulations were developed.

Significant findings Significant findings continued:continued:

The efficacy of 3 commercial CpGV formulations were significantly reduced (52-77%) by exposure to UV light (9.36 × 106 joules/m2) in a solar simulator.

Although lignin encapsulation provided significant protection of CpGV exposed to simulated sunlight in laboratory studies, under field conditions it did not.

The Cyd-X and Virosoft formulations of CpGV maintained larvicidal activity after storage at 2 and 25˚C for over 132 weeks, but activity was sharply reduced after storage at 35º for 16 and 40 weeks, respectively.

Applying CpGV in the orchardApplying CpGV in the orchard

Experimental orchard

Trees treated individually in a randomized plot design

Commercial orchard

Blocks sprayed using operational equipment

Field evaluations of CpGVField evaluations of CpGV

Experimentally assess efficacy of weekly Experimentally assess efficacy of weekly applications of Cyd-X at 1, 2, 3 oz/acapplications of Cyd-X at 1, 2, 3 oz/ac

Determine optimal spray interval and Determine optimal spray interval and dosage of Cyd-X applied every 7, 10 or dosage of Cyd-X applied every 7, 10 or 14 days at 1, 3, or 6 oz/ac14 days at 1, 3, or 6 oz/ac

% and degree of fruit damage, larval % and degree of fruit damage, larval mortality, sampling overwintering larvaemortality, sampling overwintering larvae

F 9,99 = 0.99; P = 0.454

0

10

20

30

40

50

60

1oz 3oz 6oz Control

% C

M f

ruit

inju

ry

F 9,49 = 0.99; P < 0.0001

a

dd

bccdcd

bc bcb

bc

0

0.2

0.4

0.6

0.8

1

1oz 3oz 6oz Control

Pro

port

ion

of d

eep

entr

ies

F 9,99 = 48.5; P < 0.0001ab

cd

f

de cd bc

ebc bc

20

40

60

80

100

1oz 3oz 6oz Control

% L

arva

l mor

talit

y 7d

10d

14d

Fruit damage, deep entries and CM mortality following different treatments of Cyd-X in individual tree plots.

Grower applicationsGrower applications

Assessment of:Assessment of:

Fruit damageFruit damage

larval mortalitylarval mortality

adult adult populationspopulations

overwintering overwintering larvaelarvae

F 3,17 = 54.5; P < 0.001

c

abb

20

40

60

80

100

1oz 2oz 3oz Untreated

% L

arv

al m

ort

alit

yF 4,22 =4.5; P = 0.01

abab

bc

a

c

0

2

4

6

8

10

12

1oz 2oz 3oz Untreated Guthion

% C

M fr

uit i

njur

y

F 4,22 = 7.6; P < 0.001

bc

a

c

b

c

0

4

8

12

16

1oz 2oz 3oz Untreated Guthion

Inte

rcep

tion

trap

(bi

-wee

kly

catc

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Fruit damage, CM mortality and interception trap catches following different treatments of Cyd-X in ½ acre blocks in a 21 acre commercial orchard (data for 1st generation).

CpGV and MD is effectiveCpGV and MD is effective

Year #Applications/season

% CM fruit injury/1000 fruit

Moths/pheromone trap

1st gen. 2nd gen. 1st flight

2nd flight

2003 14 1.27* 0.84* 27.1 5.3

2004 8 0.13 0.21 6.2 5

2005 12 0.17 0.1 13.5 101CpGV (Cyd-X) applied at 2 or 3 fl.oz/A and 100 gal./ A, * assuming 300 fruit/tree

Fruit injury and codling moth populations in 3A organic Golden Delicious treated with CpGV and MD (Parker Heights, WA)

a

Most people are familiar with the CM virus. It has been working relatively well. Example of organic orchard we have been following for 3 years where the grower has relied on CpGV and MD. The orchardist considered oil applications detrimental for tree health. In the first season monitoring trap catches fell by >80% after the first generation. Populations were reduced in 2004 and 2005, especially in the second flight. Fruit damage has been maintained at < 1% without additional interventions.But the major problem is that the virus granules, are relatively quickly deactivated by sunlight, especially in the ultraviolet range. This means frequent reapplication is needed, (see table). The slow speed of kill is also an issue, resulting in the occurrence of shallow stings in fruit.

Laboratory studiesLaboratory studies

Quantitative bioassaysQuantitative bioassays Shelf life at 36, 77, and 95˚FShelf life at 36, 77, and 95˚F UV sensitivityUV sensitivity

Weeks in storage after which less than 95% mortality of codling moth larvae occurs (100,000 fold dilution)

36˚F - 2˚C 77˚F - 25˚C 95˚F - 35˚C

Carpovirusine 116 2-4 2

Virosoft 132+ 132+ 40

Cyd-X 140+ 140+ 16

+ end point not yet determined

Solar simulator and half apple system used to

bioassay CpGV formulations

Apples were sprayed with CpGV suspensions in a DeVries spray cabinet

Evaluation of formulation components as Evaluation of formulation components as ultraviolet light protectantsultraviolet light protectants

a

The procedure basically involved spraying apples with this track sprayer with a controlled dosage of virus and then irradiating them in this Atlas solar simulator. Larvae were then infested to bioassay residual activity.

Mean CM mortality on apples treated with standard rate of CpGV (1000-fold dilution) and exposed to 9.36 × 106 joules/m2 simulated sunlight plus controls.

Virosoft Carpovirusine Cyd-X

UV 29.7 20.4 46.8No UV 95.1 90.2 98. 2% red. 68.8 77.4 52.3

Evaluation of spray-dried lignin-based Evaluation of spray-dried lignin-based formulations as ultraviolet light formulations as ultraviolet light protectantsprotectants

a

So now I will describe a second batch of studies where we looked at virus formulations. This was work with Bob Behle at IL who has been working with these formulations with NPVs of cabbage looper and also Bt. Spray drying is the most widely used industrial process involving particle formation and drying. It is suited for the production of dry solids in either powder, granulate or agglomerate form from liquid feedstocks. Spray drying involved the atomization of the liquid feedstock into a spray of droplets and contacting the droplets with hot air in a drying chamber. The sprays are produced with either rotary (wheel) or nozzle atomizers. Evaporation of water from the droplets and formation of dry particles processed under controlled temperature and airflow conditions. Powder is discharged continuously from the drying chamber.

Evaluation of spray-dried lignin-based formulations as ultraviolet Evaluation of spray-dried lignin-based formulations as ultraviolet light protectantslight protectants

Percentage neonate mortality on irradiated fruit with three rates of virus

Formulation

High dose (3 × 1010 OB/L)

Med. dose (3 × 109 OB/L)

Low dose (3 × 108 OB/L)

Untreated 21.4c 21.4b 21.4

Cyd-X 55.7b 44.5a 37.8

Virus/Lignin 95.4a 41.7a 37.3Data show average for five replicate tests (n = 25)Letters show Fisher’s LSD at P < 0.05

a

This shows further tests with the lignin formulation. Same thing again but at 3 doses. We also checked and found the blank carrier did not have any significant effect.

Evaluation of spray-dried lignin-based formulations as ultraviolet Evaluation of spray-dried lignin-based formulations as ultraviolet light protectantslight protectants

Formulation First generation1 Second generation2

% fruit damage

% mortality

% fruit damage

% mortality

Untreated 6.1 38.5b 33.8 27.4c

Blank Lignin 6.3 36.3b 32.1 17.8c

Cyd-X 11.1 93.2a 26.2 64.6ab

Virus/Lignin 9.1 87.8a 27.9 71.4a

Cyd-X (½ rate) - - 28.5 65.7ab

Virus/Lignin (½ rate)

- - 23.2 58.6b1Four applications at 6.57 × 1012 granules/ha2Three applications, ½ trees sprayed at a reduced rate (2.2 × 1012 granules/ha)

Field tests (Golden Delicious), 14 d spray interval, n=10 trees

a

We also ran field tests in the Golden block. We used a 14 day spray interval. Lignin did not work in either generation. In the first generation we did not observed an effect, but mortality in virus controls was also very high. We noticed dose was again more significant with the lignin formulation. In the second generation we reduced the rate in ½ the trees. We found a marginal effect at high doses, but again (as in lab tests) did not work at the low dose. This suggests you need a higher dosage, or alternatively a lower concentration of virus – explain that lignin dosage was reduced along with the virus.

CpGV Technology CpGV Technology Transfer: Transfer: Presentations Presentations Presentations to grower groupsPresentations to grower groups

– WTFRCWTFRC– Tilth, OregonTilth, Oregon– Organic Grower meetingsOrganic Grower meetings– WOPDMCWOPDMC

Technical Presentations Technical Presentations – Society for Invertebrate PathologySociety for Invertebrate Pathology– WC43WC43– Regional Project on Microbial ControlRegional Project on Microbial Control– Entomological Society of AmericaEntomological Society of America

CpGV Technology CpGV Technology Transfer: Publications Transfer: Publications Trade magazinesTrade magazines

– Grower - 2005Grower - 2005– Good Fruit Grower – May 2005Good Fruit Grower – May 2005– Local Ag. Periodicals 2005Local Ag. Periodicals 2005– Tilth Producers Quarterly 2005Tilth Producers Quarterly 2005

Journals Journals – J. Econ. Ent. 2005J. Econ. Ent. 2005– J. Invert. Pathology 2005J. Invert. Pathology 2005– Biol. Control 2004Biol. Control 2004– J. Ent. Soc. B. C. 2005J. Ent. Soc. B. C. 2005– J. Ent. Sci. 2004J. Ent. Sci. 2004– WOPDMC, 2004-2006WOPDMC, 2004-2006

Conclusions and future Conclusions and future workwork

Good population control but there is Good population control but there is room for improvementroom for improvement

Feeding stimulants Feeding stimulants Pear esterPear ester Lignin formulationsLignin formulations ResistanceResistance

– CpGV could provide tool for managing CpGV could provide tool for managing CM resistant to conventional insecticidesCM resistant to conventional insecticides

– Evidence for CM tolerance to CpGVEvidence for CM tolerance to CpGV

a

I would like to finish with some discussion. I should point out this is not the last work, this is basically just 1 year of data. But I think our studies highlight that. Feeding stimulant work was a little disappointing. Studies in UK have shown molasses works well, but only at very high rates. It could be that the high virulence of CpGV may reduce the effectiveness of feeding stimulant additives when compared with other baculoviruses. It is possible that benefits are maximized with very dilute virus concentrations, or when virus persistence has declined to a low level. The PE MEC work was interesting. We didn’t demonstrate a clear benefit in our tests. Maybe higher rates are needed. There is evidence that it may work much better on walnut (Light) or Granny Smith (Knight).Adjuvants: Stilbene florescent brighteners or sprayable particle films (SURROUND kaolin clays) recently developed for duel use as sunburn protectants and management of a range of orchard pests including codling moth should be tested.Lignin-formulations: we clearly showed an effect here. However, the dosage shown effective was 4.3 fold higher compared with the ‘standard’ rate of virus currently used in the region. Because in the present studies the volume of lignin was reduced in line with the virus dosage, the protective effects may have been substantially diluted. The testing of high concentrations of lignin containing reduced concentrations of virus would be worthwhile.

Documents

Optimizing the use of the codling moth granulovirus: Final Report L. Lacey S. Arthurs R. Fritts R. Behle A. Knight