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Improving timing of sprays for codling moth

Jerry Cross

Codling moth

Crepuscular > 15 ºC

Underside of upper wing of male Codling moth

Distinctive rectangular patch underneath upper wing. Not present in the female. Use a pencil or needle to open wing onto sticky base.

Base of wing, where attached to body.

Damage

• Deploy post blossom (early May) • Monitor weekly • Renew lures 4-6 weeks • Threshold: 5/week for 2 weeks not necessarily successive • Ovicides straight away, egg hatch sprays 7-10

days later • Insecticides give 2 wks cover, 3 wks Coragen

Previous methods of timing codling sprays: Sex pheromone traps

Why pheromone-based-trapping needs to be improved?

• Only males are caught, males don’t cause fruit damage

• Proterandry: male’s flight starts in advance • Flight activity by males occurs at lower

temp than egg laying by females • Long-distance activity - pheromone trap

attracts moths from outside the orchard • Heavy insecticide use directed by

pheromone trap monitoring not leading to long term reduction in populations

Bi-Sex lure (Pear ester lure;

DA2313 lure) Ethyl (2E, 4Z)-2,4-decadienoate

• Major odour of ripe pear fruit (not leaves). Minor in apple

• Attracts males and females • Sexing required (not difficult) • Competition with crop • Crop effect: Apple > Pear • Cultivar Effect:

Late vars > Early vars • Looses attractancy through

season

Combo and Triple codling moth lures

Combo = sex pheromone + DA2313 Attracts males and females – used for monitoring the success of sex pheromone MD Triple lure = sex pheromone + DA2313+ Acetic acid As Combo, but supposed to increase catch of females and decrease catch of males

• Temperature sum phenological model predicts emergence and flight • Dusk (21:00-24:00 hr) temps >15 ˚C used to determine periods of egg

laying risk

Current methods of timing codling sprays: RIMpro-Cydia model

• No resistant varieties • Only individuals completing 1st generation development and

laying eggs before end of July can complete a 2nd generation – unlikely in UK

• 2nd generation larvae damage fruit before harvest, even though don’t contribute to next year populations

• Large % of 1st generation larvae diapause • Mature fruits much more susceptible early vars more susceptible 2nd generation more damaging • Control ineffective once larvae inside fruit • Insecticides don’t last so long in hot conditions ( <2 weeks)

Important points

• Relationship between trap catches and damage very variable and erratic. • Regular, direct counting of eggs on fruitlets only reliable way to time/direct sprays • Time consuming, diligence, good eye sight, not difficult • Weekly: 600 fruitlets/orchard for threshold 0.5% infested fruit

But agronomists and growers consider egg monitoring impractical

Optimum treatment timing to reduce overwintering codling moth

(HDC project TF189; 2009-10)

Determine better practical methods for timing sprays of insecticides so reducing overwintering populations and achieving better long term control

Improving codling moth spray timing HDC project TF204 1 April 2012-31 March 2015

Method 1: Pheromone trap Method 2: Rimpro-Cydia Method 3: Rimpro-Cydia + pheromone trap

Plot 101 Trap

Plot 103 Rimpro

Plot 102 Rimpro+trap

Codling sex pheromone trap Codling combo trap Summer fruit tortrix sex pheromone trap Fruit tree tortrix sex pheromone trap

Site 1: Amsbury Farm; MM106 Bramley; 1 ha; 666 trees/ha

Plot 202 Trap Plot 203

Rimpro+trap


Plot 201 Rimpro

Site 2: W. Pike Fish Fm; M9 Jonagold; 2.7 ha; 2500 trees/ha

Plot 303 Trap

Plot 302 Rimpro

Plot 301 Rimpro+trap


Site 3: Wenderton Farm; M9 Kanzi; 7 ha; 2500 trees/ha

Pheromone trap catches 2012

RIMpro predictions 2012

Sprays 2012

Trap RIMpro Trap+RIMpro Amsbury 6 Jun Runner 6 Jun Runner 6 Jun Runner 27 Jun Insegar 3 Aug Coragen W Pike Fish 21 Jun Insegar 28 Jun Insegar 12 Jul Coragen 3 Aug Steward Wenderton 19 Jun Insegar 27 Jun Insegar 4 Jul Steward

% fruit damage 2012

Trap RIMpro Trap+RIMpro Amsbury 16.6 3.6 10.7 W Pike Fish 0.7 0.1 0.5 Wenderton 3.7 0.7 0.6

• Just below threshold trap catches caused bad damage, especially in Aug – Sep. Condition of 5/trap in two weeks, not necessarily successive, not quite met

• Pheromone trap threshold too high and complex Simplify to single value and reduce for 2nd generation May – July: 5/week Aug – Sep: 3/week • Adjusted threshold adopted in 2013-14

2012 Conclusions – trap threshold

• Using RIMpro-cydia model alone will result in large numbers of sprays in warm year

• In 2012, RIMpro-cydia model failed to predict early August attack and bad damage resulted at Amsbury. Feed through from 1st into 2nd generation incorrect.

• Parameters adjusted by model provider (Bio Fruit Advies, NL) for 2013

2012 Conclusions – RIMpro-cydia

Sprays 2013

Trap RIMpro Trap+RIMpro Amsbury 28 Jun Coragen 28 Jun Coragen 28 Jun Coragen 23 Jul Coragen 23 Jul Coragen 23 Jul Coragen W Pike Fish 19 Jun Coragen 25 Jun Coragen 25 Jun Coragen 9 Jul Steward 16 Jul Steward 16 Jul Steward 2 Aug Coragen Wenderton 19 Jun chlorp’fos 19 Jun chlorp’fos 19 Jun chlorp’fos 3 Jul Coragen 3 Jul Coragen 3 Jul Coragen 18 Jul Steward 18 Jul Steward 18 Jul Steward 2 Aug Coragen

% fruit damage 2013


• Simplified lower threshold satisfactory: Single value May – July: 5/week Aug – Sep: 3/week • High level of damage at Amsbury suggested

interval between sprays (cover period) should be reduced where bad damage previous year


• No second generation correctly forecast by model

• Model alone resulted in one more insecticide being applied at two sites, with no obvious benefit

• Model upgraded to online version by Bio Fruit Advies


Sprays 2014

Trap RIMpro Trap+RIMpro Amsbury 31 May Coragen 10 Jun Coragen 19 Jun Steward 19 Jun Steward 25 Jun Steward 10 Jul Coragen 10 Jul Coragen 16 Jul Coragen 25 Jul Steward 25 Jul Steward 15 Aug Steward W Pike Fish 5 Jun Coragen 16 Jun Coragen 16 Jun Coragen 26 Jun Steward 3 Jul Explicit 28 Aug Steward 16 Jul Coragen 13 Aug Explicit 28 Aug Steward Wenderton 18 Jun Coragen 18 Jun Coragen 18 Jun Coragen 4 Jul Steward 21 Jul Coragen 15 Aug Explicit 30 Aug Steward

% fruit damage 2014


• Simplified lower threshold satisfactory: Single value May – July: 5/week Aug – Sep: 3/week • High level of damage at Amsbury stregnthened

evidence that interval between sprays (cover period) should be reduced where bad damage previous year


• Model performed very differently in 2014 • Scale altered, sensitivity significantly increased • Model forecast near continuous egg laying risks

resulting in large numbers of sprays on RIMpro only plot

• Model forecast strong second generation but no evidence from traps or damage that this occurred. Growers gave up spraying!

• Bio Fruit Advies confirmed that model had altered due to reprogramming for online version


Total no. codling sprays 2011-14

Trap RIMpro Trap+RIMpro Amsbury 7 9 6 W Pike Fish 5 11 4 Wenderton 3 11 5 Average no./season 1.8 3.4 1.7

Average % fruit damage

Trap RIMpro Trap+RIMpro Amsbury 7.7 3.2 6.2 W Pike Fish 0.8 0.8 1.2 Wenderton 1.2 0.5 0.5 All 3 sites 3.2 1.5 2.6

Average UK orchard gross output 35 t/ha @ £934/t = £29,208/ha (Nix, 2013) Every 1% loss = £292/ha, >3x the cost of a typical codling insecticide spray!

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Combo males Combo females Triple males Triple females Sex phero males

Gra

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k 24

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2014

Lure performance 2014

• Sex pheromone lures best for males • Combo and Triple lures catch females as

well, but in small numbers

• Combined use of sex pheromone trap and model ultimately the best method

• But model needs to be sorted out and calibrated before this method can be recommended.

• Until this has been achieved, continue to use sex pheromone traps alone with simplified lower threshold satisfactory:

Single value May – July: 5/week Aug – Sep: 3/week • Combo lures need further study before they can be

recommended • Reduce interval between sprays (cover period) where

bad damage (>>1%) previous year or in hot weather: 2 weeks Coragen, 10 days others?

Overall conclusions

New HDC 5 year Tree Fruit P&D project at EMR Large scale trial on 2 farms testing codling + tortrix MD (BASF RAK4) ± granulovirus and nematodes for codling & tortrix Calibrate the RIMpro cydia model?

Future work

Thanks

Growers Clive Baxter, Alan Burbridge, Russell Graydon, Mark Holden, James Smith, Paul Smith Industry Paul Bennett, Tim Biddlecombe Funders Horticultural Development Company

Download - Improving timing of sprays for codling moth. Monitoring... · Amsbury. Feed through from 1st into 2nd generation incorrect

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