Psyllid Management: Tactics and Timing

Phil Stansly, SWFREC Immokalee

Outline• Dormant season

– Freeze effects–Area wide sprays

• Growing season–Psyllid monitoring–Aerial vs Ground–Oil option

• Grower survey• Management plan

Freeze Effects on Psyllids

They’re still out there; NOW is the time to spray!

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Before After

Freeze Effects on Psyllids:Scott Croxton

Cooperative Dormant Spray in SW Florida Phil Stansly, Alejandro Arevalo SWFREC Immokalee

Paul Mears DPI-CHRP Immokalee; Mongi Zekri UF Coop. Extension; Gulf Coast Citrus Growers Association

Area-Wide Dormant Sprays

• A dormant spray is a foliar application of broad-spectrum insecticide directed at over-wintering adult psyllids.

• Dormant sprays attack the psyllid population at its weakest point and when beneficial insects are least exposed.– Collateral damage to Tamarixia

• The larger the treated area of citrus, the greater the effectiveness of dormant sprays.

• Broad spectrum insecticides are needed– Rotate modes of action (pyrethroids, OPs Carbamates)– Chose from recommended products based on PHI and previous

history

Area Wide Dormant Spray in SW Florida

Dec 08 – Feb 09 Oct - Dec 09

Application Acreage Acreage

Aerial 103,471 68,500

Ground(estimated)

42,200 28,000

Total 145,671 96,500

Area Wide Dormant Applicationsin SW Florida

* Estimation based on survey of 27 growers in 2009 covering 106,000 acres

Field Survey Results:Average ACP Adults per 10 Tap Samples

Before and After Dormant Sprays

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Adults per 10 taps

Air (55)

Ground (13)

Untreated (1)

50%

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110%74%60%

83%

Grower Survey on ACP Management: Jul-Sep 2009

• 27 Surveys received summer 2009• 106,148 acres covered • Groves from 40 to 18,000 acres• Survey to be repeated in 2010.

Dormant sprays 2008-2009: at least 1 100%Average number 1.6Aerial 71%

Voluntary Area Wide Dormant Spray in SW Florida: Conclusions

• Excellent buy-in by growers: 103,470 acres sprayed by air and almost all the rest by ground 2008-09.

• Immediate psyllid reduction of 60%, 74% (aerial, ground) and only a 1.5x, 1.8x increase by May, compared to a 28x (2,800%) increase in an untreated block.

• Aug 2009 survey: 96% of growers (99.9% of acreage) said they would put out at least on dormant spray this season.

When to Spray Post-bloom? ACP Monitoring Programhttp://swfrec.ifas.ufl.edu/entlab/

Visual inspection− Do next− 10 flush per stop

Tap Sample− Do first − 10 per stop

http://swfrec.ifas.ufl.edu/entlab/programs/index.htmhttp://swfrec

Equipment

Hand lens: For seeing small eggs and nymp

Piece of PVC (optional)For hitting branch

Clipboard:For catching adults and recording data

Sample location

• 1 Block

• 10 Stops– 5 border– 5 inside

• 10 trees

Tap Sampling

3 taps per sample1 tap sample per tree10 trees per stop10 stops per block (5 in the borders + 5 inside)

Visual inspection

• Look for young flush (shoots)• Observe 10 flush per stop

–If 10 not available record number found in 20 trees

• Record–# of infested flush (any psyllid stage)–# of observed flush –# of trees needed to find 10 flush (Max 20)

Datasheet http://swfrec.ifas.ufl.edu/entlab/

Survey Results:Scouting for Psyllids

More than 3 times 85%Tap 95%TapFlush Inspection

95%76%

Sticky traps 14%Stickyy apsy ratrSweep net

%14%9%

Adults first priority• Responsible for spread of HLB• Target of most sprays• Best treated prior to flush

Tap test rapid and effective• Rain or shine, flush or no flush• 10 trees / location, 10 locations / block = 100 taps

13-Jun19-Jun

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7-Jul15-Jul0

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101214161820

How to spray Post-bloom154 Acres, aerial plots 15 beds wide x 1200 ft, groundplots 3 beds Val x Car.Ground spray 15 June 125 gal/ac speed sprayerAerial spray 16 June 10 gal/ac.

Aerial Grou

Adul

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taps

Precount

Broad-spectrum products worked by air and ground. Selective products by ground only. Mustang not good in summer.

What to Spray Post Bloom?

• Selective insecticides best, especially early post bloom–Greatest activity of natural enemies

• Options: Delegate, Movento, Micromite, Actara, Agrimec, Oil alone

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Satisfaction with SprayProgram and Incidenceof Secondary Pests

59%18%

4% 4%

15%Somewhat Satisfied

Very Satisfied

Very Dissatisfied

Somewhat Dissatisfied

LV Applications of Oil and Azadirachtin 2008A. Arevalo

• 65 Acre block, 5 bed plots, treated 5 times once every 2 weeks beginning June 24

• “London Fogger” (Beck Bros.) 1 gal/acre oil only or with 12 oz Aza-Direct

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Oil Aza-Direct + Oil Control

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All flush on 20 trees/plot Aug. 1

ULV Applications of Oil 2009Preliminary Results

• 3 treatments – Proptec P400D– London Fogger model 18-20– Control

• Applications every 2 to 4 weeks.

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Conclusions • Aerial vs. Ground

–Broad-spectrum is were generally effective either way

–Selective insecticides tended to be more effective by conventional ground application

• LV 435 Horticultural oil (2 gal./ac.)–Recurrent applications of LV 435 oil

maintained low ACP populations

Post-Bloom:BeneficialsActive: Only Soft Pesti-cidesif nec- essary. Mass Release?

Psyllid Manangement Plan for Mature Citrus• Monitor populations year round • Dormant spray(s) with short PHI adulticide• No sprays on flushes• Only soft chemistry post bloom• Oil program option throughout growing season• OPs in summer and before fall flush if necessary

Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct

Dormant Season:PyrethroidsCarbamates(short PHIs)Soil applicationsof Aldicarb

Spring Flush & Bloom: No Spray

Summer:OPs, carbamatesor selective insecticides if needed

Summer Flush: No Spray

Fall Flush: No Spray

Oil Option

Post-bloom:selective insecticides if needed:Imidaclopriddrench young trees