1. Entomology Research Updates Psyllid transmission of greening and chemical control of psyllids Michael E. Rogers UF / IFAS / Citrus Research and Education Center, Lake Alfred Michael E. Rogers UF / IFAS / Citrus Research and Education Center, Lake Alfred

2. Psyllid / HLB Studies (current progress) Pathogen acquisition by adults and nymphs –Laboratory –Field Seasonality of HLB infected psyllids –survey work Effects of insecticides on pathogen transmission Results of multi-pest efficacy trial Pathogen acquisition by adults and nymphs –Laboratory –Field Seasonality of HLB infected psyllids –survey work Effects of insecticides on pathogen transmission Results of multi-pest efficacy trial

3. Psyllid Acquisition Rates (laboratory studies) Psyllids which fed as adults on HLB (+) plants Average acquisition rate of 20-30% Psyllids which fed as adults on HLB (+) plants Average acquisition rate of 20-30% Greening Infected Adult Psyllids % infected Feeding Time (days)

4. Psyllid Acquisition Rates (laboratory studies) Adult psyllid reared on HLB (+) plants (nymphs fed entire time on infected plant) Percentage of HLB (+) adult psyllids ranged from 11.6% to 100% Adult psyllid reared on HLB (+) plants (nymphs fed entire time on infected plant) Percentage of HLB (+) adult psyllids ranged from 11.6% to 100%

5. Psyllid Acquisition Rates (field studies) Caging Studies –Acquisition by adults vs nymphs Caging Studies –Acquisition by adults vs nymphs

6. Psyllid Acquisition Rates (field studies) Adult psyllids caged on HLB (+) plants –1 out of 1,000+ psyllids tested HLB (+) Adult psyllids reared from nymphs on HLB (+) plants –Percentage of adults testing HLB (+) ranged from 0% to 100% –Variation probably due to differences in pathogen levels in different parts of the plant Adult psyllids caged on HLB (+) plants –1 out of 1,000+ psyllids tested HLB (+) Adult psyllids reared from nymphs on HLB (+) plants –Percentage of adults testing HLB (+) ranged from 0% to 100% –Variation probably due to differences in pathogen levels in different parts of the plant

7. Seasonal Psyllid Infection Rates Monthly collections of “wild” psyllid populations DNA extraction / PCR of psyllids to detect presence of HLB pathogen 8 grove sites in 5 Florida counties including: –DeSoto, Highlands, Okeechobee, Polk and St. Lucie counties HLB (+) trees have been found in all of these locations Monthly collections of “wild” psyllid populations DNA extraction / PCR of psyllids to detect presence of HLB pathogen 8 grove sites in 5 Florida counties including: –DeSoto, Highlands, Okeechobee, Polk and St. Lucie counties HLB (+) trees have been found in all of these locations

8. 0 500 1000 1500 2000 2500 3000 3500 4000 4500 JanFebMarAprMayJunJulAug 0 0.001 0.002 0.003 0.004 0.005 0.006 Infection Rate Sample Size (N) Total # psyllids sampled Psyllid Infection rate and sample size averaged for all Florida sites. Preliminary Data (Jan-Jul 2008) 0.2% 0.5% the highest monthly infection rate found in a single grove thus far was 1.6%; high number of HLB (+) trees No infected psyllids were found in most groves; these groves did have varying degrees of HLB management programs Small sample size

9. Summary of Results…to date Overall psyllid infection rates in the field are likely less than 1% Only saw rates >1% where HLB infected trees were still present There may indeed be some fluctuation in abundance of infected psyllids throughout the year – preliminary data Overall psyllid infection rates in the field are likely less than 1% Only saw rates >1% where HLB infected trees were still present There may indeed be some fluctuation in abundance of infected psyllids throughout the year – preliminary data

10. Summary of Results…to date Acquisition rates by adult psyllids in field appear to be low Higher rates in lab (plant health) Very high rates of infection are possible from adults reared as nymphs on HLB (+) plants; will vary based on HLB levels in plant Acquisition rates by adult psyllids in field appear to be low Higher rates in lab (plant health) Very high rates of infection are possible from adults reared as nymphs on HLB (+) plants; will vary based on HLB levels in plant

11. Implications for Managing HLB ? IF…you cant control 100% of the psyllids 100% of the time IF…100% (or even 50%) of the psyllid nymphs on HLB (+) trees acquire the pathogen CAN HLB be managed without removing infected trees? IF…you cant control 100% of the psyllids 100% of the time IF…100% (or even 50%) of the psyllid nymphs on HLB (+) trees acquire the pathogen CAN HLB be managed without removing infected trees?

12. Vector Management using insecticides Preventing transmission Reducing overall psyllid populations Preventing transmission Reducing overall psyllid populations

13. Can insecticides prevent pathogen transmission? Soil-applied systemic insecticides –Mortality caused by feeding prior to transmission? Foliar insecticides –Does contact with residues cause mortality prior to transmission? If insecticides can prevent transmission, how long does such protection last? –Effects of residue degradation? Soil-applied systemic insecticides –Mortality caused by feeding prior to transmission? Foliar insecticides –Does contact with residues cause mortality prior to transmission? If insecticides can prevent transmission, how long does such protection last? –Effects of residue degradation?

14. Ongoing studies: imidacloprid treated and untreated plants challenged with HLB (+) psyllids

15. Ongoing studies: Currently holding more than 100 plants; no PCR positives to-date Positive transmission results could take 8-12 months Early symptoms can be a bit confusing Currently holding more than 100 plants; no PCR positives to-date Positive transmission results could take 8-12 months Early symptoms can be a bit confusing

16. Huh?!?

17. Electrical Penetration Graph (EPG) – measure psyllid feeding

18. EPG Studies Determine exact feeding time required for pathogen transmission / acquisition Determine whether insecticides can disrupt feeding prior to transmission Determine how long insecticides (residues) provide disruption of psyllid feeding / pathogen transmission Determine exact feeding time required for pathogen transmission / acquisition Determine whether insecticides can disrupt feeding prior to transmission Determine how long insecticides (residues) provide disruption of psyllid feeding / pathogen transmission

20. Control of Asian citrus psyllid, citrus leafminer and citrus rust mite Trial 2008-10 M.E. Rogers UF / IFAS / Citrus Research & Education Center, Lake Alfred

21. Treatments 1Dimethoate 4E + LI 7001 pint/A ; 0.25% v/v 2Dimethoate 4E + LI 7002 pints / A ; 0.25% v/v 3Agri-mek 0.15EC + FC 435 oil20 oz / A ; 2% v/v 4Agri-mek 0.15EC + FC 435 oil10 oz / A ; 2% v/v 5Sevin XLR + LI 7002 quarts/A ; 0.25% v/v 6Provado 1.6F + LI 70010 oz / A ; 0.25% v/v 7Movento 240SC + LI 70010 oz / A ; 0.25% v/v 8Movento 240SC + FC 435 oil10 oz / A ; 3% v/v 9Envidor 240SC15 oz / A 10Imidan 70W + LI 7001.5 lbs / A ; 0.25% v/v 11Mustang 1.5EW4.3 oz / A 12Danitol 2.4EC16 oz / A 13Micromite 80WGS + FC435 oil6.25 oz / A ; 2% v/v 14Portal 0.4EC + FC 435 oil4 pints / A ; 2% v/v 15Delegate 25WG + FC 435 oil4 oz / A ; 2% v/v 16Lorsban 4E5 pints / A ; 2% v/v 17Untreated---

22. Trial Location ConservII – MidFlorida Citrus Research Foundation Grove Variety – ‘earlygold’ Treatment dates: June 24-25, 2008 Trial still under evaluation (8/8/08) Plot size: 15 trees (3 x 5) A foliar fertilizer was tank-mixed with all treatments (DiamondR Ultra M2F; Sulfur 3.2%; Iron 1.6%; Mn 2.0%; Zn 2.4%)

31. Pesticide active ingredient Target pest Effects on natural enemies Mode of Action 1 PsyllidLeafminerRust MitesSpider Mites Root Weevil Adults Scale InsectsMealybugs Abamectin + oil6+++++,R ++ (oil) medium Acetamiprid4-+++,R--?+++medium Aldicarb1A+++,R- +++---low Carbaryl1A+++,R-+? +high Chlorpyrifos1B+++,R++-+ high Diflubenzuron15+++++,R - --low Dimethoate1B+++---?+++,R+high Fenbutatin oxide12--+++,R ---low Fenpropathrin3+++,R-++ -+high Imidacloprid (soil application, nonbearing) 4+++,R --++++low Imidacloprid (foliar application) 4+++,R+---+++medium Petroleum oilNR+++,R +++(eggs)++,R+low Phosmet1B+++-+?+++,R??medium/high Pyridaben21-?+++,R ---high Spinosad5-+++,R-----low Spinetoram5++++++,R-????low Spirodiclofen23--+++,R ?--low SulfurNR--+++,R+++-??high (short term) 1 Mode of action class for citrus pesticides from the Insecticide Resistance Action Committee; NR = no resistance potential (R) = product recommended for control of pest in Florida Citrus Pest Management Guide (+++) = good control of pest (++) = short-term control of pest (+) = low levels of pest suppression (-) = no observed control of pest (?) = insufficient data available List of insecticides and miticides recommended for use in the Florida Citrus Pest Management Guide and their effects on citrus pests and their natural enemies For more information, contact the University of Florida, IFAS, Citrus Research and Education Center 863-956-1151, www.crec.ifas.ufl.edu, or your local county citrus extension agent. Created by: Michael E. Rogers, revised August 2008 Photo Credit: University of Florida

32. Tree HeightRate Product/A*Applications per seasonOunces per treeTrees per ounce Imidacloprid 2F 2 ft – 4 ft8 fl oz40.057 fl oz17.5 trees 4 ft – 6 ft16 fl oz20.114 fl oz8.77 trees Imidacloprid 4.6F (Admire PRO) 2 ft – 4 ft3.5 fl oz40.025 fl oz40 trees 4 ft – 6 ft7 fl oz20.05 fl oz20 trees *Rates based on 140 trees per acre Imidacloprid soil drench rates for solid plantings on nonbearing citrus Active IngredientRestricted entry interval (REI)Pre-harvest interval (PHI) Abamectin12 hours7 days Acetamiprid12 hours7 days Aldicarb48 hours0; 30 days lemons Carbaryl12 hours5 days Chlorpyrifos5 days21 days Diflubenzuron12 hours21 days Dimethoate48 hours15 days Fenbutatin oxide48 hours7 days Fenpropathrin24 hours1 day Imidacloprid12 hours0 Phosmet24 hours7 days Pyridaben12 hours7 days Spinosad4 hours1 day Spinetoram4 hours1 day Spirodiclofen12 hours7 days Sulfur12 hours0 Use pesticides safely. Read and follow directions on the manufacturer’s label. Restricted Entry Interval (REI) and Pre-Harvest Interval (PHI) for products listed on front page Additional citrus pest management information can be found in the Florida Citrus Pest Management Guide available online at http://www.crec.ifas.ufl.edu/extension/pest/index.htm

33. Acknowledgements Florida Citrus Production Research Advisory Council Citrus Growers (numerous) Florida Citrus Production Research Advisory Council Citrus Growers (numerous)

34. Acknowledgements Lab Members: Harry Anderson Sr. Biol. Sci. Percivia “Peaches” Mariner Research Assistant Rhonda Schumann Sr. Chemist Dalia Shawer Research Assistant Tim Ebert Post-doctoral Research Assoc. Antonios Tsagkarakis Post-doctoral Research Assoc. Rosana Serikawa Ph.D. Student